输入URL更改时如何获取新URL？

Question

考虑此网址http://dx.doi.org/10.1006/jpdc.1997.1383。当我将其放入浏览器地址栏并按回车键时，该URL将变为http://www.sciencedirect.com/science/article/pii/S0743731597913836。使用Java，我如何获得第二个URL地址？

Answer 1

致电getUrl()

后，只需致电URLConnection个实例getInputStream()

Answer 2

URLConnection con = new URL( url ).openConnection();
System.out.println( "orignal url: " + con.getURL() );
con.connect();
System.out.println( "connected url: " + con.getURL() );
InputStream is = con.getInputStream();
System.out.println( "redirected url: " + con.getURL() );
is.close();