JavaCompiler使用例子

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;
}
}