Java 通过别人提供的http接口获取信息

package com.web.util;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

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

public class HttpRequestUtil {
	
	public static String addUrl(String head, String tail) {
		if (head.endsWith("/")) {
			if (tail.startsWith("/")) {
				return head.substring(0, head.length() - 1) + tail;
			} else {
				return head + tail;
			}
		} else {
			if (tail.startsWith("/")) {
				return head + tail;
			} else {
				return head + "/" + tail;
			}
		}
	}

	public synchronized static String postData(String url, Map<String, String> params, String codePage) throws Exception {

		final HttpClient httpClient = new HttpClient();
		httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(10 * 1000);
		httpClient.getHttpConnectionManager().getParams().setSoTimeout(10 * 1000);

		final PostMethod method = new PostMethod(url);
		if (params != null) {
			method.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET, codePage);
			method.setRequestBody(assembleRequestParams(params));
		}
		String result = "";
		try {
			httpClient.executeMethod(method);
			result = new String(method.getResponseBody(), codePage);
		} catch (final Exception e) {
			throw e;
		} finally {
			method.releaseConnection();
		}
		return result;
	}

	public synchronized static String postData(String url, String codePage) throws Exception {
		final HttpClient httpClient = new HttpClient();
		httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(10 * 1000);
		httpClient.getHttpConnectionManager().getParams().setSoTimeout(10 * 1000);

		final GetMethod method = new GetMethod(url);
		String result = "";
		try {
			httpClient.executeMethod(method);
			result = new String(method.getResponseBody(), codePage);
		} catch (final Exception e) {
			throw e;
		} finally {
			method.releaseConnection();
		}
		return result;
	}

	/**
	 * 组装http请求参数
	 * 
	 * @param params
	 * @param menthod
	 * @return
	 */
	private synchronized static NameValuePair[] assembleRequestParams(Map<String, String> data) {
		final List<NameValuePair> nameValueList = new ArrayList<NameValuePair>();

		Iterator<Map.Entry<String, String>> it = data.entrySet().iterator();
		while (it.hasNext()) {
			Map.Entry<String, String> entry = (Map.Entry<String, String>) it.next();
			nameValueList.add(new NameValuePair((String) entry.getKey(), (String) entry.getValue()));
		}

		return nameValueList.toArray(new NameValuePair[nameValueList.size()]);
	}

}

　　

 

 

1.引入相应的jar包（.net）

2.创建连接

3.发送post请求

4.读取响应

5.断开链接

注意：

       传参：1.可以在链接后边加参数（不推荐）

               2.一般都是把参数封装成一个json字符串，然后发送过去。out.writeBytes(jsonStr);

例子：

    	
		String urlStr = "http://my.b2b.hc360.com/my/turbine/template/firstview,corinfo4chat.html?username=jinjiangjiayi";
//		String str = new PostHttpClient().postHttp(url1, tradeId);
        
        StringBuffer strBuf = new StringBuffer("");
        try {
            //创建连接
            URL url = new URL(urlStr);
            HttpURLConnection connection = (HttpURLConnection) url
                    .openConnection();
            connection.setDoOutput(true);
            connection.setDoInput(true);
            connection.setRequestMethod("POST");
            connection.setUseCaches(false);
            connection.setInstanceFollowRedirects(true);
            connection.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded");
            
            connection.connect();

            //POST请求
            DataOutputStream out = new DataOutputStream(
                    connection.getOutputStream());

//            out.writeBytes(jsonStr);
            out.flush();
            out.close();

            //读取响应
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String lines;
            while ((lines = reader.readLine()) != null) {
                lines = new String(lines.getBytes(), "utf-8");
                strBuf.append(lines);
            }
            //返回的请求信息
            System.out.println(strBuf);
            reader.close();
            // 断开连接
            connection.disconnect();
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println("++++++++++++++++++++++++");
         System.out.println(strBuf);   
	
	

例子：

package cn.com.speed.busdevelop.util;

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import net.sf.json.JSONObject;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.HttpException;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.commons.httpclient.methods.ByteArrayRequestEntity;
import org.apache.commons.httpclient.methods.EntityEnclosingMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.RequestEntity;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.struts2.ServletActionContext;

import cn.com.speed.busdevelop.action.account.AccountAction;
import cn.com.speed.busdevelop.po.Account;
import cn.com.speed.busdevelop.service.AccountService;
import cn.com.speed.busdevelop.service.impl.AccountServiceImpl;

import com.sdicons.json.mapper.JSONMapper;
import com.sdicons.json.mapper.MapperException;

    
    public static void main(String[] args) {
    	
//    	String urlStr1 = "http://localhost:8080/devp1/account/accountAction!queryListAccount.action?cid=POS101&cmd=201&version=1.0&returnType=json&userId=liangzg&verify=";
//    	new PostHttpClient().postHttp(urlStr1, "");
    	
//    	String tradeId = "140521181509XX030056";
		String urlStr = "http://192.168.12.13:8080/devp1/account/account!queryListAccount.action?cmd=201&verify=813828425fe78f57cb46acddf1edd9e4&userId=houlj1&cid=POS101&returnType=json&version=1.0";
//		String str = new PostHttpClient().postHttp(url1, tradeId);
//		System.out.println(str);
    	System.out.println("--------------------------------------------");
		Map map = new HashMap();
		map.put("cid", "POS101");//系统标识
		map.put("cmd", "201");//命令字
		map.put("version", "1.0");//接口版本
		map.put("returnType", "json");//报文格式
		String md5String = MD5.getSign(map, "123456789", "MD5", "UTF-8");
        
		map.put("userId", "liangzg");
        
//    	map.put("sign", MD5.getSign(map,"123456789", "MD5", "UTF-8"));
        
//    	String urlStr = "http://localhost:8080/devp1/account/accountAction!queryListAccount.action?cid=POS101&cmd=201&version=1.0&returnType=json&userId=liangzg&verify="+md5String;
        String jsonStr = null;
        try {
			jsonStr = JSONMapper.toJSON(map).render(false);
		} catch (MapperException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
//		System.out.println(jsonStr);
		
        StringBuffer strBuf = new StringBuffer("");
        try {
            //创建连接
            URL url = new URL(urlStr);
            HttpURLConnection connection = (HttpURLConnection) url
                    .openConnection();
            connection.setDoOutput(true);
            connection.setDoInput(true);
            connection.setRequestMethod("POST");
            connection.setUseCaches(false);
            connection.setInstanceFollowRedirects(true);
            connection.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded");
            
            connection.connect();

            //POST请求
            DataOutputStream out = new DataOutputStream(
                    connection.getOutputStream());

            out.writeBytes(jsonStr);
            out.flush();
            out.close();

            //读取响应
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    connection.getInputStream()));
            String lines;
            while ((lines = reader.readLine()) != null) {
                lines = new String(lines.getBytes(), "utf-8");
                strBuf.append(lines);
            }
            //返回的请求信息
//            System.out.println(strBuf);
            reader.close();
            // 断开连接
            connection.disconnect();
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println("++++++++++++++++++++++++");
         System.out.println(strBuf);   
            
            
	}

}