net.lulihu.ObjectKit.ResourcesLoadKit Maven / Gradle / Ivy

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package net.lulihu.ObjectKit;

import lombok.extern.slf4j.Slf4j;
import sun.net.www.protocol.file.FileURLConnection;

import java.io.*;
import java.net.JarURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.Enumeration;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;

/**
 * jar 资源加载工具
 */
@Slf4j
public class ResourcesLoadKit {

    private static final Class clazz = ResourcesLoadKit.class;

    /**
     * 从jar包下加载文件夹资源
     *
     * @param folderPath       文件夹
     * @param targetFolderPath 目标文件夹
     * @throws IOException 文件拷贝错误时抛出异常
     */
    public static void loadResourcesFromJarByFolder(String folderPath, String targetFolderPath) throws IOException {
        URL url = clazz.getResource(folderPath);
        URLConnection urlConnection = url.openConnection();
        if (urlConnection instanceof FileURLConnection) {
            copyFileResources(url, folderPath, targetFolderPath);
        } else if (urlConnection instanceof JarURLConnection) {
            copyJarResources((JarURLConnection) urlConnection, targetFolderPath);
        }
    }

    /**
     * 当前运行环境资源文件是在文件里面的
     */
    private static void copyFileResources(URL url, String folderPath, String targetFolderPath) throws IOException {
        File root = new File(url.getPath());
        if (root.isDirectory()) {
            File[] files = root.listFiles();
            if (CollectionKit.isEmpty(files)) return;

            for (File file : files) {
                if (file.isDirectory()) {
                    loadResourcesFromJarByFolder(folderPath + "/" + file.getName(), targetFolderPath);
                } else {
                    loadResourcesFromJar(folderPath + "/" + file.getName(), targetFolderPath);
                }
            }
        }
    }

    /**
     * 当前运行环境资源文件是在jar里面的
     */
    private static void copyJarResources(JarURLConnection jarURLConnection, String targetFolderPath) throws IOException {
        try (JarFile jarFile = jarURLConnection.getJarFile()) {
            Enumeration entrys = jarFile.entries();
            while (entrys.hasMoreElements()) {
                JarEntry entry = entrys.nextElement();
                if (entry.getName().startsWith(jarURLConnection.getEntryName()) && !entry.getName().endsWith("/")) {
                    loadResourcesFromJar("/" + entry.getName(), targetFolderPath);
                }
            }
        }
    }

    /**
     * 在jar中加载文件资源
     *
     * @param path             资源文件下的相对文件路径
     * @param targetFolderPath 目标文件夹
     * @throws IOException 文件拷贝错误时抛出异常
     */
    private static void loadResourcesFromJar(String path, String targetFolderPath) throws IOException {
        if (!path.startsWith("/")) {
            throw new IllegalArgumentException("路径必须是绝对的（以'/'开头）。");
        }

        if (path.endsWith("/")) {
            throw new IllegalArgumentException("路径必须是绝对的（不以'/'结尾）。");
        }

        int index = path.lastIndexOf('/');

        String filename = path.substring(index + 1);
        String folderPath = targetFolderPath + path.substring(0, index + 1);

        // 如果该文件夹尚不存在，则将创建该文件夹。如果该文件夹已存在，则将被忽略
        File dir = new File(folderPath);
        if (!dir.exists()) dir.mkdirs();

        // 如果该文件尚不存在，则将创建该文件。如果文件已存在，则将被忽略
        filename = folderPath + filename;
        File file = new File(filename);

        if (!file.exists() && !file.createNewFile()) {
            log.error("创建文件失败,文件名:{}", filename);
            return;
        }

        // 准备缓冲区以进行数据复制
        byte[] buffer = new byte[1024];
        int readBytes;

        try (InputStream is = loadResourcesInputStream(path)) {
            if (is == null) throw new FileNotFoundException("文件 " + path + " 在JAR里面找不到");

            try (OutputStream os = new FileOutputStream(file)) {
                while ((readBytes = is.read(buffer)) != -1) {
                    os.write(buffer, 0, readBytes);
                }
            }
        }
    }

    /**
     * 加载资源输入流
     *
     * @param path 资源地址
     * @return {@linkplain InputStream}
     * @throws IOException 文件异常
     */
    public static InputStream loadResourcesInputStream(String path) throws IOException {
        URL url = clazz.getResource(path);
        URLConnection urlConnection = url.openConnection();
        return urlConnection.getInputStream();
    }
}