java实现简单的压缩和解压缩文件（包含多级文件夹和空文件夹）

最近在学习java的io知识，写了一个简单地压缩和解压缩的程序，只能实现对文字型（像txt，world）文件的压缩，无法对图片等压缩，在这个过程中遇到的最大困难是空目录的处理，下面看代码

实现压缩文件

package io;

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.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

public class ZipOutputStreamDemo {
	private File file;
	private File zipFile;
	private InputStream input;
	private ZipOutputStream zipOut;
	
	//构造函数
	public ZipOutputStreamDemo(File file) throws FileNotFoundException {
		this.file = file;
		this.zipFile = new File (file.getAbsolutePath()+".zip");
		InputStream input = null;
		this.zipOut = new ZipOutputStream(new FileOutputStream(zipFile));	
	}

	//实现对文件（夹）的压缩
	public  void compressFile (File directory) throws IOException {
		if (directory != null) {
			if (directory.isDirectory()) {
				File [] f = directory.listFiles();
				if (f!=null) {
					//目录里面文件数为0，即空目录，此时在压缩包中相对路径下创建一个空目录
					if (f.length==0) {
						this.zipOut.putNextEntry(new ZipEntry (this.getPath(directory)+File.separator));
					}
					//递归调用compressFile函数，找出所有的文件
					else {
						for (int i=0;i<f.length;i++) {
							compressFile (f[i]);
						}
					}
				}
			}
			//对找出的文件进行压缩处理
			else {
				System.out.println(directory);
				this.input = new FileInputStream (directory);
				this.zipOut.putNextEntry(new ZipEntry (this.getPath(directory)));
				int temp = 0;
				while ((temp=input.read())!=-1) {
					this.zipOut.write(temp);
				}
				this.input.close();
				
			}
		}
	}
	
	//获得该文件在压缩包中的相对路径
	public String getPath (File f) {
		String str1 = this.file.getAbsolutePath();
		int n1= str1.length();
		String str2 = f.getAbsolutePath();
		int n2= str2.length();
		String str3 = this.file.getName();
		int n3= str3.length();
		String str = str2.substring(n1-n3, n2);
		return str;	
	}
}

实现文件的解压缩

package io;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipException;
import java.util.zip.ZipFile;
import java.util.zip.ZipInputStream;

public class ZipInputStreamDemo {
	private File file;
	private File outFile;
	private ZipInputStream zipInput;
	private ZipFile zipFile;	
	private ZipEntry entry;
	private InputStream input;
	private OutputStream out;
	//构造函数
	public ZipInputStreamDemo(File file) throws ZipException, IOException {
		this.file = file;
		this.outFile = null;
		this.zipFile = new ZipFile (file);
		this.zipInput = new ZipInputStream(new FileInputStream(this.file));
		this.entry = null;
		this.input=null;
		this.out=null;
	}
	//对压缩包中的文件进行解压缩
	public void decompress () throws IOException {
		//用getNextEntry获得压缩包中的下一个文件条目并解压缩，直到没有文件了结束循环
		while ((this.entry=this.zipInput.getNextEntry())!=null) {
			System.out.println("解压缩"+this.entry.getName()+"文件");
			this.outFile = new File ("e:"+File.separator+this.entry.getName());
			//如果父路径的文件夹不存在，就创建该文件夹
			if (!this.outFile.getParentFile().exists()) {
				this.outFile.getParentFile().mkdirs();
			}
			if (!outFile.exists()) {
				//当该文件条目为一个空目录时，创建该空目录
				if (this.entry.getName().substring(this.entry.getName().length()-1,this.entry.getName().length()).equals(File.separator)) {
					outFile.mkdirs();
				}
				//在解压的路径下创建该文件条目对应的文件
				else {
					this.outFile.createNewFile();
				}
			}
			if (!outFile.isDirectory()) {
				this.input = this.zipFile.getInputStream(entry);
				this.out=new FileOutputStream (this.outFile);
				int temp = 0;
				while ((temp=input.read())!=-1) {
					out.write(temp);
				}
				this.input.close();
				this.out.close();
			}
		}
	}
}

代码亲测在eclipse下运行有效