今天看到这个http://www.infoq.com/cn/articles/cf-java-byte-code
想试一试,但是编译通过之后的,想执行结果那,总是不成功。现在将代码贴上,望大神指点!
[code="java"]
package com.deep.byteOpera;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Arrays;
import javax.tools.JavaCompiler;
import javax.tools.JavaCompiler.CompilationTask;
import javax.tools.JavaFileObject;
import javax.tools.SimpleJavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
public class CompilerTest {
static class StringSourceJavaObject extends SimpleJavaFileObject {
private String content = null;
public StringSourceJavaObject(String name, String content) throws URISyntaxException {
super(URI.create("string:///" + name.replace('.','/') + Kind.SOURCE.extension), Kind.SOURCE);
this.content = content;
}
public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
return content;
}
}
public static void main(String[] args) throws Exception {
String className = "MainTest";
String methodName = "main";
String source = "public class "+className+" { public static String "+methodName+" () { System.out.println(\"Hello World!\"); return \"haha\";} }";
JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
//动态编译
StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);
StringSourceJavaObject sourceObject = new CompilerTest.StringSourceJavaObject(className, source);
Iterable<? extends JavaFileObject> fileObjects = Arrays.asList(sourceObject);
CompilationTask task = compiler.getTask(null, fileManager, null, null, null, fileObjects);
boolean result = task.call();
System.out.println(result);
if (result) {
//编译成功,进行加载执行
// ClassLoader loader = fileManager.getClass().getClassLoader();
// ClassLoader loader = fileObjects.getClass().getClassLoader();
// ClassLoader loader = task.getClass().getClassLoader();
// ClassLoader loader = compiler.getClass().getClassLoader();
ClassLoader loader = CompilerTest.class.getClassLoader();
// ClassLoader loader = ToolProvider.getSystemToolClassLoader();
try {
Class<?> clazz = loader.loadClass(className);
Method method = clazz.getMethod(methodName, new Class<?>[] {});
Object value = method.invoke(null, new Object[] {});
System.out.println(value);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
[/code]