Ini adalah Panduan Pengembang AWS CDK v2. CDK v1 yang lebih lama memasuki pemeliharaan pada 1 Juni 2022 dan mengakhiri dukungan pada 1 Juni 2023.
Terjemahan disediakan oleh mesin penerjemah. Jika konten terjemahan yang diberikan bertentangan dengan versi bahasa Inggris aslinya, utamakan versi bahasa Inggris.
# Token dan AWS CDK
Dalam AWS Cloud Development Kit (AWS CDK), *token* adalah placeholder untuk nilai yang tidak diketahui saat mendefinisikan konstruksi atau mensintesis tumpukan. Nilai-nilai ini akan sepenuhnya diselesaikan pada penerapan, ketika infrastruktur Anda yang sebenarnya dibuat. Saat mengembangkan aplikasi AWS CDK, Anda akan bekerja dengan token untuk mengelola nilai-nilai ini di seluruh aplikasi Anda.
## Contoh token
Berikut ini adalah contoh tumpukan CDK yang mendefinisikan konstruksi untuk bucket Amazon Simple Storage Service (Amazon S3). Karena nama bucket kami belum diketahui, nilai untuk `bucketName` disimpan sebagai token:
**Example**
```
import * as cdk from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as s3 from 'aws-cdk-lib/aws-s3';
export class CdkDemoAppStack extends cdk.Stack {
constructor(scope: Construct, id: string, props?: cdk.StackProps) {
super(scope, id, props);
// Define an S3 bucket
const myBucket = new s3.Bucket(this, 'myBucket');
// Store value of the S3 bucket name
const myBucketName = myBucket.bucketName;
// Print the current value for the S3 bucket name at synthesis
console.log("myBucketName: " + myBucketName);
}
}
```
```
const { Stack, Duration } = require('aws-cdk-lib');
const s3 = require('aws-cdk-lib/aws-s3');
class CdkDemoAppStack extends Stack {
constructor(scope, id, props) {
super(scope, id, props);
// Define an S3 bucket
const myBucket = new s3.Bucket(this, 'myBucket');
// Store value of the S3 bucket name
const myBucketName = myBucket.bucketName;
// Print the current value for the S3 bucket name at synthesis
console.log("myBucketName: " + myBucketName);
}
}
module.exports = { CdkDemoAppStack }
```
```
from aws_cdk import (
Stack
)
from constructs import Construct
from aws_cdk import aws_s3 as s3
class CdkDemoAppStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
# Define an S3 bucket
my_bucket = s3.Bucket(self, "myBucket")
# Store the value of the S3 bucket name
my_bucket_name = my_bucket.bucket_name
# Print the current value for the S3 bucket name at synthesis
print(f"myBucketName: {my_bucket_name}")
```
```
package com.myorg;
import software.constructs.Construct;
import software.amazon.awscdk.Stack;
import software.amazon.awscdk.StackProps;
import software.amazon.awscdk.services.s3.Bucket;
import java.util.Map;
public class CdkDemoAppStack extends Stack {
public CdkDemoAppStack(final Construct scope, final String id) {
this(scope, id, null);
}
public CdkDemoAppStack(final Construct scope, final String id, final StackProps props) {
super(scope, id, props);
// Define an S3 bucket
Bucket myBucket = Bucket.Builder.create(this, "myBucket")
.build();
// Store the token for the bucket name
String myBucketName = myBucket.getBucketName();
// Print the token at synthesis
System.out.println("myBucketName: " + myBucketName);
}
}
```
```
using Amazon.CDK;
using Constructs;
using Amazon.CDK.AWS.S3;
namespace CdkDemoApp
{
public class CdkDemoAppStack : Stack
{
internal CdkDemoAppStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
{
// Define an S3 bucket
var myBucket = new Bucket(this, "myBucket");
// Store the token for the bucket name
var myBucketName = myBucket.BucketName;
// Print the token at synthesis
System.Console.WriteLine($"myBucketName: {myBucketName}");
}
}
}
```
```
package main
import (
"fmt"
"github.com/aws/aws-cdk-go/awscdk/v2"
"github.com/aws/aws-cdk-go/awscdk/v2/awss3"
"github.com/aws/constructs-go/constructs/v10"
"github.com/aws/jsii-runtime-go"
)
type CdkDemoAppStackProps struct {
awscdk.StackProps
}
func NewCdkDemoAppStack(scope constructs.Construct, id string, props *CdkDemoAppStackProps) awscdk.Stack {
var sprops awscdk.StackProps
if props != nil {
sprops = props.StackProps
}
stack := awscdk.NewStack(scope, &id, &sprops)
// Define an S3 bucket
myBucket := awss3.NewBucket(stack, jsii.String("myBucket"), &awss3.BucketProps{})
// Store the token for the bucket name
myBucketName := myBucket.BucketName()
// Print the token at synthesis
fmt.Println("myBucketName: ", *myBucketName)
return stack
}
// ...
```
Ketika kita menjalankan `cdk synth` untuk mensintesis tumpukan kita, nilai untuk `myBucketName` akan ditampilkan dalam format token. `${Token[TOKEN.<1234>]}` Format token ini adalah hasil dari bagaimana AWS CDK mengkodekan token. Dalam contoh ini, token dikodekan sebagai string:
```
$ cdk synth --quiet
myBucketName: ${Token[TOKEN.21]}
```
Karena nilai untuk nama bucket kami tidak diketahui saat sintesis, token dirender sebagai`myBucket`. AWS CloudFormation Template kami menggunakan fungsi `Ref` intrinsik untuk mereferensikan nilainya, yang akan diketahui saat penerapan:
```
Resources:
myBucket<5AF9C99B>:
# ...
Outputs:
bucketNameOutput:
Description: The name of the S3 bucket
Value:
Ref: myBucket<5AF9C99B>
```
Untuk informasi selengkapnya tentang cara hash unik dihasilkan, lihat [Generated logical IDs di AWS CloudFormation template Anda](configure-synth.md#how-synth-default-logical-ids).
