java发起http请求调用post

java发起http请求调用post

Post请求：

public static String sendPost(String url, String param) {
          
   
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
          
   
        	//这里我被调用的接口是问号键值传参，我就直接将参数放到连接中了,下边的param就可以不用设置了
        	// url = "https://域名地址/sendPost?Id="+regId;
            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("Content-Type","application/json;charset=UTF-8");
			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(), "UTF-8");
            // 发送请求参数，如果被调用的接口参数是传json串，将param转换为json串即可
            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;
    }