java 远程编译代码

package test;

import java.io.*;

/**
 * 动态执行一段代码(生成文件->编译->执行)
 * 
 * @author kingfish
 * @version 1.0
 */
public class TestRun {
	private String fileName = "Test.java";

	private String className = "Test.class";

	public TestRun() {
		File f = new File(fileName);
		if (f.exists())
			f.delete();

		f = new File(className);
		if (f.exists())
			f.delete();
	}

	/**
	 * 创建java文件
	 */
	public void createJavaFile(String body) {
		String head = "public class Test{\r\n  public static void runCode(){";

		String end = "\r\n  }\r\n}";
		try {
			DataOutputStream dos = new DataOutputStream(new FileOutputStream(
					fileName));
			dos.writeBytes(head);
			dos.writeBytes(body);
			dos.writeBytes(end);
			dos.close();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 编译
	 */
	public int makeJavaFile() {
		int ret = 0;
		try {
			Runtime rt = Runtime.getRuntime();
			Process ps = rt.exec("cmd /c javac " + fileName);
			ps.waitFor();
			byte[] out = new byte[1024];
			DataInputStream dos = new DataInputStream(ps.getInputStream());
			dos.read(out);
			String s = new String(out);
			if (s.indexOf("Exception") > 0) {
				ret = -1;
			}
		} catch (Exception e) {
			ret = -1;
			e.printStackTrace();
		}
		return ret;
	}

	/**
	 * 反射执行
	 */
	public void run() {
		try {
			Class.forName("Test").getMethod("runCode", new Class[] {}).invoke(
					null, new Object[] {});
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	/**
	 * 测试
	 */
	public static void main(String[] args) {
		System.out.println();
		String cmd = "System.out.println(\"usage:java TestRun int i=1; System.out.println(i+100);\");";
		if (args.length >= 1) {
			cmd = args[0];
		}
		TestRun t = new TestRun();
		t.createJavaFile(cmd);
		if (t.makeJavaFile() == 0) {
			t.run();
		}
	}
}