java 查找指定包下的类

package com.jason.test;

import java.io.File;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.net.URL;

import java.net.URLClassLoader;

import java.util.ArrayList;

import java.util.Enumeration;

import java.util.List;

import java.util.jar.JarEntry;

import java.util.jar.JarFile;

/**

 * @author jiangzeyin

 * @date 2016-9-9

 */

public class PackageUtil {

    /**

     * 获取某包下（包括该包的所有子包）所有类

     *

     * @param packageName 包名

     * @return 类的完整名称

     * @throws UnsupportedEncodingException

     */

    public static List<String> getClassName(String packageName) throws IOException {

        return getClassName(packageName, true);

    }

    public static void main(String[] args) throws IOException {

        List<String> list = getClassName("org.apache.spark");

        for (String s : list) {

            System.out.println(s);

        }

    }

    /**

     * 获取某包下所有类

     *

     * @param packageName  包名

     * @param childPackage 是否遍历子包

     * @return 类的完整名称

     * @throws UnsupportedEncodingException

     */

    public static List<String> getClassName(String packageName, boolean childPackage) throws IOException {

        List<String> fileNames = new ArrayList<>();

        ClassLoader loader = Thread.currentThread().getContextClassLoader();

        String packagePath = packageName.replace(".", "/");

        Enumeration<URL> urls = loader.getResources(packagePath);

        while (urls.hasMoreElements()) {

            URL url = urls.nextElement();

            if (url == null)

                continue;

            String type = url.getProtocol();

            if (type.equals("file")) {

                fileNames.addAll(getClassNameByFile(url.getPath(), childPackage));

            } else if (type.equals("jar")) {

                fileNames.addAll(getClassNameByJar(url.getPath(), childPackage));

            }

        }

        fileNames.addAll(getClassNameByJars(((URLClassLoader) loader).getURLs(), packagePath, childPackage));

        return fileNames;

    }

    /**

     * 从项目文件获取某包下所有类

     *

     * @param filePath     文件路径

     *                     类名集合

     * @param childPackage 是否遍历子包

     * @return 类的完整名称

     * @throws UnsupportedEncodingException

     */

    private static List<String> getClassNameByFile(String filePath, boolean childPackage) throws UnsupportedEncodingException {

        List<String> myClassName = new ArrayList<>();

        //filePath = UrlDecode.getURLDecode(filePath);

        File file = new File(filePath);

        File[] childFiles = file.listFiles();

        if (childFiles == null)

            return myClassName;

        for (File childFile : childFiles) {

            if (childFile.isDirectory()) {

                if (childPackage) {

                    myClassName.addAll(getClassNameByFile(childFile.getPath(), childPackage));

                }

            } else {

                String childFilePath = childFile.getPath();

                //childFilePath = FileUtil.clearPath(childFilePath);

                if (childFilePath.endsWith(".class")) {

                    childFilePath = childFilePath.substring(childFilePath.indexOf("/classes/") + 9, childFilePath.lastIndexOf("."));

                    childFilePath = childFilePath.replace("/", ".");

                    myClassName.add(childFilePath);

                }

            }

        }

        return myClassName;

    }

    /**

     * 从jar获取某包下所有类

     *

     * @param jarPath      jar文件路径

     * @param childPackage 是否遍历子包

     * @return 类的完整名称

     * @throws UnsupportedEncodingException

     */

    private static List<String> getClassNameByJar(String jarPath, boolean childPackage) throws UnsupportedEncodingException {

        List<String> myClassName = new ArrayList<String>();

        String[] jarInfo = jarPath.split("!");

        String jarFilePath = jarInfo[0].substring(jarInfo[0].indexOf("/"));

        //jarFilePath = UrlDecode.getURLDecode(jarFilePath);

        String packagePath = jarInfo[1].substring(1);

        try {

            JarFile jarFile = new JarFile(jarFilePath);

            Enumeration<JarEntry> entrys = jarFile.entries();

            while (entrys.hasMoreElements()) {

                JarEntry jarEntry = entrys.nextElement();

                String entryName = jarEntry.getName();

                if (entryName.endsWith(".class")) {

                    if (childPackage) {

                        if (entryName.startsWith(packagePath)) {

                            entryName = entryName.replace("/", ".").substring(0, entryName.lastIndexOf("."));

                            myClassName.add(entryName);

                        }

                    } else {

                        int index = entryName.lastIndexOf("/");

                        String myPackagePath;

                        if (index != -1) {

                            myPackagePath = entryName.substring(0, index);

                        } else {

                            myPackagePath = entryName;

                        }

                        if (myPackagePath.equals(packagePath)) {

                            entryName = entryName.replace("/", ".").substring(0, entryName.lastIndexOf("."));

                            myClassName.add(entryName);

                        }

                    }

                }

            }

        } catch (Exception e) {

            //SystemLog.Log(LogType.systemInfo, e.getMessage(), e);

        }

        return myClassName;

    }

    /**

     * 从所有jar中搜索该包，并获取该包下所有类

     *

     * @param urls         URL集合

     * @param packagePath  包路径

     * @param childPackage 是否遍历子包

     * @return 类的完整名称

     * @throws UnsupportedEncodingException

     */

    private static List<String> getClassNameByJars(URL[] urls, String packagePath, boolean childPackage) throws UnsupportedEncodingException {

        List<String> myClassName = new ArrayList<String>();

        if (urls != null) {

            for (int i = 0; i < urls.length; i++) {

                URL url = urls[i];

                String urlPath = url.getPath();

                // 不必搜索classes文件夹

                if (urlPath.endsWith("classes/")) {

                    continue;

                }

                String jarPath = urlPath + "!/" + packagePath;

                myClassName.addAll(getClassNameByJar(jarPath, childPackage));

            }

        }

        return myClassName;

    }

}