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Java文件压缩工具类：ZipUtil.java

问题记录时间：2023.10.09

整理博客时间：2024.01.13

import java.io.*;
import java.net.URL;
import java.util.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class ZipUtil {

    public static ByteArrayOutputStream downloadAndZip(List<Map<String, String>> fileInfoList) throws IOException {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        ZipOutputStream zos = new ZipOutputStream(byteArrayOutputStream);

        for (final Map<String, String> fileInfo : fileInfoList) {
            String url = fileInfo.get("url");
            String fileName = fileInfo.get("fileName");

            URL downloadUrl = new URL(url);
            ZipEntry zipEntry = new ZipEntry(fileName);
            zos.putNextEntry(zipEntry);

            try (InputStream is = downloadUrl.openStream()) {
                byte[] buffer = new byte[1024];
                int len;
                while ((len = is.read(buffer)) != -1) {
                    zos.write(buffer, 0, len);
                }
            }

            zos.closeEntry();
        }

        zos.close();
        return byteArrayOutputStream;
    }

    public static void saveToFile(ByteArrayOutputStream byteArrayOutputStream, String filePath) throws IOException {
        File file = new File(filePath);
        try (FileOutputStream fos = new FileOutputStream(file)) {
            byteArrayOutputStream.writeTo(fos);
        }
    }

    public static void main(String[] args) throws Exception {
        LinkedList<Map<String, String>> s = new LinkedList<>();

        HashMap<String, String> file1 = new HashMap<>();
        file1.put("url", "https://img1.baidu.com/it/u=3007048469,3759326707&fm=253&app=138&size=w931&n=0&f=JPEG&fmt=auto?sec=1");
        file1.put("fileName", "图片1.png");
        s.add(file1);
        HashMap<String, String> file2 = new HashMap<>();
        file2.put("url", "http://csi.hubu.edu.cn/fujian1-zhongguojisuanjixuehuituijianguojixueshuhuiyiheqikanmulu-2022nian.pdf");
        file2.put("fileName", "folder/pdf2.pdf");
        s.add(file2);

        ByteArrayOutputStream outputStream = downloadAndZip(s);
        saveToFile(outputStream, "D:/test.zip");
    }
}

添加文件名重复校验（重复文件名在后面加 (n)）

import java.io.*;
import java.net.URL;
import java.util.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class ZipUtil {

    private static String duplicateFilenameDetect(HashMap<String, Integer> map, String filename) {
        Integer count = map.getOrDefault(filename, 0);
        map.put(filename, count + 1);
        if (count > 0) {
            String suffix = "(" + (count + 1) + ")";
            int lastDotIndex = filename.lastIndexOf('.');
            if (lastDotIndex > 0) {
                String prefix = filename.substring(0, lastDotIndex);
                String postfix = filename.substring(lastDotIndex);

                return prefix + suffix + postfix;
            } else {
                return filename + suffix;
            }
        } else {
            return filename;
        }
    }

    public static ByteArrayOutputStream downloadAndZip(List<Map<String, String>> fileInfoList) throws IOException {
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        ZipOutputStream zos = new ZipOutputStream(byteArrayOutputStream);

        HashMap<String, Integer> duplicateFilenameDetectionMap = new HashMap<>();

        for (final Map<String, String> fileInfo : fileInfoList) {
            String url = fileInfo.get("url");
            String rawFileName = fileInfo.get("fileName");
            String fileName = duplicateFilenameDetect(duplicateFilenameDetectionMap, rawFileName);

            URL downloadUrl = new URL(url);
            ZipEntry zipEntry = new ZipEntry(fileName);
            zos.putNextEntry(zipEntry);

            try (InputStream is = downloadUrl.openStream()) {
                byte[] buffer = new byte[1024];
                int len;
                while ((len = is.read(buffer)) != -1) {
                    zos.write(buffer, 0, len);
                }
            }

            zos.closeEntry();
        }

        zos.close();
        return byteArrayOutputStream;
    }

    public static void saveToFile(ByteArrayOutputStream byteArrayOutputStream, String filePath) throws IOException {
        File file = new File(filePath);
        try (FileOutputStream fos = new FileOutputStream(file)) {
            byteArrayOutputStream.writeTo(fos);
        }
    }

    public static void main(String[] args) throws Exception {
        LinkedList<Map<String, String>> s = new LinkedList<>();

        HashMap<String, String> file1 = new HashMap<>();
        file1.put("url", "https://img1.baidu.com/it/u=3007048469,3759326707&fm=253&app=138&size=w931&n=0&f=JPEG&fmt=auto?sec=1");
        file1.put("fileName", "图片1.png");
        s.add(file1);
        HashMap<String, String> file2 = new HashMap<>();
        file2.put("url", "http://csi.hubu.edu.cn/fujian1-zhongguojisuanjixuehuituijianguojixueshuhuiyiheqikanmulu-2022nian.pdf");
        file2.put("fileName", "folder/pdf2.pdf");
        s.add(file2);
        // 验证重名加 (n) 逻辑
        HashMap<String, String> file3 = new HashMap<>();
        file3.put("url", "https://img0.baidu.com/it/u=3182669744,3015526205&fm=253&app=138&size=w931&n=0&f=JPEG&fmt=auto?sec=1");
        file3.put("fileName", "图片1.png");
        s.add(file3);

        ByteArrayOutputStream outputStream = downloadAndZip(s);
        saveToFile(outputStream, "D:/test.zip");
    }
}

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