java动态编译 ，写了一个jsp在页面上编辑java代码，然后servlet动态编译并执行main方法

package com.test.dynamic_compile; import java.io.File; import java.net.URL; import java.net.URLClassLoader; import java.util.ArrayList; import java.util.Arrays; import java.util.List; import javax.tools.JavaCompiler; import javax.tools.JavaFileObject; import javax.tools.ToolProvider; import javax.tools.JavaCompiler.CompilationTask; public class MyClassLoader { private static URLClassLoader classLoader =null; private MyClassLoader(){} public static synchronized URLClassLoader getUrlClassLoader(){ // if(classLoader == null){ try { File libDir = new File(GlobalProperties.DYNAMIC_CLASS_PATH+"lib"); File classDir = new File(GlobalProperties.DYNAMIC_CLASS_PATH+File.separator+"classes"); libDir.mkdirs(); classDir.mkdirs(); File projectLibDir = new File(GlobalProperties.PROJECT_PATH+"WEB-INF"+File.separator+"lib"); File projectClassbDir = new File(GlobalProperties.PROJECT_PATH+"WEB-INF"+File.separator+"classes"); List<URL> urls = new ArrayList<URL>(); File[] projectLibs = projectLibDir.listFiles(); for(int i=0;projectLibs!=null&&i<projectLibs.length;i++){ urls.add(projectLibs[i].toURL()); } File[] libs = libDir.listFiles(); for(int i=0;libs!=null&&i<libs.length;i++){ urls.add(libs[i].toURL()); } urls.add(classDir.toURL()); urls.add(projectClassbDir.toURL()); classLoader = new URLClassLoader(urls.toArray(new URL[]{})); } catch (Exception e) { e.printStackTrace(); } // } return classLoader; } public static boolean compile(String code,String name){ try { JavaCompiler javaCompiler = ToolProvider.getSystemJavaCompiler(); JavaFileObject fileObject = new StringJavaObject(name, code); List<String> options = new ArrayList<String>(); options.add("-d"); options.add(GlobalProperties.DYNAMIC_CLASS_PATH+File.separator+"classes"+File.separator); options.add("-classpath"); File libDir = new File(GlobalProperties.DYNAMIC_CLASS_PATH+"lib"); File classDir = new File(GlobalProperties.DYNAMIC_CLASS_PATH+File.separator+"classes"+File.separator); File projectLibDir = new File(GlobalProperties.PROJECT_PATH+"WEB-INF"+File.separator+"lib"); File projectClassbDir = new File(GlobalProperties.PROJECT_PATH+"WEB-INF"+File.separator+"classes"+File.separator); StringBuffer path = new StringBuffer(); // File[] projectLibs = projectLibDir.listFiles(); for(int i=0;projectLibs!=null&&i<projectLibs.length;i++){ if(!path.toString().isEmpty()){ path.append(";"); } path.append(projectLibs[i].getCanonicalPath()); } File[] libs = libDir.listFiles(); for(int i=0;libs!=null&&i<libs.length;i++){ if(!path.toString().isEmpty()){ path.append(";"); } path.append(libs[i].getCanonicalPath()); } // path.append(";"); path.append(projectClassbDir.getAbsolutePath()); path.append(";"); path.append(classDir.getAbsolutePath()); options.add(path.toString()); //options.add("-classpath"); //options.add(classDir.getAbsolutePath()); System.out.println(options); CompilationTask task = javaCompiler.getTask(null, null, null, options, null, Arrays.asList(fileObject)); boolean success = task.call(); return success; } catch (Exception e) { e.printStackTrace(); } return false; } public static Class<?> loadClass(String fullName){ try { return getUrlClassLoader().loadClass(fullName); } catch (ClassNotFoundException e) { e.printStackTrace(); } return null; } }