Apache Commons是Apache軟體基金會的專案，曾隸屬於Jakarta專案。Commons的目的是提供可重用的、開源的Java程式碼。Apache Commons包含了很多開源的工具，用於解決平時程式設計經常會遇到的問題，減少重複勞動。

Compress

       本例主要介紹元件Compress，Compress是ApacheCommons提供壓縮、解壓縮檔案的類庫，可以操作ar, cpio, Unix dump, tar, zip,gzip, XZ, Pack200 and bzip2格式的檔案，功能比較強大。本例主要演示Compress操作對zip檔案壓縮與解壓縮的操作。

1、檔案壓縮成zip格式壓縮包

         /**
	 * 將檔案打包成zip壓縮包檔案
	 */
	private static void compressFiles2Zip(){
		long startInt = System.currentTimeMillis();
		File file1 = new File("D:\\logs\\log4j.log");
		File file2 = new File("D:\\logs\\log4j.log.2016-07-31-19");
		
		List<File> files = new ArrayList<File>();
		files.add(file1);
		files.add(file2);
		File zipFile = new File("D:\\logs\\log4j.log.zip");
		InputStream inputStream = null;
		ZipArchiveOutputStream zipArchiveOutputStream = null;
		try {
			zipArchiveOutputStream = new ZipArchiveOutputStream(zipFile);
			zipArchiveOutputStream.setUseZip64(Zip64Mode.AsNeeded);
			for(File file : files){
				//將每個檔案用ZipArchiveEntry封裝，使用ZipArchiveOutputStream寫到壓縮檔案
				ZipArchiveEntry zipArchiveEntry = new ZipArchiveEntry(file, "test"+File.separator+file.getName());
				zipArchiveOutputStream.putArchiveEntry(zipArchiveEntry);
				
				inputStream = new FileInputStream(file);
				byte[] buffer = new byte[1024 * 5]; 
				int len = -1;
				while((len = inputStream.read(buffer)) != -1) {
					//把緩衝區的位元組寫入到ZipArchiveEntry
					zipArchiveOutputStream.write(buffer, 0, len);
				}
			}
			zipArchiveOutputStream.closeArchiveEntry();
			zipArchiveOutputStream.finish();
		} catch (IOException e) {
//			e.printStackTrace();
		}finally{
			//關閉輸入流
			if(null!=inputStream){
				try {
					inputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
			//關閉輸出流
			if(null!=zipArchiveOutputStream){
				try {
					zipArchiveOutputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
		}
		System.out.println("耗時："+(System.currentTimeMillis()-startInt)+"毫秒");
	}
 

2、zip壓縮包解壓成檔案到指定資料夾

        /**
	 * 將zip壓縮包解壓成檔案到指定資料夾
	 */
	private static void decompressZip2Files(){
		long startInt = System.currentTimeMillis();
		String zipFilePath = "D:\\logs\\log4j.log.zip";
		File zipFile = new File(zipFilePath);
		InputStream inputStream = null;
		OutputStream outputStream = null;
		//zip檔案輸入流
		ZipArchiveInputStream zipArchiveInputStream = null;
		ArchiveEntry archiveEntry = null;
		try {
			inputStream = new FileInputStream(new File(zipFilePath));
			zipArchiveInputStream = new ZipArchiveInputStream(inputStream,"UTF-8");
			while(null!=(archiveEntry = zipArchiveInputStream.getNextEntry())){
				//獲取檔名
				String archiveEntryFileName = archiveEntry.getName();
				//構造解壓後文件的存放路徑
				String archiveEntryPath = "D:\\logs\\test\\" + archiveEntryFileName;
				byte[] content = new byte[(int) archiveEntry.getSize()];
				zipArchiveInputStream.read(content);
				//把解壓出來的檔案寫到指定路徑
				File entryFile  = new File(archiveEntryPath);
				if(!entryFile.exists()){
					entryFile.getParentFile().mkdirs();
				}
				outputStream = new FileOutputStream(entryFile);
				outputStream.write(content);
				outputStream.flush();
			}
		} catch (FileNotFoundException e) {
//			e.printStackTrace();
		} catch (IOException e) {
//			e.printStackTrace();
		}finally{
			if(null!=outputStream){
				try {
					outputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
			if(null!=zipArchiveInputStream){
				try {
					zipArchiveInputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
			if(null!=inputStream){
				try {
					inputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
		}
		System.out.println("耗時："+(System.currentTimeMillis()-startInt)+"毫秒");
	}
 

