org.fastquery.util.ClassUtil Maven / Gradle / Ivy
/*
* Copyright (c) 2016-2017, fastquery.org and/or its affiliates. All rights reserved.
*
* 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.
*
* For more information, please see http://www.fastquery.org/.
*
*/
package org.fastquery.util;
import java.io.File;
import java.io.IOException;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import org.fastquery.core.Repository;
import org.fastquery.core.RepositoryException;
/**
*
* @author ohergal
* @author xixifeng ([email protected])
*/
public class ClassUtil {
private ClassUtil(){}
/**
* 从包package中获取所有的Class
* @param packageName 包地址
* @return clazz 集
*/
@SuppressWarnings("unchecked")
public static List> getClasses(String packageName){
//第一个class类的集合
List> classes = new ArrayList<>();
// packageName 很可能是一个完整的类
try {
Class clazz = (Class) Class.forName(packageName);
if(Repository.class.isAssignableFrom(clazz)){
classes.add(clazz);
}
} catch (ClassNotFoundException e1) {}
//是否循环迭代
boolean recursive = true;
//获取包的名字 并进行替换
String packageDirName = packageName.replace('.', '/');
//定义一个枚举的集合 并进行循环来处理这个目录下的things
Enumeration dirs;
try {
dirs = Thread.currentThread().getContextClassLoader().getResources(packageDirName);
//循环迭代下去
while (dirs.hasMoreElements()){
//获取下一个元素
URL url = dirs.nextElement();
//得到协议的名称
String protocol = url.getProtocol();
//如果是以文件的形式保存在服务器上
if ("file".equals(protocol)) {
//获取包的物理路径
String filePath = URLDecoder.decode(url.getFile(), "UTF-8");
//以文件的方式扫描整个包下的文件 并添加到集合中
findAndAddClassesInPackageByFile(packageName, filePath, recursive, classes);
} else if ("jar".equals(protocol)){
//如果是jar包文件
//定义一个JarFile
JarFile jar;
try {
//获取jar
jar = ((JarURLConnection) url.openConnection()).getJarFile();
//从此jar包 得到一个枚举类
Enumeration entries = jar.entries();
//同样的进行循环迭代
while (entries.hasMoreElements()) {
//获取jar里的一个实体 可以是目录 和一些jar包里的其他文件 如META-INF等文件
JarEntry entry = entries.nextElement();
String name = entry.getName();
//如果是以/开头的
if (name.charAt(0) == '/') {
//获取后面的字符串
name = name.substring(1);
}
//如果前半部分和定义的包名相同
if (name.startsWith(packageDirName)) {
int idx = name.lastIndexOf('/');
//如果以"/"结尾 是一个包
if (idx != -1) {
//获取包名 把"/"替换成"."
packageName = name.substring(0, idx).replace('/', '.');
}
//如果可以迭代下去 并且是一个包
if ((idx != -1) || recursive){
//如果是一个.class文件 而且不是目录
if (name.endsWith(".class") && !entry.isDirectory()) {
//去掉后面的".class" 获取真正的类名
String className = name.substring(packageName.length() + 1, name.length() - 6);
try {
Class clsr = (Class) Class.forName(packageName + '.' + className);
if(Repository.class.isAssignableFrom(clsr)){
//添加到classes
classes.add(clsr);
}
} catch (ClassNotFoundException e) {
throw new RepositoryException(e);
}
}
}
}
}
} catch (IOException e) {
throw new RepositoryException(e);
}
}
}
} catch (IOException e) {
throw new RepositoryException(e);
}
return classes;
}
/**
* 以文件的形式来获取包下的所有Class
* @param packageName
* @param packagePath
* @param recursive
* @param classes
*/
@SuppressWarnings("unchecked")
private static void findAndAddClassesInPackageByFile(String packageName, String packagePath, final boolean recursive, List> classes){
//获取此包的目录 建立一个File
File dir = new File(packagePath);
//如果不存在或者 也不是目录就直接返回
if (!dir.exists() || !dir.isDirectory()) {
return;
}
//如果存在 就获取包下的所有文件 包括目录
File[] dirfiles = dir.listFiles( file ->
//自定义过滤规则 如果可以循环(包含子目录) 或则是以.class结尾的文件(编译好的java类文件)
(recursive && file.isDirectory()) || (file.getName().endsWith(".class"))
);
//循环所有文件
for (File file : dirfiles) {
//如果是目录 则继续扫描
if (file.isDirectory()) {
findAndAddClassesInPackageByFile(packageName + "." + file.getName(),
file.getAbsolutePath(),
recursive,
classes);
}
else {
//如果是java类文件 去掉后面的.class 只留下类名
String className = file.getName().substring(0, file.getName().length() - 6);
try {
Class rcls = (Class) Class.forName(packageName + '.' + className);
if(Repository.class.isAssignableFrom(rcls)){
//添加到集合中去
classes.add(rcls);
}
} catch (ClassNotFoundException e) {
throw new RepositoryException(e);
}
}
}
}
}
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