J2EE常用工具类—文件打包解包处理类

package cn.org.jshuwei.j2ee.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Enumeration;

import org.apache.tools.zip.ZipEntry;
import org.apache.tools.zip.ZipFile;
import org.apache.tools.zip.ZipOutputStream;

/**
* 文件压缩解压工具类
* 
* @author huwei(jshuwei.org.cn)
* @since 1.2
* 
*/
public class ZipUtil {
    /**
     * 压缩ZIP文件，将baseDirName目录下的所有文件压缩到targetFileName.ZIP文件中
     * 
     * @param baseDirName
     *            需要压缩的文件的跟目录
     * @param targetFileName
     *            压缩有生成的文件名
     */
    public static void zipFile(String baseDirName, String targetFileName) {
        if (baseDirName == null) {
            return;
        }
        File file = new File(baseDirName);
        if (!file.exists()) {
            return;
        }
        String baseDirPath = file.getAbsolutePath();
        File targetFile = new File(targetFileName);
        try {
            ZipOutputStream out = new ZipOutputStream(new FileOutputStream(
                    targetFile));
            if (file.isFile()) {
                fileToZip(baseDirPath, file, out);
            } else {
                dirToZip(baseDirPath, file, out);
            }
            out.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 解压缩ZIP文件，将ZIP文件里的内容解压到targetBaseDirName目录下
     * 
     * @param zipFileName
     *            待解压缩的ZIP文件名
     * @param targetBaseDirName
     *            目标目录
     */
    @SuppressWarnings("unchecked")
    public static void unzipFile(String zipFileName, String targetBaseDirName) {
        if (!targetBaseDirName.endsWith(File.separator)) {
            targetBaseDirName += File.separator;
        }
        try {
            ZipFile zipFile = new ZipFile(zipFileName);
            ZipEntry entry = null;
            String entryName = null;
            String targetFileName = null;
            byte[] buffer = new byte[4096];
            int bytes_read;
            Enumeration entrys = zipFile.getEntries();//.entries();
            while (entrys.hasMoreElements()) {
                entry = (ZipEntry) entrys.nextElement();
                entryName = entry.getName();
                targetFileName = targetBaseDirName + entryName;
                if (entry.isDirectory()) {
                    new File(targetFileName).mkdirs();
                    continue;
                } else {
                    new File(targetFileName).getParentFile().mkdirs();
                }
                File targetFile = new File(targetFileName);
                FileOutputStream os = new FileOutputStream(targetFile);
                InputStream is = zipFile.getInputStream(entry);
                while ((bytes_read = is.read(buffer)) != -1) {
                    os.write(buffer, 0, bytes_read);
                }
                os.close();
                is.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static void dirToZip(String baseDirPath, File dir,
            ZipOutputStream out) {
        if (dir.isDirectory()) {
            File[] files = dir.listFiles();
            if (files.length == 0) {
                ZipEntry entry = new ZipEntry(getEntryName(baseDirPath, dir));
                try {
                    out.putNextEntry(entry);
                    out.closeEntry();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                return;
            }
            for (int i = 0; i < files.length; i++) {
                if (files[i].isFile()) {
                    fileToZip(baseDirPath, files[i], out);
                } else {
                    dirToZip(baseDirPath, files[i], out);
                }
            }
        }
    }

    private static void fileToZip(String baseDirPath, File file,
            ZipOutputStream out) {
        FileInputStream in = null;
        ZipEntry entry = null;
        byte[] buffer = new byte[4096];
        int bytes_read;
        if (file.isFile()) {
            try {
                in = new FileInputStream(file);
                entry = new ZipEntry(getEntryName(baseDirPath, file));
                out.putNextEntry(entry);
                while ((bytes_read = in.read(buffer)) != -1) {
                    out.write(buffer, 0, bytes_read);
                }
                out.closeEntry();
                in.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    private static String getEntryName(String baseDirPath, File file) {
        if (!baseDirPath.endsWith(File.separator)) {
            baseDirPath += File.separator;
        }
        String filePath = file.getAbsolutePath();
        if (file.isDirectory()) {
            filePath += "/";
        }
        int index = filePath.indexOf(baseDirPath);
        return filePath.substring(index + baseDirPath.length());
    }
}