## Melewati token
Token dapat diedarkan seolah-olah itu adalah nilai aktual yang mereka wakili. Berikut ini adalah contoh yang meneruskan token untuk nama bucket kami ke konstruksi untuk fungsi AWS Lambda:
**Example**
```
import * as cdk from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as s3 from 'aws-cdk-lib/aws-s3';
import * as lambda from 'aws-cdk-lib/aws-lambda';
export class CdkDemoAppStack extends cdk.Stack {
constructor(scope: Construct, id: string, props?: cdk.StackProps) {
super(scope, id, props);
// Define an S3 bucket
const myBucket = new s3.Bucket(this, 'myBucket');
// ...
// Define a Lambda function
const myFunction = new lambda.Function(this, "myFunction", {
runtime: lambda.Runtime.NODEJS_20_X,
handler: "index.handler",
code: lambda.Code.fromInline(`
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
`),
functionName: myBucketName + "Function", // Pass token for the S3 bucket name
environment: {
BUCKET_NAME: myBucketName, // Pass token for the S3 bucket name
}
});
}
}
```
```
const { Stack, Duration } = require('aws-cdk-lib');
const s3 = require('aws-cdk-lib/aws-s3');
const lambda = require('aws-cdk-lib/aws-lambda');
class CdkDemoAppStack extends Stack {
constructor(scope, id, props) {
super(scope, id, props);
// Define an S3 bucket
const myBucket = new s3.Bucket(this, 'myBucket');
// ...
// Define a Lambda function
const myFunction = new lambda.Function(this, 'myFunction', {
runtime: lambda.Runtime.NODEJS_20_X,
handler: 'index.handler',
code: lambda.Code.fromInline(`
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
`),
functionName: myBucketName + 'Function', // Pass token for the S3 bucket name
environment: {
BUCKET_NAME: myBucketName, // Pass token for the S3 bucket name
}
});
}
}
module.exports = { CdkDemoAppStack }
```
```
from aws_cdk import (
Stack
)
from constructs import Construct
from aws_cdk import aws_s3 as s3
from aws_cdk import aws_lambda as _lambda
class CdkDemoAppStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
# Define an S3 bucket
my_bucket = s3.Bucket(self, "myBucket")
# ...
# Define a Lambda function
my_function = _lambda.Function(self, "myFunction",
runtime=_lambda.Runtime.NODEJS_20_X,
handler="index.handler",
code=_lambda.Code.from_inline("""
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
"""),
function_name=f"{my_bucket_name}Function", # Pass token for the S3 bucket name
environment={
"BUCKET_NAME": my_bucket_name # Pass token for the S3 bucket name
}
)
```
```
package com.myorg;
import software.constructs.Construct;
import software.amazon.awscdk.Stack;
import software.amazon.awscdk.StackProps;
import software.amazon.awscdk.services.s3.Bucket;
import software.amazon.awscdk.services.lambda.Code;
import software.amazon.awscdk.services.lambda.Function;
import software.amazon.awscdk.services.lambda.Runtime;
import java.util.Map;
public class CdkDemoAppStack extends Stack {
public CdkDemoAppStack(final Construct scope, final String id) {
this(scope, id, null);
}
public CdkDemoAppStack(final Construct scope, final String id, final StackProps props) {
super(scope, id, props);
// Define an S3 bucket
Bucket myBucket = Bucket.Builder.create(this, "myBucket")
.build();
// ...
// Define a Lambda function
Function myFunction = Function.Builder.create(this, "myFunction")
.runtime(Runtime.NODEJS_20_X)
.handler("index.handler")
.code(Code.fromInline(
"exports.handler = async function(event) {" +
"return {" +
"statusCode: 200," +
"body: JSON.stringify('Hello World!')," +
"};" +
"};"
))
.functionName(myBucketName + "Function") // Pass the token for the s3 bucket to the function construct
.environment(Map.of("BUCKET_NAME", myBucketName)) // Pass the bucket name as environment variable
.build();
}
}
```
```
using Amazon.CDK;
using Constructs;
using Amazon.CDK.AWS.S3;
using Amazon.CDK.AWS.Lambda;
using System;
using System.Collections.Generic;
namespace CdkDemoApp
{
public class CdkDemoAppStack : Stack
{
internal CdkDemoAppStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
{
// Define an S3 bucket
var myBucket = new Bucket(this, "myBucket");
// ...
// Define a Lambda function
var myFunction = new Function(this, "myFunction", new FunctionProps
{
Runtime = Runtime.NODEJS_20_X,
Handler = "index.handler",
Code = Code.FromInline(@"
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
"),
// Pass the token for the S3 bucket name
Environment = new Dictionary
{
{ "BUCKET_NAME", myBucketName }
},
FunctionName = $"{myBucketName}Function" // Pass the token for the s3 bucket to the function construct
});
}
}
}
```
```
package main
import (
"fmt"
"github.com/aws/aws-cdk-go/awscdk/v2"
"github.com/aws/aws-cdk-go/awscdk/v2/awslambda"
"github.com/aws/aws-cdk-go/awscdk/v2/awss3"
"github.com/aws/constructs-go/constructs/v10"
"github.com/aws/jsii-runtime-go"
)
type CdkDemoAppStackProps struct {
awscdk.StackProps
}
func NewCdkDemoAppStack(scope constructs.Construct, id string, props *CdkDemoAppStackProps) awscdk.Stack {
var sprops awscdk.StackProps
if props != nil {
sprops = props.StackProps
}
stack := awscdk.NewStack(scope, &id, &sprops)
// Define an S3 bucket
myBucket := awss3.NewBucket(stack, jsii.String("myBucket"), &awss3.BucketProps{})
// ...
// Define a Lambda function
myFunction := awslambda.NewFunction(stack, jsii.String("myFunction"), &awslambda.FunctionProps{
Runtime: awslambda.Runtime_NODEJS_20_X(),
Handler: jsii.String("index.handler"),
Code: awslambda.Code_FromInline(jsii.String(`
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
`)),
FunctionName: jsii.String(fmt.Sprintf("%sFunction", *myBucketName)), // Pass the token for the S3 bucket to the function name
Environment: &map[string]*string{
"BUCKET_NAME": myBucketName,
},
})
return stack
}
// ...
