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Android Gzip压缩和解压缩文件

2016-05-26 11:19 489 查看

为了节省流量用到了Gzip压缩文件。

参考此链接中的代码https://gist.github.com/ansjsun/5791394

importjava.io.ByteArrayInputStream;


	import java.io.ByteArrayOutputStream;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.util.zip.GZIPInputStream;
	import java.util.zip.GZIPOutputStream;

	public class StringZip {
	public static void main(String[] args) throws Exception {
	StringBuilder value = new StringBuilder() ;
	for (int i=0; i< 100; i++) {
	value.append("java gzip 压缩测试");
	}
	//字符串压缩为byte数组
	byte[] values = value.toString().getBytes() ;
	System.out.println("解压前大小"+values.length);
	values = compress(values) ;
	System.out.println("解压后大小"+values.length);
	//把压缩后的byte数组转为字符串
	String str = new String(values,"iso8859-1") ;

	//传输字符串
	System.out.println(str);

	//将接受到的字符串转换为byte数组
	values = str.getBytes("iso8859-1") ;
	//解压缩这个byte数组
	values = decompress(values) ;
	System.out.println(newString(values,"utf-8"));

	}

	/**
	* 数据解压缩
	*
	* @param data
	* @return
	* @throws Exception
	*/
	public static byte[] decompress(byte[] data) throws Exception {
	ByteArrayInputStream bais = new ByteArrayInputStream(data);
	ByteArrayOutputStream baos = new ByteArrayOutputStream();

	// 解压缩

	decompress(bais, baos);

	data = baos.toByteArray();

	baos.flush();
	baos.close();

	bais.close();

	return data;
	}

	/**
	* 数据解压缩
	*
	* @param is
	* @param os
	* @throws Exception
	*/
	public static void decompress(InputStream is, OutputStream os)
	throws Exception {

	GZIPInputStream gis = new GZIPInputStream(is);

	int count;
	byte data[] = new byte[BUFFER];
	while ((count = gis.read(data, 0, BUFFER)) != -1) {
	os.write(data, 0, count);
	}

	gis.close();
	}

	public static byte[] compress(byte[] data) throws Exception {
	ByteArrayInputStream bais = new ByteArrayInputStream(data);
	ByteArrayOutputStream baos = new ByteArrayOutputStream();

	// 压缩
	compress(bais, baos);

	byte[] output = baos.toByteArray();

	baos.flush();
	baos.close();

	bais.close();

	return output;
	}
	static final int BUFFER = 10240 ;
	/**
	* 数据压缩
	*
	* @param is
	* @param os
	* @throws Exception
	*/
	public static void compress(InputStream is, OutputStream os)
	throws Exception {

	GZIPOutputStream gos = new GZIPOutputStream(os);

	int count;
	byte data[] = new byte[BUFFER];
	while ((count = is.read(data, 0, BUFFER)) != -1) {
	gos.write(data, 0, count);
	}

	gos.finish();

	gos.flush();
	gos.close();
	}

	}

以下是我的部分代码片段函数中压缩了一个 xml文件，

public void sendmessage2() {
try {
OutputStream out =  socket.getOutputStream();
StringBuilder xml = new StringBuilder();
xml.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>");
xml.append("<CMD ID=\"0\" Cmd=\"1\" Cla=\"17\" Name=\"js6\">");
xml.append("<PARA Data=\"123456\" Para=\"js4\"/>\n");
xml.append("</CMD>");

//字符串压缩为byte数组
byte[] values ;
values = compress(xml.toString().getBytes("utf-8")) ;
//传输字符串
out.write(values);

Message m = new Message();
m.what = 1;
handler.sendMessage(m);
} catch (Exception e) {
e.printStackTrace();
Message m = new Message();
m.what = 2;
handler.sendMessage(m);
}
}

//解压代码

public void receievmessage(){
try{
while(true){
DataInputStream input = new DataInputStream(socket.getInputStream());
byte[] buffer;
//读取input中没有读取的字节
buffer = new byte[input.available()];
int len;
if(buffer.length != 0){
System.out.println("获取到字节");
GZIPInputStream gzip =new GZIPInputStream(input);
// 读取缓冲区
len= gzip.read(buffer);
System.out.println("接收的长度: "+len);
char[] tChars=new char[300];
for(int i=0;i<len;i++)
{   tChars[i]=(char)buffer[i];  }
StringBuffer  tStringBuf=new StringBuffer ();
tStringBuf.append(tChars);

System.out.println("接收的内容是: "+ tStringBuf);
// System.out.println("接收的长度: "+buffer);
// String msg = new String(buffer, "utf-8");//注意转码，不然中文会乱码。
//  Message m = new Message();
//  m.what = 3;
//  m.obj = msg;
//handler.sendMessage(m);
}
}

}catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
Message m = new Message();
m.what = 2;
handler.sendMessage(m);
}
}

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标签： android github socket android studio gzip

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