Javapoet: CodeBlock: Named arguments

Use the syntax $argumentName:X where X is the format character and call CodeBlock.addNamed() with a map containing all argument keys in the format string. Argument names use characters in a-z, A-Z, 0-9, and _, and must start with a lowercase character.

 

Example

Map<String, Object> map = new HashMap<>();
map.put("name", "Krishna");
map.put("age", 32);

Builder codeBlock1 = CodeBlock.builder().addNamed("Hi, my name is $name:L and I am $age:L years old", map);

Above snippet generates below string.

Hi, my name is Krishna and I am 32 years old

 

Find the below working application.

 

CodeBlockNamedArgumentsDemo.java

 

package com.sample.app;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.lang.model.element.Modifier;

import com.squareup.javapoet.CodeBlock;
import com.squareup.javapoet.JavaFile;
import com.squareup.javapoet.MethodSpec;
import com.squareup.javapoet.TypeSpec;
import com.squareup.javapoet.CodeBlock.Builder;

public class CodeBlockNamedArgumentsDemo {

    public static void main(String args[]) throws IOException {

        MethodSpec.Builder methodBuilder = MethodSpec.methodBuilder("main");
        methodBuilder.addModifiers(Modifier.PUBLIC, Modifier.STATIC);
        methodBuilder.returns(void.class);
        methodBuilder.addParameter(String[].class, "args");

        Map<String, Object> map = new HashMap<>();
        map.put("name", "Krishna");
        map.put("age", 32);

        Builder codeBlock1 = CodeBlock.builder().addNamed("Hi, my name is $name:L and I am $age:L years old", map);

        methodBuilder.addStatement("$T.out.println($S)", System.class, codeBlock1.build().toString());
        MethodSpec mainMethod = methodBuilder.build();

        String className = "Test";
        TypeSpec.Builder classBuilder = TypeSpec.classBuilder(className);
        classBuilder.addModifiers(Modifier.PUBLIC, Modifier.FINAL);
        classBuilder.addMethod(mainMethod);
        TypeSpec helloWorldTypeSpec = classBuilder.build();

        String packageName = "com.sample.app";
        JavaFile javaFile = JavaFile.builder(packageName, helloWorldTypeSpec).build();

        javaFile.writeTo(System.out);
    }

}

Generated code

package com.sample.app;

import java.lang.String;
import java.lang.System;

public final class Test {
  public static void main(String[] args) {
    System.out.println("Hi, my name is Krishna and I am 32 years old");
  }
}

 

 

 

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