```
Saat kita mensintesis template kita, fungsi `Ref` dan `Fn::Join` intrinsik digunakan untuk menentukan nilai, yang akan diketahui saat penerapan:
```
Resources:
myBucket<5AF9C99B>:
Type: AWS::S3::Bucket
# ...
myFunction<884E1557>:
Type: AWS::Lambda::Function
Properties:
# ...
Environment:
Variables:
BUCKET_NAME:
Ref: myBucket<5AF9C99B>
FunctionName:
Fn::Join:
- ""
- - Ref: myBucket<5AF9C99B>
- Function
# ...
```
## Cara kerja pengkodean token
Token adalah objek yang mengimplementasikan [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.IResolvable.html)antarmuka, yang berisi satu `resolve` metode. Selama sintesis, AWS CDK memanggil metode ini untuk menghasilkan nilai akhir untuk token di CloudFormation template Anda.
**catatan**
Anda jarang akan bekerja secara langsung dengan `IResolvable` antarmuka. Anda kemungkinan besar hanya akan melihat versi token yang disandikan string.
### Jenis pengkodean token
Token berpartisipasi dalam proses sintesis untuk menghasilkan nilai arbitrer dari jenis apa pun. Fungsi lain biasanya hanya menerima argumen tipe dasar, seperti `string` atau`number`. Untuk menggunakan token dalam kasus ini, Anda dapat menyandikannya menjadi salah satu dari tiga jenis dengan menggunakan metode statis pada [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html)kelas.
+ [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html#static-aswbrstringvalue-options](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html#static-aswbrstringvalue-options)untuk menghasilkan pengkodean string (atau memanggil `.toString()` objek token).
+ [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html#static-aswbrlistvalue-options](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html#static-aswbrlistvalue-options)untuk menghasilkan pengkodean daftar.
+ [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html#static-aswbrnumbervalue](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html#static-aswbrnumbervalue)untuk menghasilkan pengkodean numerik.
Ini mengambil nilai arbitrer, yang bisa berupa`IResolvable`, dan menyandikannya menjadi nilai primitif dari tipe yang ditunjukkan.
**penting**
Karena salah satu tipe sebelumnya berpotensi menjadi token yang dikodekan, berhati-hatilah saat Anda mengurai atau mencoba membaca isinya. Misalnya, jika Anda mencoba mengurai string untuk mengekstrak nilai darinya, dan string adalah token yang dikodekan, penguraian Anda gagal. Demikian pula, jika Anda mencoba menanyakan panjang array atau melakukan operasi matematika dengan angka, Anda harus terlebih dahulu memverifikasi bahwa itu bukan token yang dikodekan.
## Cara memeriksa token di aplikasi Anda
Untuk memeriksa apakah suatu nilai memiliki token yang belum terselesaikan di dalamnya, panggil metode [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html#static-iswbrunresolvedobj](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Token.html#static-iswbrunresolvedobj)(Python`is_unresolved`:). Berikut ini adalah contoh yang memeriksa apakah nilai untuk nama bucket Amazon S3 kami adalah token. Jika bukan token, kami kemudian memvalidasi panjang nama bucket:
**Example**
```
// ...
export class CdkDemoAppStack extends cdk.Stack {
constructor(scope: Construct, id: string, props?: cdk.StackProps) {
super(scope, id, props);
// Define an S3 bucket
const myBucket = new s3.Bucket(this, 'myBucket');
// ...
// Check if bucket name is a token. If not, check if length is less than 10 characters
if (cdk.Token.isUnresolved(myBucketName)) {
console.log("Token identified.");
} else if (!cdk.Token.isUnresolved(myBucketName) && myBucketName.length > 10) {
throw new Error('Maximum length for name is 10 characters.');
};
// ...
}
}
```
```
const { Stack, Duration, Token, CfnOutput } = require('aws-cdk-lib');
// ...
class CdkDemoAppStack extends Stack {
constructor(scope, id, props) {
super(scope, id, props);
// Define an S3 bucket
const myBucket = new s3.Bucket(this, 'myBucket');
// ...
// Check if bucket name is a token. If not, check if length is less than 10 characters
if (Token.isUnresolved(myBucketName)) {
console.log("Token identified.");
} else if (!Token.isUnresolved(myBucketName) && myBucketName.length > 10) {
throw new Error('Maximum length for name is 10 characters.');
};
// ...
}
}
```
```
from aws_cdk import (
Stack,
Token
)
# ...
class CdkDemoAppStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
# Define an S3 bucket
my_bucket = s3.Bucket(self, "myBucket")
# ...
# Check if bucket name is a token. If not, check if length is less than 10 characters
if Token.is_unresolved(my_bucket_name):
print("Token identified.")
elif not Token.is_unresolved(my_bucket_name) and len(my_bucket_name) < 10:
raise ValueError("Maximum length for name is 10 characters.")
# ...
```
```
// ...
import software.amazon.awscdk.Token;
import software.amazon.awscdk.services.s3.Bucket;
// ...
public class CdkDemoAppStack extends Stack {
public CdkDemoAppStack(final Construct scope, final String id) {
this(scope, id, null);
}
public CdkDemoAppStack(final Construct scope, final String id, final StackProps props) {
super(scope, id, props);
// Define an S3 bucket
Bucket myBucket = Bucket.Builder.create(this, "myBucket")
.build();
// ...
// Get the bucket name
String myBucketName = myBucket.getBucketName();
// Check if the bucket name is a token. If not, check if length is less than 10 characters
if (Token.isUnresolved(myBucketName)) {
System.out.println("Token identified.");
} else if (!Token.isUnresolved(myBucketName) && myBucketName.length() > 10) {
throw new IllegalArgumentException("Maximum length for name is 10 characters.");
}
// ...
}
}
}
```
```
using Amazon.CDK;
using Constructs;
using Amazon.CDK.AWS.S3;
using Amazon.CDK.AWS.Lambda;
using System;
using System.Collections.Generic;
namespace CdkDemoApp
{
public class CdkDemoAppStack : Stack
{
internal CdkDemoAppStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
{
// Define an S3 bucket
var myBucket = new Bucket(this, "myBucket");
// ...
