用Java实现GET,POST请求

桃扇骨 2022-05-24 02:25 220阅读 0赞

首先，创建一个HttpRequest工具类

package com.bonc.common.utils;
    
    import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.OutputStreamWriter;
    import java.io.PrintWriter;
    import java.net.URL;
    import java.net.URLConnection;
    import java.util.List;
    import java.util.Map;
    
    
    
    
    
    
    public class HttpRequest {
        /**
         * 向指定URL发送GET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 URL 所代表远程资源的响应结果
         */
        public static String sendGet(String url, String param) {
            String result = "";
            BufferedReader in = null;
            try {
                String urlNameString = url + "?" + param;
                URL realUrl = new URL(urlNameString);
                // 打开和URL之间的连接
                URLConnection connection = realUrl.openConnection();
                // 设置通用的请求属性
                connection.setRequestProperty("accept", "*/*");
                connection.setRequestProperty("connection", "Keep-Alive");
                connection.setRequestProperty("user-agent",
                        "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
                // 建立实际的连接
                connection.connect();
                // 获取所有响应头字段
                Map<String, List<String>> map = connection.getHeaderFields();
                // 遍历所有的响应头字段
                for (String key : map.keySet()) {
                    System.out.println(key + "--->" + map.get(key));
                }
                // 定义 BufferedReader输入流来读取URL的响应
                in = new BufferedReader(new InputStreamReader(
                        connection.getInputStream()));
                String line;
                while ((line = in.readLine()) != null) {
                    result += line;
                }
            } catch (Exception e) {
                System.out.println("发送GET请求出现异常！" + e);
                e.printStackTrace();
            }
            // 使用finally块来关闭输入流
            finally {
                try {
                    if (in != null) {
                        in.close();
                    }
                } catch (Exception e2) {
                    e2.printStackTrace();
                }
            }
            return result;
        }
    
        /**
         * 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 sendPost(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", "application/json, text/javascript, */*; q=0.01");
                conn.setRequestProperty("Accept-Encoding", "gzip, deflate");
                conn.setRequestProperty("Connection", "keep-alive");
                conn.setRequestProperty("Accept-Language", "zh-CN,zh;q=0.8");
                conn.setRequestProperty("Content-Length", "80");
                conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
                conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/52.0.2743.116 Safari/537.36");
                		
                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
                OutputStreamWriter outWriter = new OutputStreamWriter(conn.getOutputStream(), "utf-8");  
                out = new PrintWriter(outWriter);
                // 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;
        }   
        
        public static void main(String[] args) {
            //发送 GET 请求
           /* String s=HttpRequest.sendGet("http://localhost:6144/Home/RequestString", "key=123&v=456");
            System.out.println(s);*/
            
            //发送 POST 请求
           /* String sr=HttpRequest.sendPost("http://www.cheshouye.com/api/weizhang/get_all_config","");
           
            JSONObject jsStr = JSONObject.fromObject(sr);
            JSONArray jsonarray = jsStr.getJSONArray("configs");
          
            for(int i=0;i<jsonarray.size();i++){
            	JSONObject ob1=(JSONObject)jsonarray.get(i);
            	Integer provinceId=ob1.getInt("provice_id");
            	String provinceName=ob1.getString("provice_name");
            	String provinceShortName=ob1.getString("provice_short_name");
            	JSONArray jsonarray2 = ob1.getJSONArray("citys");
            	
            	
            }
            System.out.println(jsonarray);*/
    		//(JSONObject)jsonarray[i]
        }
    }

然后在java方法中调用即可。第一个参数是地址，第二个是需要传输的参数，需要把传输的参数转化成字符串。然后会把结果返回

Map<String,String> p=new HashMap<>();
    
            p.put("pushType","ALIAS");
            p.put("alert",re);
            p.put("target",userId);
            p.put("msgCode","1005");
            p.put("orderNum","");
            p.put("activityId",id);
            String s="";
            for (Map.Entry<String, String> entry : p.entrySet()) {
                s+="&"+entry.getKey()+"="+entry.getValue();
            }
            s=s.substring(1);
            String sr= HttpRequest.sendPost("http://112.64.35.222:9002/itcast/jpush/push",s);