Java 讀寫GZIP格式文件代碼

使用GZIP格式壓縮文本以縮減文件大小，于是乎接觸到了 GZIPInputStream/ GZIPOutputStream這兩個類，還有 ByteArrayOutputStream這個類。這里寫了一個簡單的示例代碼記錄一下

import java.io.ByteArrayOutputStream;

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.GZIPInputStream;

import java.util.zip.GZIPOutputStream;

public class GZipFileTest {

private static final int BUFFER_SIZE = 1024;  
/** 
 * @param args 
 */  
public static void main(String[] args) {  

    File inputFile = new File("D:/test/input.txt");  

    File outputFile = new File("D:/test/test.dat");  

    writeGZip(inputFile,outputFile);  

    readGZip(outputFile);  
}  

public static void readGZip(File file) {  

    GZIPInputStream gzipInputStream = null;  
    ByteArrayOutputStream baos = null;  
    try {  
        gzipInputStream = new GZIPInputStream(new FileInputStream(file));  

        baos = new ByteArrayOutputStream();  

        byte[] buf = new byte[BUFFER_SIZE];  
        int len = 0;  
        while((len=gzipInputStream.read(buf, 0, BUFFER_SIZE))!=-1){  
            baos.write(buf, 0, len);  
        }  

        baos.toByteArray();  

        String result = baos.toString("UTF-8");  

        System.out.println("result="+result);  

    } catch (FileNotFoundException e) {  
        e.printStackTrace();  
    } catch (IOException e) {  
        e.printStackTrace();  
    }finally{  
        if(gzipInputStream!=null){  
            try {  
                gzipInputStream.close();  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
        if(baos!=null){  
            try {  
                baos.close();  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
    }  
}  

public static void writeGZip(File inputFile, File outputFile) {  

    GZIPOutputStream gzipOutputStream = null;  
    InputStream in = null;  
    try {  
        gzipOutputStream = new GZIPOutputStream(new FileOutputStream(outputFile));  

        in = new FileInputStream(inputFile);  

        byte[] buffer = new byte[BUFFER_SIZE];  

        int len = 0;  
        while ((len = in.read(buffer,0,BUFFER_SIZE)) > 0) {  
            gzipOutputStream.write(buffer, 0, len);  
        }  
        gzipOutputStream.finish();  

    } catch (FileNotFoundException e) {  
        e.printStackTrace();  
    } catch (IOException e) {  
        e.printStackTrace();  
    }finally{  
        if(gzipOutputStream!=null){  
            try {  
                gzipOutputStream.close();  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
        if(in!=null){  
            try {  
                in.close();  
            } catch (IOException e) {  
                e.printStackTrace();  
            }  
        }  
    }  
}  

}  </pre>