// Get the bucket name
var myBucketName = myBucket.BucketName;
// Check if bucket name is a token. If not, check if length is less than 10 characters
if (Token.IsUnresolved(myBucketName))
{
System.Console.WriteLine("Token identified.");
}
else if (!Token.IsUnresolved(myBucketName) && myBucketName.Length > 10)
{
throw new System.Exception("Maximum length for name is 10 characters.");
}
// ...
}
}
}
```
```
// ...
func NewCdkDemoAppStack(scope constructs.Construct, id string, props *CdkDemoAppStackProps) awscdk.Stack {
var sprops awscdk.StackProps
if props != nil {
sprops = props.StackProps
}
stack := awscdk.NewStack(scope, &id, &sprops)
// Define an S3 bucket
myBucket := awss3.NewBucket(stack, jsii.String("myBucket"), &awss3.BucketProps{})
// ...
// Check if the bucket name is unresolved (a token)
if tokenUnresolved := awscdk.Token_IsUnresolved(myBucketName); tokenUnresolved != nil && *tokenUnresolved {
fmt.Println("Token identified.")
} else if tokenUnresolved != nil && !*tokenUnresolved && len(*myBucketName) > 10 {
panic("Maximum length for name is 10 characters.")
}
// ...
}
```
Ketika kita menjalankan `cdk synth``myBucketName`, diidentifikasi sebagai token:
```
$ cdk synth --quiet
Token identified.
```
**catatan**
Anda dapat menggunakan pengkodean token untuk keluar dari sistem tipe. Misalnya, Anda dapat mengkodekan string token yang menghasilkan nilai angka pada waktu sintesis. Jika Anda menggunakan fungsi-fungsi ini, Anda bertanggung jawab untuk memastikan bahwa template Anda menyelesaikan ke status yang dapat digunakan setelah sintesis.
## Bekerja dengan token yang disandikan string
Token yang disandikan string terlihat seperti berikut ini.
```
${TOKEN[Bucket.Name.1234]}
```
Mereka dapat diteruskan seperti string biasa, dan dapat digabungkan, seperti yang ditunjukkan pada contoh berikut.
**Example**
```
const functionName = bucket.bucketName + 'Function';
```
```
const functionName = bucket.bucketName + 'Function';
```
```
function_name = bucket.bucket_name + "Function"
```
```
String functionName = bucket.getBucketName().concat("Function");
```
```
string functionName = bucket.BucketName + "Function";
```
```
functionName := *bucket.BucketName() + "Function"
```
Anda juga dapat menggunakan interpolasi string, jika bahasa Anda mendukungnya, seperti yang ditunjukkan pada contoh berikut.
**Example**
```
const functionName = `${bucket.bucketName}Function`;
```
```
const functionName = `${bucket.bucketName}Function`;
```
```
function_name = f"{bucket.bucket_name}Function"
```
```
String functionName = String.format("%sFunction". bucket.getBucketName());
```
```
string functionName = $"${bucket.bucketName}Function";
```
Gunakan `fmt.Sprintf` untuk fungsionalitas serupa:
```
functionName := fmt.Sprintf("%sFunction", *bucket.BucketName())
```
Hindari memanipulasi string dengan cara lain. Misalnya, mengambil substring string kemungkinan akan merusak token string.
## Bekerja dengan token yang dikodekan daftar
Token yang dikodekan daftar terlihat seperti berikut:
```
["#{TOKEN[Stack.NotificationArns.1234]}"]
```
Satu-satunya hal yang aman untuk dilakukan dengan daftar ini adalah meneruskannya langsung ke konstruksi lain. Token dalam bentuk daftar string tidak dapat digabungkan, juga elemen tidak dapat diambil dari token. Satu-satunya cara aman untuk memanipulasi mereka adalah dengan menggunakan fungsi AWS CloudFormation intrinsik seperti. [https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-select.html](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-select.html)
## Bekerja dengan token yang dikodekan angka
Token yang dikodekan angka adalah sekumpulan angka floating-point negatif kecil yang terlihat seperti berikut ini.
```
-1.8881545897087626e+289
```
Seperti halnya token daftar, Anda tidak dapat mengubah nilai angka, karena hal itu kemungkinan akan merusak token angka.
Berikut ini adalah contoh konstruksi yang berisi token yang dikodekan sebagai angka:
**Example**
```
import { Stack, Duration, StackProps } from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as rds from 'aws-cdk-lib/aws-rds';
import * as ec2 from 'aws-cdk-lib/aws-ec2';
export class CdkDemoAppStack extends Stack {
constructor(scope: Construct, id: string, props?: StackProps) {
super(scope, id, props);
// Define a new VPC
const vpc = new ec2.Vpc(this, 'MyVpc', {
maxAzs: 3, // Maximum number of availability zones to use
});
// Define an RDS database cluster
const dbCluster = new rds.DatabaseCluster(this, 'MyRDSCluster', {
engine: rds.DatabaseClusterEngine.AURORA,
instanceProps: {
vpc,
},
});
// Get the port token (this is a token encoded as a number)
const portToken = dbCluster.clusterEndpoint.port;
// Print the value for our token at synthesis
console.log("portToken: " + portToken);
}
}
```
```
const { Stack, Duration } = require('aws-cdk-lib');
const lambda = require('aws-cdk-lib/aws-lambda');
const rds = require('aws-cdk-lib/aws-rds');
const ec2 = require('aws-cdk-lib/aws-ec2');
class CdkDemoAppStack extends Stack {
constructor(scope, id, props) {
super(scope, id, props);
// Define a new VPC
const vpc = new ec2.Vpc(this, 'MyVpc', {
maxAzs: 3, // Maximum number of availability zones to use
});
// Define an RDS database cluster
const dbCluster = new rds.DatabaseCluster(this, 'MyRDSCluster', {
