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Example of using Java to send http requests natively

黄舟
黄舟 Original
2017-09-25 10:59:35 2057browse


Java uses native example to send http request

package com.teamsun.pay.wxpay.util; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; 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)"); //setConnectTimeout:设置连接主机超时(单位:毫秒) connection.setConnectTimeout(2000);//2秒超时 //setReadTimeout:设置从主机读取数据超时(单位:毫秒) //connection.setReadTimeout(2000); // 建立实际的连接 connection.connect(); // 获取所有响应头字段 Map> 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", "*/*"); 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())); 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) { } }

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