通过httpClient获取重定向后的页面链接地址（应用与百度链接跳转获取原网页的链接地址）

importorg.apache.http.HttpEntity;

importorg.apache.http.HttpHost;

importorg.apache.http.HttpResponse;

importorg.apache.http.client.HttpClient;

importorg.apache.http.client.methods.HttpGet;

importorg.apache.http.client.methods.HttpUriRequest;

importorg.apache.http.entity.ContentType;

importorg.apache.http.impl.client.DefaultHttpClient;

importorg.apache.http.protocol.BasicHttpContext;

importorg.apache.http.protocol.ExecutionContext;

importorg.apache.http.protocol.HttpContext;

importorg.apache.http.util.EntityUtils;

 

publicclass HttpClientDemo {

 

    /**

     * 获取重定向之后的网址信息

     * @see HttpClient缺省会自动处理客户端重定向

     * @see 即访问网页A后,假设被重定向到了B网页,那么HttpClient将自动返回B网页的内容

     * @see 若想取得B网页的地址,就需要借助HttpContext对象,HttpContext实际上是客户端用来在多次请求响应的交互中,保持状态信息的

     * @see 我们自己也可以利用HttpContext来存放一些我们需要的信息,以便下次请求的时候能够取出这些信息来使用

     */

    publicstatic void getRedirectInfo(){

        HttpClient httpClient = newDefaultHttpClient();

        HttpContext httpContext = newBasicHttpContext();

        HttpGet httpGet = newHttpGet("http://127.0.0.1:8088/blog/main.jsp");

        try{

            //将HttpContext对象作为参数传给execute()方法,则HttpClient会把请求响应交互过程中的状态信息存储在HttpContext中

            HttpResponse response = httpClient.execute(httpGet, httpContext);

            //获取重定向之后的主机地址信息,即"http://127.0.0.1:8088"

            HttpHost targetHost = (HttpHost)httpContext.getAttribute(ExecutionContext.HTTP_TARGET_HOST);

            //获取实际的请求对象的URI,即重定向之后的"/blog/admin/login.jsp"

            HttpUriRequest realRequest = (HttpUriRequest)httpContext.getAttribute(ExecutionContext.HTTP_REQUEST);

            System.out.println("主机地址:"+ targetHost);

            System.out.println("URI信息:"+ realRequest.getURI());

            HttpEntity entity = response.getEntity();

            if(null!= entity){

                System.out.println("响应内容:"+ EntityUtils.toString(entity, ContentType.getOrDefault(entity).getCharset()));

                EntityUtils.consume(entity);

            }

        }catch(Exception e) {

            e.printStackTrace();

        }finally{

            httpClient.getConnectionManager().shutdown();

        }

    }

}