engine: rds.DatabaseClusterEngine.AURORA,
instanceProps: {
vpc,
},
});
// Get the port token (this is a token encoded as a number)
const portToken = dbCluster.clusterEndpoint.port;
// Print the value for our token at synthesis
console.log("portToken: " + portToken);
}
}
module.exports = { CdkDemoAppStack }
```
```
from aws_cdk import (
Duration,
Stack,
)
from aws_cdk import aws_rds as rds
from aws_cdk import aws_ec2 as ec2
from constructs import Construct
class CdkDemoAppStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
# Define a new VPC
vpc = ec2.Vpc(self, 'MyVpc',
max_azs=3 # Maximum number of availability zones to use
)
# Define an RDS database cluster
db_cluster = rds.DatabaseCluster(self, 'MyRDSCluster',
engine=rds.DatabaseClusterEngine.AURORA,
instance_props=rds.InstanceProps(
vpc=vpc
)
)
# Get the port token (this is a token encoded as a number)
port_token = db_cluster.cluster_endpoint.port
# Print the value for our token at synthesis
print(f"portToken: {port_token}")
```
```
package com.myorg;
import software.constructs.Construct;
import software.amazon.awscdk.Stack;
import software.amazon.awscdk.StackProps;
import software.amazon.awscdk.services.ec2.Vpc;
import software.amazon.awscdk.services.rds.DatabaseCluster;
import software.amazon.awscdk.services.rds.DatabaseClusterEngine;
import software.amazon.awscdk.services.rds.InstanceProps;
public class CdkDemoAppStack extends Stack {
public CdkDemoAppStack(final Construct scope, final String id) {
this(scope, id, null);
}
public CdkDemoAppStack(final Construct scope, final String id, final StackProps props) {
super(scope, id, props);
// Define a new VPC
Vpc vpc = Vpc.Builder.create(this, "MyVpc")
.maxAzs(3) // Maximum number of availability zones to use
.build();
// Define an RDS database cluster
DatabaseCluster dbCluster = DatabaseCluster.Builder.create(this, "MyRDSCluster")
.engine(DatabaseClusterEngine.AURORA)
.instanceProps(InstanceProps.builder()
.vpc(vpc)
.build())
.build();
// Get the port token (this is a token encoded as a number)
Number portToken = dbCluster.getClusterEndpoint().getPort();
// Print the value for our token at synthesis
System.out.println("portToken: " + portToken);
}
}
```
```
using Amazon.CDK;
using Constructs;
using Amazon.CDK.AWS.EC2;
using Amazon.CDK.AWS.RDS;
using System;
using System.Collections.Generic;
namespace CdkDemoApp
{
public class CdkDemoAppStack : Stack
{
internal CdkDemoAppStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
{
// Define a new VPC
var vpc = new Vpc(this, "MyVpc", new VpcProps
{
MaxAzs = 3 // Maximum number of availability zones to use
});
// Define an RDS database cluster
var dbCluster = new DatabaseCluster(this, "MyRDSCluster", new DatabaseClusterProps
{
Engine = DatabaseClusterEngine.AURORA, // Remove parentheses
InstanceProps = new Amazon.CDK.AWS.RDS.InstanceProps // Specify RDS InstanceProps
{
Vpc = vpc
}
});
// Get the port token (this is a token encoded as a number)
var portToken = dbCluster.ClusterEndpoint.Port;
// Print the value for our token at synthesis
System.Console.WriteLine($"portToken: {portToken}");
}
}
}
```
```
package main
import (
"fmt"
"github.com/aws/aws-cdk-go/awscdk/v2"
"github.com/aws/aws-cdk-go/awscdk/v2/awsec2"
"github.com/aws/aws-cdk-go/awscdk/v2/awsrds"
"github.com/aws/constructs-go/constructs/v10"
"github.com/aws/jsii-runtime-go"
)
type CdkDemoAppStackProps struct {
awscdk.StackProps
}
func NewCdkDemoAppStack(scope constructs.Construct, id string, props *CdkDemoAppStackProps) awscdk.Stack {
var sprops awscdk.StackProps
if props != nil {
sprops = props.StackProps
}
stack := awscdk.NewStack(scope, &id, &sprops)
// Define a new VPC
vpc := awsec2.NewVpc(stack, jsii.String("MyVpc"), &awsec2.VpcProps{
MaxAzs: jsii.Number(3), // Maximum number of availability zones to use
})
// Define an RDS database cluster
dbCluster := awsrds.NewDatabaseCluster(stack, jsii.String("MyRDSCluster"), &awsrds.DatabaseClusterProps{
Engine: awsrds.DatabaseClusterEngine_AURORA(),
InstanceProps: &awsrds.InstanceProps{
Vpc: vpc,
},
})
// Get the port token (this is a token encoded as a number)
portToken := dbCluster.ClusterEndpoint().Port()
// Print the value for our token at synthesis
fmt.Println("portToken: ", portToken)
return stack
}
// ...
```
Saat kita menjalankan`cdk synth`, nilai untuk ditampilkan sebagai token yang `portToken` dikodekan angka:
```
$ cdk synth --quiet
portToken: -1.8881545897087968e+289
```
### Lulus token yang dikodekan nomor
Saat Anda meneruskan token yang dikodekan angka ke konstruksi lain, mungkin masuk akal untuk mengonversinya menjadi string terlebih dahulu. Misalnya, jika Anda ingin menggunakan nilai string yang dikodekan angka sebagai bagian dari string gabungan, mengonversinya membantu keterbacaan.
Dalam contoh berikut, `portToken` adalah token yang dikodekan angka yang ingin kita teruskan ke fungsi Lambda kita sebagai bagian dari: `connectionString`
**Example**
```
import { Stack, Duration, CfnOutput, StackProps } from 'aws-cdk-lib';
// ...
import * as lambda from 'aws-cdk-lib/aws-lambda';
export class CdkDemoAppStack extends Stack {
constructor(scope: Construct, id: string, props?: StackProps) {
super(scope, id, props);
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
const portToken = dbCluster.clusterEndpoint.port;
// ...
