Java 获取网络重定向URL(302重定向)
方法1：
1 import java.net.HttpURLConnection; 2 import java.net.URL; 3 4 import org.junit.Assert; 5 import org.junit.Test; 6 7 public class GetRedirectUrlTest { 8 @Test 9 public void test_getRedirectUrl() throws Exception { 10 String url="http://www.baidu.com/link?url=ByBJLpHsj5nXx6DESXbmMjIrU5W4Eh0yg5wCQpe3kCQMlJK_RJBmdEYGm0DDTCoTDGaz7rH80gxjvtvoqJuYxK"; 11 String expectUrl="http://www.zhihu.com/question/20583607/answer/16597802"; 12 String redictURL = getRedirectUrl(url); 13 Assert.assertEquals(expectUrl, redictURL); 14 } 15 16 /** 17 * 获取重定向地址 18 * @param path 19 * @return 20 * @throws Exception 21 */ 22 private String getRedirectUrl(String path) throws Exception { 23 HttpURLConnection conn = (HttpURLConnection) new URL(path) 24 .openConnection(); 25 conn.setInstanceFollowRedirects(false); 26 conn.setConnectTimeout(5000); 27 return conn.getHeaderField("Location"); 28 } 29 }
方法2：
1 /** 2 * 处理跳转链接，获取重定向地址 3 * @param url 源地址 4 * @return 目标网页的绝对地址 5 */ 6 public String getAbsUrl(String url){ 7 CloseableHttpClient httpclient = HttpClients.createDefault(); 8 HttpClientContext context = HttpClientContext.create(); 9 HttpGet httpget = new HttpGet(url); 10 CloseableHttpResponse response = null; 11 String absUrl = null; 12 try { 13 response = httpclient.execute(httpget, context); 14 HttpHost target = context.getTargetHost(); 15 List<URI> redirectLocations = context.getRedirectLocations(); 16 URI location = URIUtils.resolve(httpget.getURI(), target, redirectLocations); 17 System.out.println("Final HTTP location: " + location.toASCIIString()); 18 absUrl = location.toASCIIString(); 19 }catch(IOException e){ 20 e.printStackTrace(); 21 }catch (URISyntaxException e) { 22 e.printStackTrace(); 23 }finally { 24 try { 25 httpclient.close(); 26 response.close(); 27 } catch (IOException e) { 28 e.printStackTrace(); 29 } 30 } 31 return absUrl; 32 }
