客户端HttpClient处理 Servlet Gzip

　　服务端采用gzip对文本内容进行压缩处理，客户端使用HttpClient获取数据并进行gzip解压缩。

一： 服务端

public class GzipTestServlet extends HttpServlet {

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setHeader("Cache-Control", "no-cache");
response.setContentType("text/html;charset=UTF-8");

String str = "中文测试this is a test!";

if (isGzipSupport(request)) {//支持gzip
response.setHeader("Content-Encoding", "gzip");
OutputStream os = response.getOutputStream();
GZIPOutputStream gs = new GZIPOutputStream(os);
gs.write(str.getBytes("UTF-8"));//解决中文乱码问题
gs.finish();
gs.close();
os.close();
} else {
PrintWriter out = response.getWriter();
out.write(str);
out.flush();
out.close();
}
}

/**
* 判断客户端是否要求进行gzip压缩处理
* @param request
* @return
*/
private boolean isGzipSupport(HttpServletRequest request) {
String headEncoding = request.getHeader("accept-encoding");
return (headEncoding != null && (headEncoding.indexOf("gzip") != -1));
}

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}

@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
}

二：客户端

　　采用HttpClient3.1。

（1）UngzipPostMethod.java

/**
* 继承PostMethod重写getResponseBodyAsString方法支持Gzip解压缩*/
public class UngzipPostMethod extends org.apache.commons.httpclient.methods.PostMethod{
public UngzipPostMethod(String uri){
super(uri);
}

@Override
public String getResponseBodyAsString() throws IOException {
GZIPInputStream gzin;
if(getResponseBody()!=null ||getResponseStream() != null ){
if(getResponseHeader("Content-Encoding") != null && getResponseHeader("Content-Encoding").getValue().toLowerCase().indexOf("gzip") != -1) {
InputStream is = getResponseBodyAsStream();
gzin = new GZIPInputStream(is);

InputStreamReader isr = new InputStreamReader(gzin,getResponseCharSet());

BufferedReader br = new BufferedReader(isr);
StringBuilder sb = new StringBuilder();
String tmp;
while((tmp = br.readLine())!=null){
sb.append(tmp);
sb.append("\r\n");
}
br.close();
isr.close();
return sb.toString();
}else{
//否则正常返回
return super.getResponseBodyAsString();
}
}else{
return null;
}
}
}

（2）HttpUtil.java

public class HttpUtil {
/**
* 获取到解压缩的内容
* @param url
* @param list
* @return
*/
public String postGzipRequest(String url, List<NameValuePair> list){
HttpClient client = new HttpClient();
UngzipPostMethod post = new UngzipPostMethod(url);
post.setRequestHeader("Accept-Encoding", "gzip, deflate");
post.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, "UTF-8");
StringBuilder sb = new StringBuilder();

if(list!=null){
int len = list.size();
NameValuePair[] params = new NameValuePair[len];
for(int i=0; i<len; i++){
params[i] = list.get(i);
}
post.setRequestBody(params);
}
try {
//执行post
int statusCode = client.executeMethod(post);

if (statusCode == HttpStatus.SC_OK) {
sb.append(post.getResponseBodyAsString());
}

} catch (IOException ex) {
java.util.logging.Logger.getLogger(HttpUtil.class.getName()).log(Level.SEVERE, null, ex);
}
return sb.toString();
}
}

（3）Test.java

public class Test {
public static void main(String args[]){
HttpUtil httpUtil = new HttpUtil();
String url = "http://localhost:8080/tsmanager/GzipTestServlet.do";
System.out.println("内容："+httpUtil.postGzipRequest(url, null));
}
}