// Example connection string with the port token as a number
const connectionString = `jdbc:mysql://mydb.cluster.amazonaws.com:${portToken}/mydatabase`;
// Use the connection string as an environment variable in a Lambda function
const myFunction = new lambda.Function(this, 'MyLambdaFunction', {
runtime: lambda.Runtime.NODEJS_20_X,
handler: 'index.handler',
code: lambda.Code.fromInline(`
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
`),
environment: {
DATABASE_CONNECTION_STRING: connectionString, // Using the port token as part of the string
},
});
// Output the value of our connection string at synthesis
console.log("connectionString: " + connectionString);
// Output the connection string
new CfnOutput(this, 'ConnectionString', {
value: connectionString,
});
}
}
```
```
const { Stack, Duration, CfnOutput } = require('aws-cdk-lib');
// ...
const lambda = require('aws-cdk-lib/aws-lambda');
class CdkDemoAppStack extends Stack {
constructor(scope, id, props) {
super(scope, id, props);
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
const portToken = dbCluster.clusterEndpoint.port;
// ...
// Example connection string with the port token as a number
const connectionString = `jdbc:mysql://mydb.cluster.amazonaws.com:${portToken}/mydatabase`;
// Use the connection string as an environment variable in a Lambda function
const myFunction = new lambda.Function(this, 'MyLambdaFunction', {
runtime: lambda.Runtime.NODEJS_20_X,
handler: 'index.handler',
code: lambda.Code.fromInline(`
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
`),
environment: {
DATABASE_CONNECTION_STRING: connectionString, // Using the port token as part of the string
},
});
// Output the value of our connection string at synthesis
console.log("connectionString: " + connectionString);
// Output the connection string
new CfnOutput(this, 'ConnectionString', {
value: connectionString,
});
}
}
module.exports = { CdkDemoAppStack }
```
```
from aws_cdk import (
Duration,
Stack,
CfnOutput,
)
from aws_cdk import aws_lambda as _lambda
# ...
class CdkDemoAppStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
# Define a new VPC
# ...
# Define an RDS database cluster
# ...
# Get the port token (this is a token encoded as a number)
port_token = db_cluster.cluster_endpoint.port
# ...
# Example connection string with the port token as a number
connection_string = f"jdbc:mysql://mydb.cluster.amazonaws.com:{port_token}/mydatabase"
# Use the connection string as an environment variable in a Lambda function
my_function = _lambda.Function(self, 'MyLambdaFunction',
runtime=_lambda.Runtime.NODEJS_20_X,
handler='index.handler',
code=_lambda.Code.from_inline("""
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
"""),
environment={
'DATABASE_CONNECTION_STRING': connection_string # Using the port token as part of the string
}
)
# Output the value of our connection string at synthesis
print(f"connectionString: {connection_string}")
# Output the connection string
CfnOutput(self, 'ConnectionString',
value=connection_string
)
```
```
// ...
import software.amazon.awscdk.CfnOutput;
import software.amazon.awscdk.services.lambda.Function;
import software.amazon.awscdk.services.lambda.Runtime;
import software.amazon.awscdk.services.lambda.Code;
import java.util.Map;
public class CdkDemoAppStack extends Stack {
public CdkDemoAppStack(final Construct scope, final String id) {
this(scope, id, null);
}
public CdkDemoAppStack(final Construct scope, final String id, final StackProps props) {
super(scope, id, props);
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
Number portToken = dbCluster.getClusterEndpoint().getPort();
// ...
// Example connection string with the port token as a number
String connectionString = "jdbc:mysql://mydb.cluster.amazonaws.com:" + portToken + "/mydatabase";
// Use the connection string as an environment variable in a Lambda function
Function myFunction = Function.Builder.create(this, "MyLambdaFunction")
.runtime(Runtime.NODEJS_20_X)
.handler("index.handler")
.code(Code.fromInline(
"exports.handler = async function(event) {\n" +
" return {\n" +
" statusCode: 200,\n" +
" body: JSON.stringify('Hello World!'),\n" +
" };\n" +
"};"))
.environment(Map.of(
"DATABASE_CONNECTION_STRING", connectionString // Using the port token as part of the string
))
.build();
// Output the value of our connection string at synthesis
System.out.println("connectionString: " + connectionString);
// Output the connection string
CfnOutput.Builder.create(this, "ConnectionString")
.value(connectionString)
.build();
}
}
```
```
// ...
using Amazon.CDK.AWS.Lambda;
using Amazon.CDK.AWS.RDS;
using Amazon.CDK;
using Constructs;
using System;
using System.Collections.Generic;
namespace CdkDemoApp
{
public class CdkDemoAppStack : Stack
{
internal CdkDemoAppStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
{
// Define a new VPC
// ...
// Define an RDS database cluster
var dbCluster = new DatabaseCluster(this, "MyRDSCluster", new DatabaseClusterProps
{
// ... properties would go here
});
// Get the port token (this is a token encoded as a number)
var portToken = dbCluster.ClusterEndpoint.Port;
// ...
// Example connection string with the port token as a number
var connectionString = $"jdbc:mysql://mydb.cluster.amazonaws.com:{portToken}/mydatabase";
// Use the connection string as an environment variable in a Lambda function
var myFunction = new Function(this, "MyLambdaFunction", new FunctionProps
{
Runtime = Runtime.NODEJS_20_X,
Handler = "index.handler",
Code = Code.FromInline(@"
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
"),
Environment = new Dictionary
{
{ "DATABASE_CONNECTION_STRING", connectionString } // Using the port token as part of the string
}
});
// Output the value of our connection string at synthesis
Console.WriteLine($"connectionString: {connectionString}");
// Output the connection string
new CfnOutput(this, "ConnectionString", new CfnOutputProps
{
Value = connectionString
});
}
}
}
```
```
// ...
"github.com/aws/aws-cdk-go/awscdk/v2/awslambda"
)
type CdkDemoAppStackProps struct {
awscdk.StackProps
}
func NewCdkDemoAppStack(scope constructs.Construct, id string, props *CdkDemoAppStackProps) awscdk.Stack {
var sprops awscdk.StackProps
if props != nil {
sprops = props.StackProps
}
stack := awscdk.NewStack(scope, &id, &sprops)
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
portToken := dbCluster.ClusterEndpoint().Port()
// ...
