分享自己配置的URLConnection和HttpURLConnection请求数据工具类
>>该工具类传入string类型url返回string类型获取结果
import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.net.HttpURLConnection; import java.net.URL; import java.net.URLDecoder; /** * Created by ZJQ on 2016/5/20. */ //获取网络返回数据 public class GetNetJson { public String getJson(String urlstring) { String result = ""; try { URL url = new URL(urlstring); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setConnectTimeout(4000); connection.setRequestMethod("GET"); //设置通讯的头部信息,设置访问方式 connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"); connection.connect(); if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) { //获取流 InputStream inputStream = connection.getInputStream(); BufferedReader br = new BufferedReader(new InputStreamReader(inputStream, "utf-8")); StringBuffer resultBuffer = new StringBuffer(); String tempLine = null; while ((tempLine = br.readLine()) != null) { resultBuffer.append(tempLine); } result = resultBuffer.toString(); br.close(); inputStream.close(); return result; } } catch (Exception e) { e.printStackTrace(); } return result; } }
>>期初由于该没有设置该属性导致app无法连接到网络
connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)");
调用方式:
String result = getNetJson.getJson("www.baidu.com");
以下是最近(18年8月)才写的urlconnection类,其实httpurlconectin是URLConnection的子类,看过源码的都知道。所以他俩大同小异
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 RequestPayTool { /** * 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 */ public static String sendGet(String url, String param) { String result = ""; BufferedReader in = null; try { String urlName = url + "?" + param; URL realUrl = new URL(urlName); // 打开和URL之间的连接 URLConnection conn = realUrl.openConnection(); // 设置通用的请求属性 conn.setConnectTimeout(60000); // conn.setRequestProperty("accept", "*/*"); // conn.setRequestProperty("connection", "Keep-Alive"); // conn.setRequestProperty("user-agent", // "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)"); // 建立实际的连接 conn.connect(); // 获取所有响应头字段 Map<String, List<String>> map = conn.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(conn.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 (IOException ex) { ex.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 URL所代表远程资源的响应 */ public static String sendPost(String url, String param,int timeOut) { 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(); conn.setConnectTimeout(timeOut); // 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; } }