Java：post请求

文章来源:https://www.cnblogs.com/hello-tl/p/9140870.html 

0.post请求返回json

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

public class GetHttpRequest{
  /**
     *  POST 请求
     * @param path
     * @param post
     * @return
     */
    public static JsonObject SendPostJsonObject(String path,String post){
        URL url = null;
        try {
            url = new URL(path);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");// 提交模式
            // conn.setConnectTimeout(10000);//连接超时 单位毫秒
            // conn.setReadTimeout(2000);//读取超时 单位毫秒
            // 发送POST请求必须设置如下两行
            httpURLConnection.setDoOutput(true);
            httpURLConnection.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            PrintWriter printWriter = new PrintWriter(httpURLConnection.getOutputStream());
            // 发送请求参数
            printWriter.write(post);//post的参数 xx=xx&yy=yy
            // flush输出流的缓冲
            printWriter.flush();
            //开始获取数据
            BufferedInputStream bis = new BufferedInputStream(httpURLConnection.getInputStream());
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            int len;
            byte[] arr = new byte[1024];
            while((len=bis.read(arr))!= -1){
                bos.write(arr,0,len);
                bos.flush();
            }
            bos.close();
            JsonParser parse = new JsonParser();
            return (JsonObject)parse.parse(bos.toString("utf-8"));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    } 
}

1.post请求返回 String

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.List;
import java.util.Map;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;

public class GetHttpRequest{
  /**
     * 向指定 URL 发送POST方法的请求
     * 
     * @param url 发送请求的 URL
     * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String SendPostToString(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent",
                    "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(conn.getInputStream(),"utf-8"));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            //System.out.println("发送 POST 请求出现异常！"+e);
            e.printStackTrace();
        }
        //使用finally块来关闭输出流、输入流
        finally{
            try{
                if(out!=null){
                    out.close();
                }
                if(in!=null){
                    in.close();
                }
            }
            catch(IOException ex){
                ex.printStackTrace();
            }
        }
        return result;
    }    
}

 文章来源:https://www.cnblogs.com/hello-tl/p/9140870.html