// Example connection string with the port token as a number
connectionString := fmt.Sprintf("jdbc:mysql://mydb.cluster.amazonaws.com:%s/mydatabase", portToken)
// Use the connection string as an environment variable in a Lambda function
myFunction := awslambda.NewFunction(stack, jsii.String("MyLambdaFunction"), &awslambda.FunctionProps{
Runtime: awslambda.Runtime_NODEJS_20_X(),
Handler: jsii.String("index.handler"),
Code: awslambda.Code_FromInline(jsii.String(`
exports.handler = async function(event) {
return {
statusCode: 200,
body: JSON.stringify('Hello World!'),
};
};
`)),
Environment: &map[string]*string{
"DATABASE_CONNECTION_STRING": jsii.String(connectionString), // Using the port token as part of the string
},
})
// Output the value of our connection string at synthesis
fmt.Println("connectionString: ", connectionString)
// Output the connection string
awscdk.NewCfnOutput(stack, jsii.String("ConnectionString"), &awscdk.CfnOutputProps{
Value: jsii.String(connectionString),
})
return stack
}
// ...
```
Jika kita meneruskan nilai ini`connectionString`, nilai output saat kita menjalankan `cdk synth` mungkin membingungkan karena string yang dikodekan angka:
```
$ cdk synth --quiet
connectionString: jdbc:mysql://mydb.cluster.amazonaws.com:-1.888154589708796e+289/mydatabase
```
Untuk mengonversi token yang dikodekan angka menjadi string, gunakan. [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Tokenization.html#static-stringifywbrnumberx](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Tokenization.html#static-stringifywbrnumberx) Dalam contoh berikut, kita mengubah token yang dikodekan angka menjadi string sebelum mendefinisikan string koneksi kita:
**Example**
```
import { Stack, Duration, Tokenization, CfnOutput, StackProps } from 'aws-cdk-lib';
// ...
export class CdkDemoAppStack extends Stack {
constructor(scope: Construct, id: string, props?: StackProps) {
super(scope, id, props);
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
const portToken = dbCluster.clusterEndpoint.port;
// ...
// Convert the encoded number to an encoded string for use in the connection string
const portAsString = Tokenization.stringifyNumber(portToken);
// Example connection string with the port token as a string
const connectionString = `jdbc:mysql://mydb.cluster.amazonaws.com:${portAsString}/mydatabase`;
// Use the connection string as an environment variable in a Lambda function
const myFunction = new lambda.Function(this, 'MyLambdaFunction', {
// ...
environment: {
DATABASE_CONNECTION_STRING: connectionString, // Using the port token as part of the string
},
});
// Output the value of our connection string at synthesis
console.log("connectionString: " + connectionString);
// Output the connection string
new CfnOutput(this, 'ConnectionString', {
value: connectionString,
});
}
}
```
```
const { Stack, Duration, Tokenization, CfnOutput } = require('aws-cdk-lib');
// ...
class CdkDemoAppStack extends Stack {
constructor(scope, id, props) {
super(scope, id, props);
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
const portToken = dbCluster.clusterEndpoint.port;
// ...
// Convert the encoded number to an encoded string for use in the connection string
const portAsString = Tokenization.stringifyNumber(portToken);
// Example connection string with the port token as a string
const connectionString = `jdbc:mysql://mydb.cluster.amazonaws.com:${portAsString}/mydatabase`;
// Use the connection string as an environment variable in a Lambda function
const myFunction = new lambda.Function(this, 'MyLambdaFunction', {
// ...
environment: {
DATABASE_CONNECTION_STRING: connectionString, // Using the port token as part of the string
},
});
// Output the value of our connection string at synthesis
console.log("connectionString: " + connectionString);
// Output the connection string
new CfnOutput(this, 'ConnectionString', {
value: connectionString,
});
}
}
module.exports = { CdkDemoAppStack }
```
```
from aws_cdk import (
Duration,
Stack,
Tokenization,
CfnOutput,
)
# ...
class CdkDemoAppStack(Stack):
def __init__(self, scope: Construct, construct_id: str, **kwargs) -> None:
super().__init__(scope, construct_id, **kwargs)
# Define a new VPC
# ...
# Define an RDS database cluster
# ...
# Get the port token (this is a token encoded as a number)
port_token = db_cluster.cluster_endpoint.port
# Convert the encoded number to an encoded string for use in the connection string
port_as_string = Tokenization.stringify_number(port_token)
# Example connection string with the port token as a string
connection_string = f"jdbc:mysql://mydb.cluster.amazonaws.com:{port_as_string}/mydatabase"
# Use the connection string as an environment variable in a Lambda function
my_function = _lambda.Function(self, 'MyLambdaFunction',
# ...
environment={
'DATABASE_CONNECTION_STRING': connection_string # Using the port token as part of the string
}
)
# Output the value of our connection string at synthesis
print(f"connectionString: {connection_string}")
# Output the connection string
CfnOutput(self, 'ConnectionString',
value=connection_string
)
```
```
// ...
import software.amazon.awscdk.Tokenization;
public class CdkDemoAppStack extends Stack {
public CdkDemoAppStack(final Construct scope, final String id) {
this(scope, id, null);
}
public CdkDemoAppStack(final Construct scope, final String id, final StackProps props) {
super(scope, id, props);
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
Number portToken = dbCluster.getClusterEndpoint().getPort();
// ...
// Convert the encoded number to an encoded string for use in the connection string
String portAsString = Tokenization.stringifyNumber(portToken);
// Example connection string with the port token as a string
String connectionString = "jdbc:mysql://mydb.cluster.amazonaws.com:" + portAsString + "/mydatabase";
// Use the connection string as an environment variable in a Lambda function
Function myFunction = Function.Builder.create(this, "MyLambdaFunction")
// ...
.environment(Map.of(
"DATABASE_CONNECTION_STRING", connectionString // Using the port token as part of the string
))
.build();
// Output the value of our connection string at synthesis
System.out.println("connectionString: " + connectionString);
// Output the connection string
CfnOutput.Builder.create(this, "ConnectionString")
.value(connectionString)
.build();
}
}
```
```
// ...
namespace CdkDemoApp
{
public class CdkDemoAppStack : Stack
{
internal CdkDemoAppStack(Construct scope, string id, IStackProps props = null) : base(scope, id, props)
{
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
var portToken = dbCluster.ClusterEndpoint.Port;
// ...
