AddFileToZip.java

package util;

import java.io.*;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;
import java.util.zip.ZipOutputStream;

/**
 * 直接给zip新增文件
 * 对比：25M zip
 * 先解压，新增文件，再压缩  --> 13s
 * 本方法    --> 5s
 * @version 2017/6/15.
 */
public class AddFileToZip {
    public static void main(String[] args) throws Exception {
        addFilesToExistingZip(new File("D:\\1.zip"), new File[] {new File("D:\\log.txt")});
    }

    public static void addFilesToExistingZip(File zipFile, File[] files) throws IOException {
        // get a temp file
        File tempFile = File.createTempFile(zipFile.getName(), null);
        // delete it, otherwise you cannot rename your existing zip to it.
        tempFile.delete();

        boolean renameOk = zipFile.renameTo(tempFile);
        if (!renameOk) {
            throw new RuntimeException(
                            "could not rename the file " + zipFile.getAbsolutePath() + " to " + tempFile.getAbsolutePath());
        }
        byte[] buf = new byte[1024];

        ZipInputStream zin = new ZipInputStream(new FileInputStream(tempFile));
        ZipOutputStream out = new ZipOutputStream(new FileOutputStream(zipFile));

        ZipEntry entry = zin.getNextEntry();
        while (entry != null) {
            String name = entry.getName();
            boolean notInFiles = true;
            for (File f : files) {
                if (f.getName().equals(name)) {
                    notInFiles = false;
                    break;
                }
            }
            if (notInFiles) {
                // Add ZIP entry to output stream.
                out.putNextEntry(new ZipEntry(name));
                // Transfer bytes from the ZIP file to the output file
                int len;
                while ((len = zin.read(buf)) > 0) {
                    out.write(buf, 0, len);
                }
            }
            entry = zin.getNextEntry();
        }
        // Close the streams
        zin.close();
        // Compress the files
        for (int i = 0; i < files.length; i++) {
            InputStream in = new FileInputStream(files[i]);
            // Add ZIP entry to output stream.
            out.putNextEntry(new ZipEntry(files[i].getName()));
            // Transfer bytes from the file to the ZIP file
            int len;
            while ((len = in.read(buf)) > 0) {
                out.write(buf, 0, len);
            }
            // Complete the entry
            out.closeEntry();
            in.close();
        }
        // Complete the ZIP file
        out.close();
        tempFile.delete();
    }
}