HttpURLConnection用流传递参数

以前做过HttpURLConnection传递参数的例子，这次用流来实现，看下面的这个例子。

工具类：

package com.hljw.health.y100.job;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.Charset;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import com.alibaba.fastjson.JSON;
import com.hljw.health.y100.pojo.CommunityParametersObject;
import com.hljw.util.DateUtil;


public class HttpClient {
	private static String _default_encoding = Charset.defaultCharset().name();
//1.发送请求
	public static String getResopnseData(String data,String url) {
		try {
			HttpURLConnection connection = getURL(url);

			return sendRequest(connection, data);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

//创建httpconn对象
	private static HttpURLConnection getURL(String wsUrl) throws Exception {
		URL url = new URL(wsUrl);
		HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
		httpConn.setRequestProperty("content-type", "text/html");//参数穿不过去请设置这一条
		httpConn.setRequestProperty("Accept-Charset", "utf-8");
		httpConn.setRequestMethod("POST");
		httpConn.setUseCaches(false);
		httpConn.setDoInput(true);
		httpConn.setDoOutput(true);
		Charset.availableCharsets();
		httpConn.setInstanceFollowRedirects(true);
		return httpConn;
	}

//发送请求参数，并得到服务端的返回信息
	private static String sendRequest(HttpURLConnection conn, String data)
			throws Exception {
		conn.getOutputStream().write(data.getBytes("utf-8"));
		conn.getOutputStream().flush();
		conn.getOutputStream().close();
		return response(conn);

	}

	private static String response(HttpURLConnection conn) throws Exception {

		StringBuffer info = new StringBuffer();
		BufferedReader reader = new BufferedReader(new InputStreamReader(conn
				.getInputStream(),"utf-8"));
		// BufferedReader reader = new BufferedReader(new
		// InputStreamReader(conn.getInputStream()));
		// conn.connect();
		System.out.println("=============================");
		System.out.println("Contents of post request");
		System.out.println("=============================");

		String line = reader.readLine();
		while (line != null) {
			info.append(line);

			line = reader.readLine();
		}
		System.out.println("=============================");
		System.out.println("Contents of post request ends");
		System.out.println("=============================");
		reader.close();

		String ecod = conn.getContentEncoding();
		if (ecod == null) {
			ecod = _default_encoding;
		}

		String resData = new String(java.net.URLDecoder.decode(info.toString(),
				"UTF-8").getBytes());// ecod
		conn.disconnect();
		return resData;
		// Object obj = getResult(resData);
	}

}

 

服务端：

服务端是一个servlet用来接收发过来的参数处理业务逻辑，向客户端返回信息

package com.hljw.health.y100.service.pinstitutions;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.alibaba.fastjson.JSON;
import com.hljw.health.plat.service.pinstitutions.PInstitutionsService;
import com.hljw.util.SpringUtil;
import com.hljw.util.StringUtil;

public class PInstitutionsServiceServlet extends HttpServlet{
	private PInstitutionsService pInstitutionsService = (PInstitutionsService) SpringUtil.getBean("pInstitutionsService");
	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		this.doPost(request, response);
	}

	@Override
	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		// TODO Auto-generated method stub
		System.out.println("ok");
		System.out.println(pInstitutionsService);
		
		ResultObject res=parseResult(request);//解析参数
		System.out.println(res);
		callBackPrint("哈哈，好的呢？dd", response);//想客户端打印信息
		
//		pInstitutionsService.getPInstitutionsByOrgCode(institutions_code);
	}
	
	/**
	 * 解析参数、回调的内容
	 * @param request
	 * @return
	 * @throws IOException
	 */
	private ResultObject parseResult(HttpServletRequest request) throws IOException{
		StringBuffer info = new StringBuffer();
		BufferedReader reader = new BufferedReader(new InputStreamReader(request.getInputStream(),"UTF-8")); //防止中文乱码
		String line = reader.readLine();
		while (!StringUtil.isBlank(line)) {
			info.append(line);
			line = reader.readLine();
		}
		ResultObject obj = null;
		if(info.length()>0){
			obj = JSON.parseObject(info.toString(), ResultObject.class);
		}
		return obj;
	}
	
	/**
	 * 回调打印信息
	 * @author hjh
	 * @return
	 */
	private void callBackPrint(String content,HttpServletResponse response) throws IOException{
		/*
		 * 在调用getWriter之前未设置编码(既调用setContentType或者setCharacterEncoding方法设置编码),
		 * HttpServletResponse则会返回一个用默认的编码(既ISO-8859-1)编码的PrintWriter实例。这样就会
		 * 造成中文乱码。而且设置编码时必须在调用getWriter之前设置,不然是无效的。
		 * */
		response.setContentType("text/html;charset=UTF-8");
		response.setCharacterEncoding("UTF-8");
		PrintWriter out = response.getWriter();
		//JSON在传递过程中是普通字符串形式传递的，这里简单拼接一个做测试
		out.print(content);
		out.flush();
		out.close();
	}
}

 测试类

package com.hljw.health.y100.service.pinstitutions;

import com.alibaba.fastjson.JSON;
import com.hljw.health.y100.job.HttpClient;

public class Test {
	public static void main(String[] args) {
		System.out.println("rrrr");
		ResultObject res=new ResultObject();
		res.setStatus("1");
		res.setOpear("check中国");
		
		String resStr = HttpClient.getResopnseData(JSON.toJSONString(res),"http://localhost:8080/healthplat/pInstitutions.action");//发送数据，并得到服务端返回的信息
		System.out.println("**********"+resStr);
	}
}

 参数的传递用的json格式的数据，当然你也可以用其他的格式，值得注意的是

1.参数如果在服务端无法接收是因为在发送的方法里面没有设定，这个问题困扰了我很久，因为无论是servlet，还是struts1,struts2,都没有设置这一个，所以自己要设置一下。

 

httpConn.setRequestProperty("content-type", "text/html");//参数穿不过去请设置这一条

2.无论什么时候中文出现乱码是因为编码不统一，注意以下几个地方。

a.工具类里面发送的时候要设置中文utf-8编码

b.工具类接收服务端回调请求要设置UTF-8编码

c.服务端servlet接收参数流要用utf-8编码

d.服务端servlet想客户端打印字符的时候要设置UTF-8编码。