通过ResponseHandler来处理Http响应

处理对响应对象处理过程的封装

package com.struts2.demo;

import com.struts2.demo.utils.AvailableSettings;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.http.Consts;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.StatusLine;
import org.apache.http.client.ResponseHandler;
import org.apache.http.client.fluent.Request;
import org.apache.http.entity.ContentType;
import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.io.SAXReader;

import java.io.IOException;

/**
 * Handler that encapsulates the process of generating a response object from a HttpResponse.
 * Created by Frank on 2014/6/9.
 */
public class FluentResponseHandling {
    private static final Log logger = LogFactory.getLog(AvailableSettings.LOGNAME_TEST);

    public static void main(String[] args) {
        try {
            Document document = Request.Get("http://www.baidu.com").execute().handleResponse(new ResponseHandler() {
                @Override
                public Document handleResponse(HttpResponse response) {
                    return getXmlDoc(response);
                }
            });
            System.out.println(document.asXML());
        } catch (IOException e) {
            logger.error("IOException:" + e.getMessage());
        }
    }

    private static Document getXmlDoc(HttpResponse response) {
        StatusLine statusLine = response.getStatusLine();
        HttpEntity httpEntity = response.getEntity();
        if (statusLine.getStatusCode() >= 300) {
            logger.error("HttpResponseException,statusCode:" + statusLine.getStatusCode() + " reasonPhrase:" + statusLine.getReasonPhrase());
            return null;
        }
        if (null == httpEntity) {
            logger.error("ClientProtocolException:Response contains no content");
            return null;
        }
        ContentType contentType = ContentType.getOrDefault(httpEntity);
        if (!contentType.equals(ContentType.APPLICATION_XML)) {
            logger.error("Unexpected content type:" + contentType);
            return null;
        }

        SAXReader saxReader = new SAXReader();
        saxReader.setEncoding(Consts.UTF_8.name());
        saxReader.setValidation(false);
        try {
            return saxReader.read(httpEntity.getContent());
        } catch (DocumentException | IOException e) {
            logger.error("axReader.read exception:" + e.getMessage());
            return null;
        }
    }
}