Web服务器与客户端三种http交互方式

近期在对接项目时用到http方式与第三方交互数据，由于中间沟通不足导致走了不少弯路，至此特意花了点时间总结服务端与客户端数据交互的方式，本地搭建两个项目一个作为服务端，一个作为客户端。post可以有两种方式：一种与get一样，将请求参数拼接在url后面，这种服务端就以request.getParameter获取内容；另一种以流的方式写入到http链接中，服务端再从流中读取数据，在HttpURlConnection中分别用到了GET、POST请求方式，HttpClient以及commons-httpClient均以POST请求为例。

[b]服务端代码：[/b]

package com.lutongnet.server;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* Servlet implementation class Server_ccy
*/
@WebServlet("/Server_ccy")
public class Server_ccy extends HttpServlet {
private static final long serialVersionUID = 1L;

/**
* @see HttpServlet#HttpServlet()
*/
public Server_ccy() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html;charset=utf-8");
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
System.out.println("server-------doGet..start.");
String name = request.getParameter("name");
String password = request.getParameter("password");
System.out.println("server-------params:"+name+":"+password);
System.out.println("server-------doGet..end.");
PrintWriter out = response.getWriter();
out.print("{\"姓名\":\"陈昌圆\"}");
out.flush();
out.close();
//response.getWriter().append("server_get_info:").append("Served at: ").append(request.getContextPath());
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//doGet(request, response);
response.setContentType("application/json;charset=utf-8");
request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");
System.out.println("server-------doPost..start.");
System.out.println("ContentType---->"+response.getContentType());
System.out.println("queryString---->"+request.getQueryString());
String name = request.getParameter("name");
System.out.println("name---->"+name);
//String password = request.getParameter("password");
//System.out.println("server-------params:"+name+":"+password);
StringBuffer sb = new StringBuffer("");
String str;
BufferedReader br = new BufferedReader(new InputStreamReader(request.getInputStream()));
if((str = br.readLine()) != null){
sb.append(str);
}
System.out.println("从客户端获取的参数："+sb);

System.out.println("server-------doPost..end.");
PrintWriter out = response.getWriter();
out.print("{\"姓名\":\"陈昌圆\"}");
out.flush();
out.close();
}

}

客户端代码：

1.HttpURLConnection：主要详细分析GET与POST两种请求方式，我们项目中的api就是用的这种

package com.lutongnet.HttpURLConnection;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Date;

public class HttpURLConnectionTest {

public static void main(String[] args) {
String url = "http://localhost:7373/ccy_server/ccy";
//String params = "name=ccy&password=123";
String params = "{\"name\":\"陈昌圆\",\"password\":\"123\"}";
try {
String result = httpGetOrPost("POST", url, params);
System.out.println("client---result:"+result);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
public static String httpGetOrPost(String type, String url, String params) throws Exception{
//get请求通过url传参（post可以通过url传参也可以将参数写在http正文传参）
if("GET".equals(type)){
if(url.contains("?")){
url += "&" + params;
}else{
url += "?" + params;
}
}
System.out.println("请求地址：" + url);
System.out.println("请求参数：" + params);
URL u = new URL(url);
/*
* 查看URL API 发现 openConnection方法返回为URLConnection
* HttpURLConnection为URLConnection的子类，有其更多的实现方法，
* 通常将其转型为HttpURLConnection
* */
HttpURLConnection httpConn = (HttpURLConnection) u.openConnection();
//设置请求方式  默认是GET
httpConn.setRequestMethod(type);
//写 默认均为false，GET不需要向HttpURLConnection进行写操作
if("POST".equals(type)){
httpConn.setDoOutput(true);
}
httpConn.setDoInput(true);//读 默认均为true，HttpURLConnection主要是用来获取服务器端数据 肯定要能读
httpConn.setAllowUserInteraction(true);//设置是否允许用户交互  默认为false
httpConn.setUseCaches(false);//设置是否缓存
httpConn.setConnectTimeout(5000);//设置连接超时时间 单位毫秒 ms
httpConn.setReadTimeout(5000);//设置访问超时时间
//setRequestProperty主要设置http请求头里面的相关属性
httpConn.setRequestProperty("user-agent", "Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.31 (KHTML, like Gecko) Chrome/26.0.1410.64 Safari/537.31");
httpConn.setRequestProperty("accept", "*/*");
httpConn.setRequestProperty("Content-Type", "application/json");
//开启连接
httpConn.connect();
//post方式在建立连接后把头文件内容从连接的输出流中写入
if("POST".equals(type)){
//在调用getInputStream()方法中会检查连接是否已经建立，如果没有建立，则会调用connect()
OutputStreamWriter out = new OutputStreamWriter(httpConn.getOutputStream(), "utf-8");
out.write(params);//将数据写入缓冲流
out.flush();//将缓冲区数据发送到接收方
out.close();
}
System.out.println("httpcode:"+httpConn.getResponseCode());
//读取响应，现在开始可以读取服务器反馈的数据
BufferedReader br = new BufferedReader(new InputStreamReader(httpConn.getInputStream(), "utf-8"));
StringBuffer sb = new StringBuffer("");
String str;
while((str = br.readLine()) != null){
sb.append(str);
}
System.out.println(new Date()+"---响应："+sb);
br.close();
httpConn.disconnect();
return sb.toString();
}

