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package com.test;

import java.io.IOException; import java.lang.reflect.Method; import java.net.URI; import java.util.Arrays;

import javax.tools.JavaCompiler; import javax.tools.JavaFileObject; import javax.tools.SimpleJavaFileObject; import javax.tools.StandardJavaFileManager; import javax.tools.ToolProvider;

public class CompileString { public static void main(String[] args) throws Exception { JavaCompiler compiler = ToolProvider.getSystemJavaCompiler(); System.out.println(“”+ToolProvider.getSystemJavaCompiler()); StandardJavaFileManager fileManager = compiler.getStandardFileManager( null, null, null);

StringObject so = new StringObject( “CalculatorTest”, “class CalculatorTest {” + ” public int multiply(int multiplicand, int multiplier) {” + ” System.out.println(multiplicand);” + ” System.out.println(multiplier);” + ” return multiplicand * multiplier;” + ” }” + “}”);

JavaFileObject file = so;

Iterable files = Arrays.asList(file); JavaCompiler.CompilationTask task = compiler.getTask(null, fileManager, null, null, null, files);

Boolean result = task.call(); System.out.println(result); if (result) { Class clazz = Class.forName(“CalculatorTest”);

Object instance = clazz.newInstance();

Method m = clazz.getMethod(“multiply”, new Class[] { int.class, int.class });

Object[] o = new Object[] { 3, 2 }; System.out.println(m.invoke(instance, o)); } } }

class StringObject extends SimpleJavaFileObject { private String contents = null;

public StringObject(String className, String contents) throws Exception { super(URI.create(“string:///” + className.replace(‘.’, ‘/’) + Kind.SOURCE.extension), Kind.SOURCE); this.contents = contents; }

public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException { return contents; } }

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