xiaoxin 使用Apache HTTPClient，并以JSON为参数进行POST请求

注：这是httpclient4,httpclient4与3用法有很大差别
package org.ssi.util;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import net.sf.json.JSONArray;

import org.apache.commons.lang.exception.ExceptionUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.protocol.HTTP;
import org.apache.http.util.EntityUtils;


public class APIHttpClient {

    //接口地址
    private String apiURL = "" ;
    private Log logger = LogFactory.getLog( this .getClass());
    private static final String pattern = "yyyy-MM-dd HH:mm:ss:SSS" ;
        private HttpClient httpClient = null ;
    private HttpPost method = null ;
    private long startTime = 0L;
    private long endTime = 0L;
    private int status = 0 ;
    /**
     * 接口地址
     * @param url
     */
    public APIHttpClient(String url){

        if (url != null )
        {
            this .apiURL = url;
        }
        if (apiURL != null )
        {
                    httpClient = new DefaultHttpClient();
                    method = new HttpPost(apiURL);

        }
    }

    /**
     * 调用 API
     * @param parameters
     * @return
     */
    public String post(String parameters)
    {
        String body = null ;
                logger.info( "parameters:" + parameters);


        if (method != null & parameters != null  && ! "" .equals(parameters.trim()))
        {
                    JSONArray jsonObject = JSONArray.fromObject(parameters);
                    logger.info( "json:" + jsonObject.toString());
                    try {

                        List<NameValuePair> params= new ArrayList<NameValuePair>();
                        //建立一个NameValuePair数组，用于存储欲传送的参数
                        params.add( new BasicNameValuePair( "data" ,parameters));
                        //添加参数
                        method.setEntity( new UrlEncodedFormEntity(params,HTTP.UTF_8));

                        startTime = System.currentTimeMillis();

                        //设置编码
                        HttpResponse response=httpClient.execute(method);
                        endTime = System.currentTimeMillis();
                        int statusCode = response.getStatusLine().getStatusCode();
                        logger.info( "statusCode:" + statusCode);
                         logger.info( "调用API 花费时间(单位：毫秒)：" + (endTime - startTime));
                        if (statusCode != HttpStatus.SC_OK){
                            logger.error( "Method failed:" +response.getStatusLine());
                            status = 1 ;
                        }

                            //Read the response body
                             body=EntityUtils.toString(response.getEntity());

            } catch (IOException e){
                //发生网络异常
                logger.error( "exception occurred!\n" +ExceptionUtils.getFullStackTrace(e));
                //网络错误
                status = 3 ;
            }
                    finally {
                        logger.info( "调用接口状态：" + status);
                    }


        }
        return body;
    }

    /**
     * 0.成功 1.执行方法失败 2.协议错误 3.网络错误
     * @return the status
     */
    public int getStatus() {
        return status;
    }

    /**
     * @param status the status to set
     */
    public void setStatus( int status) {
        this .status = status;
    }
    /**
     * @return the startTime
     */
    public long getStartTime() {
        return startTime;
    }
    /**
     * @return the endTime
     */
    public long getEndTime() {
        return endTime;
    }
}

原文地址：http://www.oschina.net/code/snippet_242695_20850