}

get请求运行结果

客户端：



服务端：



post请求运行结果

客户端：



服务端：



2.DefaultHttpClient：需要导入三个包，httpclient-4.1.jar,httpcode-4.1.jar,commons-logging-1.1.1.jar,doPost方法是直接可以请求https，doPost2为的http方式，日后若有需要对接第三方接口需要https协议可以参考doPost方法

package com.lutongnet.HttpClient;

import java.security.cert.CertificateException;
public class HttpClientDemo {

public static void main(String[] args) {
HttpClientDemo hct = new HttpClientDemo();
String url = "http://localhost:7373/ccy_server/ccy";
Map<String, String> map = new HashMap<String, String>();
map.put("name", "ccy");
map.put("password", "123");
String charset = "utf-8";
String result = hct.doPost(url, map, charset);
System.out.println("1.获取服务器端数据为："+result);
String params = "{\"name\":\"陈昌圆\",\"password\":\"123\"}";
String result2 = hct.doPost2(url, params);
System.out.println("2.获取服务器端数据为："+result2);
}
public String doPost2(String url, String content) {
System.out.println("请求地址：" + url);
System.out.println("请求参数：" + content);
String charsetName = "utf-8";
DefaultHttpClient httpclient = null;
HttpPost post = null;
try {
httpclient = new DefaultHttpClient();
post = new HttpPost(url);
post.setHeader("Content-Type", "application/json;charset=" + charsetName);
post.setEntity(new StringEntity(content, charsetName));
HttpResponse response = httpclient.execute(post);
HttpEntity entity = response.getEntity();
String rsp = EntityUtils.toString(entity, charsetName);
System.out.println("返回参数： "+rsp);
return rsp;
} catch (Exception e) {
throw new RuntimeException(e);
} finally {
try {
httpclient.getConnectionManager().shutdown();
} catch (Exception ignore) {}
}

}
public String doPost(String url,Map<String,String> map,String charset){
HttpClient httpClient = null;
HttpPost httpPost = null;
String result = null;
try{
httpClient = new SSLClient();
httpPost = new HttpPost(url);
//设置参数
List<NameValuePair> list = new ArrayList<NameValuePair>();
Iterator iterator = map.entrySet().iterator();
while(iterator.hasNext()){
Entry<String,String> elem = (Entry<String, String>) iterator.next();
list.add(new BasicNameValuePair(elem.getKey(),elem.getValue()));
}
if(list.size() > 0){
UrlEncodedFormEntity entity = new UrlEncodedFormEntity(list,charset);
httpPost.setEntity(entity);
}
HttpResponse response = httpClient.execute(httpPost);
if(response != null){
HttpEntity resEntity = response.getEntity();
if(resEntity != null){
result = EntityUtils.toString(resEntity,charset);
}
}
}catch(Exception ex){
ex.printStackTrace();
}
return result;
}
class SSLClient extends DefaultHttpClient{
public SSLClient() throws Exception{
super();
SSLContext ctx = SSLContext.getInstance("TLS");
X509TrustManager tm = new X509TrustManager() {
@Override
public void checkClientTrusted(X509Certificate[] chain,
String authType) throws CertificateException {
}
@Override
public void checkServerTrusted(X509Certificate[] chain,
String authType) throws CertificateException {
}
@Override
public X509Certificate[] getAcceptedIssuers() {
return null;
}
};
ctx.init(null, new TrustManager[]{tm}, null);
SSLSocketFactory ssf = new SSLSocketFactory(ctx,SSLSocketFactory.ALLOW_ALL_HOSTNAME_VERIFIER);
ClientConnectionManager ccm = this.getConnectionManager();
SchemeRegistry sr = ccm.getSchemeRegistry();
sr.register(new Scheme("https", 443, (SchemeSocketFactory) ssf));
}
}
}

post请求运行结果

客户端：



服务端：



3.commons-httpclient：需要导入两个包，commons-httpclient-3.0.jar，commons-codec-1.7.jar，这种方式是最简洁的，前后不到10行代码就解决了，不过需要注意的是设置正文编码，5种方式都可行，这种将参数拼接在http正文中，在服务端可以利用request.getParameter()方法获取参数，也可以用request.getInputStream()流的方式获取参数（这种方式如果参数中有中文的话，暂时没有找到解决乱码的方法）

package com.lutongnet.commonHttpclient;

import java.util.ArrayList;
import java.util.List;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;

public class CommonHttpClient {
public static void main(String[] args) {
String url = "http://localhost:7373/ccy_server/ccy";
List<String> params = new ArrayList<String>();
params.add("陳昌圓");
params.add("123");
CommonHttpClient chc = new CommonHttpClient();
String result = chc.getPostMethod(url, params);
System.out.println("commonHttpClient---->从服务端获取的数据：" + result);
}
private String getPostMethod(String url, List<String> params) {
String result = null;
HttpClient httpClient = new HttpClient();
PostMethod postMethod = new PostMethod(url);
//httpClient.getParams().setContentCharset("utf-8");
//httpClient.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, "utf-8");
//postMethod.addRequestHeader("Content-type","application/x-www-form-urlencoded; charset=UTF-8");
//postMethod.addRequestHeader("Content-Type", PostMethod.FORM_URL_ENCODED_CONTENT_TYPE
//        + "; charset=utf-8");
postMethod.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET,
"utf-8");
postMethod.addParameter("name", params.get(0));
postMethod.addParameter("password", params.get(1));
try {
httpClient.executeMethod(postMethod);
result = postMethod.getResponseBodyAsString();
System.out.println("result:" + result);
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
/*class ccyPostMethod extends PostMethod {
public ccyPostMethod(String url) {
super(url);
}

@Override
public String getRequestCharSet() {
return "utf-8";
}
}*/

}

post请求运行结果

客户端：



服务端：