Javapoet: Add initiaizer block

'addInitializerBlock' method is used to add initializer block to the java file.

 

Find the below working application.

 

InitializerBlockDemo.java

package com.sample.app;

import java.io.IOException;

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;

public class InitializerBlockDemo {

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

		MethodSpec mainMethod = MethodSpec.methodBuilder("main").addModifiers(Modifier.PUBLIC, Modifier.STATIC)
				.returns(void.class).addParameter(String[].class, "args").addStatement("Test obj = new Test()").build();

		TypeSpec classSpec = TypeSpec.classBuilder("Test")
				.addInitializerBlock(
						CodeBlock.builder().add("$T.out.println($S);\n", System.class, "In initializer block").build())
				.addModifiers(Modifier.PUBLIC, Modifier.FINAL).addMethod(mainMethod).build();

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

		javaFile.writeTo(System.out);
	}

}

 

Generated Code

package com.sample.app;

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

public final class Test {
  {
    System.out.println("In initializer block");
  }

  public static void main(String[] args) {
    Test obj = new Test();
  }
}

 

 

 

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