java编程进行动态编译加载代码分享

class DynamicReactor://空参构造 public Class<?> dynamicCompile(String srcPath);//输入一个指定的源文件路径，若编译、拷贝成功则返回该类对应的Class类实例 private String changePacketToDic(String packageName);//将一个合法的包名转换为对应JavaClassPath中的路径（我是用的是eclipse 所以需要对应地增加bin这一目录，若使用其他不同编译器，请参考对应的运行上下文设置进行适当修改） private String getPackage(String srcPath);//由一个合法的java文件路径尝试获得其包名 

import java.io.BufferedReader;import java.io.File;import java.io.FileReader;import java.io.IOException;import java.nio.file.Files;import java.nio.file.Path;import java.nio.file.Paths;import java.nio.file.StandardCopyOption;import java.util.regex.Matcher;import java.util.regex.Pattern;import javax.tools.JavaCompiler;import javax.tools.ToolProvider;/**  * DynamicReactor 一个动态编译模块，负责编译源文件，复制到对应包下及加载类等过程(JDK 1.7)  * @author 三向板砖  * */public class DynamicReactor {	JavaCompiler compiler;	Pattern packagePattern;	static final String regEx = "(?<=package//s).*(?=;)";	public DynamicReactor() 	  {		compiler = ToolProvider.getSystemJavaCompiler();		packagePattern = Pattern.compile(regEx);	}	/**    * 动态编译给定源文件    * @param srcPath 源文件路径    * @return Class    *   <br>若成功返回对应类的Class实例    *   <br>若失败返回null    * */	public Class<?> dynamicCompile(String srcPath) 	  {		Class<?> result = null;		//获得给定路径源文件的 		String packName = getPackage(srcPath);		if(packName == null) 		    {			System.out.println("DynamicRector:Load packageName Error!");			return null;		}		//调用compiler编译指定源文件 		int res = compiler.run(null, null, null,srcPath);		if(res != 0) 		    {			System.out.println("DynamicRector:Compile Java Source Error!");			return null;		}		//获得包名对应的路径，若路径不存在则创建，若指定class文件存在则覆盖 		String packageDst = changePacketToDic(packName);		File dstDir = new File(packageDst);		if(!dstDir.exists()) 		    {			dstDir.mkdirs();		}		Path pathFrom = Paths.get(srcPath.split("//.java")[0] + ".class");		Path pathTo = Paths.get(packageDst,pathFrom.getFileName().toString());		try {			Files.move(pathFrom, pathTo, StandardCopyOption.REPLACE_EXISTING);		}		catch (IOException e) {			System.out.println("DynamicRector:Move File Fail!");			e.printStackTrace();		}		try {			result = Class.forName(packName+"."+pathFrom.getFileName().toString().split("//.class")[0]);		}		catch (ClassNotFoundException e) {			System.out.println("DynamicRector:Class Not found in Final!");		}		return result;	}	//该方法将一个合法包名转化为对应路径 	private String changePacketToDic(String packageName) 	  {		String[] dirs = packageName.split("//.");		String res = ".//bin";		for (int i = 0;i < dirs.length;i++) 		    {			res += "//"+dirs[i];		}		return res;	}	//该方法从给定的路径源文件中获得包名 	private String getPackage(String srcPath) 	  {		String result = null;		BufferedReader br;		try {			br = new BufferedReader(new FileReader(srcPath));			String data = br.readLine();			while(data != null) 			      {				if(data.indexOf("package") != -1) 				        {					Matcher m = packagePattern.matcher(data);					if(m.find()) 					          {						result = m.group();					}					break;				}				data = br.readLine();			}			br.close();		}		catch (IOException e) {			System.out.println("DynamicRector:Error in open file "+srcPath);		}		return result;	}}