// Convert the encoded number to an encoded string for use in the connection string
var portAsString = Tokenization.StringifyNumber(portToken);
// Example connection string with the port token as a string
var connectionString = $"jdbc:mysql://mydb.cluster.amazonaws.com:{portAsString}/mydatabase";
// Use the connection string as an environment variable in a Lambda function
var myFunction = new Function(this, "MyLambdaFunction", new FunctionProps
{
// ...
Environment = new Dictionary
{
{ "DATABASE_CONNECTION_STRING", connectionString } // Using the port token as part of the string
}
});
// Output the value of our connection string at synthesis
Console.WriteLine($"connectionString: {connectionString}");
// Output the connection string
new CfnOutput(this, "ConnectionString", new CfnOutputProps
{
Value = connectionString
});
}
}
}
```
```
// ...
func NewCdkDemoAppStack(scope constructs.Construct, id string, props *CdkDemoAppStackProps) awscdk.Stack {
var sprops awscdk.StackProps
if props != nil {
sprops = props.StackProps
}
stack := awscdk.NewStack(scope, &id, &sprops)
// Define a new VPC
// ...
// Define an RDS database cluster
// ...
// Get the port token (this is a token encoded as a number)
portToken := dbCluster.ClusterEndpoint().Port()
// ...
// Convert the encoded number to an encoded string for use in the connection string
portAsString := awscdk.Tokenization_StringifyNumber(portToken)
// Example connection string with the port token as a string
connectionString := fmt.Sprintf("jdbc:mysql://mydb.cluster.amazonaws.com:%s/mydatabase", portAsString)
// Use the connection string as an environment variable in a Lambda function
myFunction := awslambda.NewFunction(stack, jsii.String("MyLambdaFunction"), &awslambda.FunctionProps{
// ...
Environment: &map[string]*string{
"DATABASE_CONNECTION_STRING": jsii.String(connectionString), // Using the port token as part of the string
},
})
// Output the value of our connection string at synthesis
fmt.Println("connectionString: ", connectionString)
// Output the connection string
awscdk.NewCfnOutput(stack, jsii.String("ConnectionString"), &awscdk.CfnOutputProps{
Value: jsii.String(connectionString),
})
fmt.Println(myFunction)
return stack
}
// ...
```
Saat kami menjalankan`cdk synth`, nilai untuk string koneksi kami direpresentasikan dalam format yang lebih bersih dan lebih jelas:
```
$ cdk synth --quiet
connectionString: jdbc:mysql://mydb.cluster.amazonaws.com:${Token[TOKEN.242]}/mydatabase
```
## Nilai malas
Selain mewakili nilai deploy-time, seperti AWS CloudFormation [parameter](parameters.md), token juga biasa digunakan untuk mewakili nilai malas waktu sintesis. Ini adalah nilai yang nilai akhirnya akan ditentukan sebelum sintesis selesai, tetapi tidak pada titik di mana nilai dibangun. Gunakan token untuk meneruskan string literal atau nilai angka ke konstruksi lain, sedangkan nilai aktual pada waktu sintesis mungkin bergantung pada beberapa perhitungan yang belum terjadi.
Anda dapat membuat token yang mewakili nilai malas synth-time menggunakan metode statis pada `Lazy` kelas, seperti dan. [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Lazy.html#static-stringproducer-options](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Lazy.html#static-stringproducer-options) Metode ini menerima objek yang `produce` propertinya adalah fungsi yang menerima argumen konteks dan mengembalikan nilai akhir ketika dipanggil.
Contoh berikut membuat grup Auto Scaling yang kapasitasnya ditentukan setelah pembuatannya.
**Example**
```
let actualValue: number;
new AutoScalingGroup(this, 'Group', {
desiredCapacity: Lazy.numberValue({
produce(context) {
return actualValue;
}
})
});
// At some later point
actualValue = 10;
```
```
let actualValue;
new AutoScalingGroup(this, 'Group', {
desiredCapacity: Lazy.numberValue({
produce(context) {
return (actualValue);
}
})
});
// At some later point
actualValue = 10;
```
```
class Producer:
def __init__(self, func):
self.produce = func
actual_value = None
AutoScalingGroup(self, "Group",
desired_capacity=Lazy.number_value(Producer(lambda context: actual_value))
)
# At some later point
actual_value = 10
```
```
double actualValue = 0;
class ProduceActualValue implements INumberProducer {
@Override
public Number produce(IResolveContext context) {
return actualValue;
}
}
AutoScalingGroup.Builder.create(this, "Group")
.desiredCapacity(Lazy.numberValue(new ProduceActualValue())).build();
// At some later point
actualValue = 10;
```
```
public class NumberProducer : INumberProducer
{
Func function;
public NumberProducer(Func function)
{
this.function = function;
}
public Double Produce(IResolveContext context)
{
return function();
}
}
double actualValue = 0;
new AutoScalingGroup(this, "Group", new AutoScalingGroupProps
{
DesiredCapacity = Lazy.NumberValue(new NumberProducer(() => actualValue))
});
// At some later point
actualValue = 10;
```
## Konversi ke JSON
Terkadang Anda ingin menghasilkan string JSON dari data arbitrer, dan Anda mungkin tidak tahu apakah data tersebut berisi token. Untuk mengkodekan struktur data dengan benar JSON, terlepas dari apakah itu berisi token, gunakan metode ini [https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Stack.html#towbrjsonwbrstringobj-space](https://docs.aws.amazon.com/cdk/api/v2/docs/aws-cdk-lib.Stack.html#towbrjsonwbrstringobj-space), seperti yang ditunjukkan pada contoh berikut.
**Example**
```
const stack = Stack.of(this);
const str = stack.toJsonString({
value: bucket.bucketName
});
```
```
const stack = Stack.of(this);
const str = stack.toJsonString({
value: bucket.bucketName
});
```
```
stack = Stack.of(self)
string = stack.to_json_string(dict(value=bucket.bucket_name))
```
```
Stack stack = Stack.of(this);
String stringVal = stack.toJsonString(java.util.Map.of( // Map.of requires Java 9+
put("value", bucket.getBucketName())));
```
```
var stack = Stack.Of(this);
var stringVal = stack.ToJsonString(new Dictionary
{
["value"] = bucket.BucketName
});
```