       以上分別演示zip檔案壓縮和解壓縮的過程，以下將zip檔案壓縮和解壓縮抽取成公共方法，但是其中未新增檔案格式校驗等操作，需要讀者自行補充。

package com.mahaochen.apache.commons.Compress;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.apache.commons.compress.archivers.ArchiveEntry;
import org.apache.commons.compress.archivers.zip.Zip64Mode;
import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
import org.apache.commons.compress.archivers.zip.ZipArchiveInputStream;
import org.apache.commons.compress.archivers.zip.ZipArchiveOutputStream;

public class CommCompressZipFileUtil {

	/**
	 * 將檔案打包成zip壓縮包檔案
	 * @param files
	 * @param targetFilePath
	 * @return
	 */
	public boolean compressFiles2Zip(File[] files,String targetFilePath){
		
		InputStream inputStream = null;
		ZipArchiveOutputStream zipArchiveOutputStream = null;
		try {
			File zipFile = new File(targetFilePath);
			zipArchiveOutputStream = new ZipArchiveOutputStream(zipFile);
			//Use Zip64 extensions for all entries where they are required
			zipArchiveOutputStream.setUseZip64(Zip64Mode.AsNeeded);
			for(File file : files){
				//將每個檔案用ZipArchiveEntry封裝，使用ZipArchiveOutputStream寫到壓縮檔案
				ZipArchiveEntry zipArchiveEntry = new ZipArchiveEntry(file, file.getName());
				zipArchiveOutputStream.putArchiveEntry(zipArchiveEntry);
				
				inputStream = new FileInputStream(file);
				byte[] buffer = new byte[1024 * 5]; 
				int len = -1;
				while((len = inputStream.read(buffer)) != -1) {
					//把緩衝區的位元組寫入到ZipArchiveEntry
					zipArchiveOutputStream.write(buffer, 0, len);
				}
			}
			zipArchiveOutputStream.closeArchiveEntry();
			zipArchiveOutputStream.finish();
		} catch (IOException e) {
//			e.printStackTrace();
			return false;
		}finally{
			//關閉輸入流
			if(null!=inputStream){
				try {
					inputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
			//關閉輸出流
			if(null!=zipArchiveOutputStream){
				try {
					zipArchiveOutputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
		}
		return true;
	}
	
	/**
	 * 將zip壓縮包解壓成檔案到指定資料夾
	 * @param zipFilePath
	 * @param targetDirPath
	 * @return
	 */
	public boolean decompressZip2Files(String zipFilePath,String targetDirPath){
		
		InputStream inputStream = null;
		OutputStream outputStream = null;
		//zip檔案輸入流
		ZipArchiveInputStream zipArchiveInputStream = null;
		ArchiveEntry archiveEntry = null;
		try {
			File zipFile = new File(zipFilePath);
			inputStream = new FileInputStream(zipFile);
			zipArchiveInputStream = new ZipArchiveInputStream(inputStream,"UTF-8");
			
			while(null!=(archiveEntry = zipArchiveInputStream.getNextEntry())){
				//獲取檔名
				String archiveEntryFileName = archiveEntry.getName();
				//構造解壓後文件的存放路徑
				String archiveEntryPath = targetDirPath + archiveEntryFileName;
				//把解壓出來的檔案寫到指定路徑
				File entryFile  = new File(archiveEntryPath);
				if(!entryFile.exists()){
					entryFile.getParentFile().mkdirs();
				}
				byte[] buffer = new byte[1024 * 5];
				outputStream = new FileOutputStream(entryFile);
				int len = -1;
				while((len = zipArchiveInputStream.read(buffer)) != -1){
					outputStream.write(buffer,0,len);
				}
				outputStream.flush();
			}
		} catch (FileNotFoundException e) {
//			e.printStackTrace();
			return false;
		} catch (IOException e) {
//			e.printStackTrace();
			return false;
		}finally{
			if(null!=outputStream){
				try {
					outputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
			if(null!=zipArchiveInputStream){
				try {
					zipArchiveInputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
			if(null!=inputStream){
				try {
					inputStream.close();
				} catch (IOException e) {
//					e.printStackTrace();
				}
			}
		}
		return true;
	}
}