JAVA 调用HTTP接口POST或GET实现方式（转）

  HTTP是一个客户端和服务器端请求和应答的标准（TCP），客户端是终端用户，服务器端是网站。通过使用Web浏览器、网络爬虫或者其它的工具，客户端发起一个到服务器上指定端口（默认端口为80）的HTTP请求。

具体POST或GET实现代码如下：

package com.yoodb.util;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

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

public class HttpConnectUtil {
    
    private static String DUOSHUO_SHORTNAME = "yoodb";//多说短域名 ****.yoodb.****
    private static String DUOSHUO_SECRET = "xxxxxxxxxxxxxxxxx";//多说秘钥
    
   /**
 * 
 * @Title:getToken
 * @Description:(get方式调用http接口获取token)
 * @param url
 * @return
 * @throws Exception
 * @author zzq
 */
    public static String getToken(String url) throws Exception {
  String responseMsg = "";
  String access_token = "";
  HttpClient httpClient = new HttpClient();
  GetMethod getMethod = new GetMethod(url);
  getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER,
    new DefaultHttpMethodRetryHandler());
  try {
   httpClient.executeMethod(getMethod);
   ByteArrayOutputStream out = new ByteArrayOutputStream();
   InputStream in = getMethod.getResponseBodyAsStream();
   int len = 0;
   byte[] buf = new byte[1024];
   while ((len = in.read(buf)) != -1) {
    out.write(buf, 0, len);
   }
   responseMsg = out.toString("UTF-8");
   JSONObject obj = JSONObject.fromObject(responseMsg);
   System.out.print(obj);
   access_token = obj.getString("access_token");
  } catch (HttpException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } finally {
   getMethod.releaseConnection();// 释放连接
  }
  return access_token;
 }

    /**
     * post方式
     * @param url
     * @param code
     * @param type
     * @author www.yoodb.com
     * @return
     */
    public static String postHttp(String url,String code,String type) {
        String responseMsg = "";
        HttpClient httpClient = new HttpClient();
        httpClient.getParams().setContentCharset("GBK");
        PostMethod postMethod = new PostMethod(url);
        postMethod.addParameter(type, code);
        postMethod.addParameter("client_id", DUOSHUO_SHORTNAME);
        postMethod.addParameter("client_secret", DUOSHUO_SECRET);
        try {
            httpClient.executeMethod(postMethod);
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            InputStream in = postMethod.getResponseBodyAsStream();
            int len = 0;
            byte[] buf = new byte[1024];
            while((len=in.read(buf))!=-1){
                out.write(buf, 0, len);
            }
            responseMsg = out.toString("UTF-8");
        } catch (HttpException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            postMethod.releaseConnection();
        }
        return responseMsg;
    }
}

1、下面说一下多说单点登录（SSO）获取access_token访问多说API的凭证。

多说单点登录（SSO），授权结束后跳转回在sso中设置的login地址，注意这时候的URL带上了code参数，通过code获取access_token访问多说API的凭证，具体实现代码如下：

public Map<String, String> getUserToken(String code){
    String url = "http://api.duoshuo.com/oauth2/access_token";
    String response = HttpConnectUtil.postHttp(url, code, "code");
    System.out.println(response);
    Gson gson = new Gson();
    Map<String, String> retMap = gson.fromJson(response,new TypeToken<Map<String, String>>() {}.getType()); 
    return retMap;
}

返回参数是一个JSON串，包含user_id和access_token，user_id是该用户在多说的ID，access_token是访问多说API的凭证，处理成Map集合方便使用。

2、如果获取多说的用户信息，根据上一步获得的多说用户user_id来获取用户的具体信息，详情代码如下：

public Map getProfiletMap(String userId){
    String url = "http://api.duoshuo.com/users/profile.json?user_id="+userId;
    String response = HttpConnectUtil.getHttp(url);
    response = response.replaceAll("\\", "");
    System.out.println(response);
    Gson gson = new Gson();
    Map profile = gson.fromJson(response, Map.class);
    return profile;
}

上述使用了Google处理json数据的jar，如果对Gson处理json数据的方式不很了解，参考地址：http://www.yoodb.com/article/display/1033

返回的数据格式如下：

{
    "response": {
        "user_id": "13504206",
        "name": "伤了心",
        "url": "http://t.qq.com/wdg1115024292",
        "avatar_url": "http://q.qlogo.cn/qqapp/100229475/F007A1729D7BCC84C106D6E4F2ECC936/100",
        "threads": 0,
        "comments": 0,
        "social_uid": {
            "qq": "F007A1729D7BCC84C106D6E4F2ECC936"
        },
        "post_votes": "0",
        "connected_services": {
            "qqt": {
                "name": "伤了心",
                "email": null,
                "avatar_url": "http://app.qlogo.cn/mbloghead/8a59ee1565781d099f3a/50",
                "url": "http://t.qq.com/wdg1115024292",
                "description": "没劲",
                "service_name": "qqt"
            },
            "qzone": {
                "name": "?郁闷小佈?",
                "avatar_url": "http://q.qlogo.cn/qqapp/100229475/F007A1729D7BCC84C106D6E4F2ECC936/100",
                "service_name": "qzone"
            }
        }
    },
    "code": 0
}

获取的用户信息不方便查看，建议格式化一下，Json校验或格式化地址：http://www.yoodb.com/toJson，返回数据参数说明：

code int 一定返回

结果码。0为成功。失败时为错误码。

errorMessage strin

错误消息。当code不为0时，返回错误消息。

response object

json对象。当code为0时，返回请求到的json对象。

来源：http://www.yoodb.com/article/display/1034