Target host is not specified 异常

程序语言 Java
1

org.apache.http.ProtocolException: Target host is not specified 异常

程序代码：

[code]import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.HttpResponse;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.Header;
import org.apache.http.HttpHeaders;

public class UnshorteningUrl {

public static void main(String[] args) throws Exception
{           
    HttpGet request=null;
    HttpClient client = HttpClientBuilder.create().build();         

    try {
        request = new HttpGet("trib.me/1lBFzSi");
        HttpResponse httpResponse=client.execute(request);

        Header[] headers = httpResponse.getHeaders(HttpHeaders.LOCATION);
       // Preconditions.checkState(headers.length == 1);
        String newUrl = headers[0].getValue();          
        System.out.println("new url" + newUrl);         
    } catch (IllegalArgumentException e) {
        // TODO: handle exception
    }finally {
        if (request != null) {
            request.releaseConnection();
        }           
    }
}}[/code]

错误栈：

Exception in thread "main" org.apache.http.client.ClientProtocolException at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:186) at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82) at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:106) at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:57) at UnshorteningUrl.main(UnshorteningUrl.java:26) Caused by: org.apache.http.ProtocolException: Target host is not specified at org.apache.http.impl.conn.DefaultRoutePlanner.determineRoute(DefaultRoutePlanner.java:69) at org.apache.http.impl.client.InternalHttpClient.determineRoute(InternalHttpClient.java:124) at org.apache.http.impl.client.InternalHttpClient.doExecute(InternalHttpClient.java:183) ... 4 more