content: /*
   *  Copyright Beijing 58 Information Technology Co.,Ltd.
   *
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you under the Apache License, Version 2.0 (the
   *  "License"); you may not use this file except in compliance
   *  with the License.  You may obtain a copy of the License at
   *
   *        http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing,
   *  software distributed under the License is distributed on an
   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   *  KIND, either express or implied.  See the License for the
   *  specific language governing permissions and limitations
   *  under the License.
   */
  package com.bj58.spat.gaea.server.util;
  
  import java.io.IOException;
  import java.lang.reflect.Method;
  import java.util.Enumeration;
  import java.util.LinkedHashSet;
  import java.util.Set;
  import java.util.jar.JarEntry;
  import java.util.jar.JarFile;
  
  import javassist.ClassPool;
  import javassist.CtClass;
  import javassist.CtMethod;
  import javassist.Modifier;
  import javassist.bytecode.CodeAttribute;
  import javassist.bytecode.LocalVariableAttribute;
  import javassist.bytecode.MethodInfo;
  
  import com.bj58.spat.gaea.server.deploy.hotdeploy.DynamicClassLoader;
  
  /**
   * 
   * @author Service Platform Architecture Team (spat@58.com)
   */
  public class ClassHelper {
  
  	/**
  	 * get all class from jar
  	 * @param jarPath
  	 * @param classLoader
  	 * @return
  	 * @throws IOException
  	 * @throws ClassNotFoundException
  	 */
      public static Set<Class<?>> getClassFromJar(String jarPath, 
      											DynamicClassLoader classLoader) throws IOException, ClassNotFoundException {
          JarFile jarFile = new JarFile(jarPath);
          Enumeration<JarEntry> entries = jarFile.entries();
          Set<Class<?>> classes = new LinkedHashSet<Class<?>>();
          while (entries.hasMoreElements()) {
              JarEntry jarEntry = entries.nextElement();
              String name = jarEntry.getName();
              if (name.endsWith(".class")) {
                  String className = name.replaceAll(".class", "").replaceAll("/", ".");
                  Class<?> cls = null;
                  try {
  //    				cls = classLoader.findClass(className);
                  	cls = classLoader.loadClass(className);
                  } catch (Throwable ex) {
                  	
                  }
                  if (cls != null) {
                      classes.add(cls);
                  }
              }
          }
          return classes;
      }
  
      /**
       * check class is implements the interface
       * @param type
       * @param interfaceType
       * @return
       */
      public static boolean interfaceOf(Class<?> type, Class<?> interfaceType) {
          if (type == null) {
              return false;
          }
          Class<?>[] interfaces = type.getInterfaces();
          for (Class<?> c : interfaces) {
              if (c.equals(interfaceType)) {
                  return true;
              }
          }
          return false;
      }
      
      /**
       * get method parameter names
       * @param cls
       * @param method
       * @return
       * @throws Exception
       */
      public static String[] getParamNames(Class<?> cls, Method method) throws Exception {
      	ClassPool pool = ClassPool.getDefault();  
      	CtClass cc = pool.get(cls.getName());
  
      	Class<?>[] paramAry = method.getParameterTypes();
      	String[] paramTypeNames = new String[paramAry.length];
      	for(int i=0; i<paramAry.length; i++) {
      		paramTypeNames[i] = paramAry[i].getName();
      	}
      	
      	CtMethod cm = cc.getDeclaredMethod(method.getName(), pool.get(paramTypeNames));
  
      	MethodInfo methodInfo = cm.getMethodInfo();  
      	CodeAttribute codeAttribute = methodInfo.getCodeAttribute();  
      	LocalVariableAttribute attr = (LocalVariableAttribute) codeAttribute.getAttribute(LocalVariableAttribute.tag);  
      	if (attr == null)  {
      	    throw new Exception("class:"+cls.getName()+", have no LocalVariableTable, please use javac -g:{vars} to compile the source file");
      	}
      	String[] paramNames = new String[cm.getParameterTypes().length];  
      	int pos = Modifier.isStatic(cm.getModifiers()) ? 0 : 1;  
      	for (int i = 0; i < paramNames.length; i++) {
      	    paramNames[i] = attr.variableName(i + pos);
      	}
      	return paramNames;
      }
      
      
      /**
       * get method parameters annotations
       * @param cls
       * @param method
       * @return
       * @throws Exception
       */
      public static Object[][] getParamAnnotations(Class<?> cls, Method method) throws Exception {
      	ClassPool pool = ClassPool.getDefault();  
      	CtClass cc = pool.get(cls.getName());
  
      	Class<?>[] paramAry = method.getParameterTypes();
      	String[] paramTypeNames = new String[paramAry.length];
      	for(int i=0; i<paramAry.length; i++) {
      		paramTypeNames[i] = paramAry[i].getName();
      	}
      	
      	CtMethod cm = cc.getDeclaredMethod(method.getName(), pool.get(paramTypeNames));
      	return cm.getParameterAnnotations();
      }
      
  }