HttpClient学习

1、好的文章：

http://blog.csdn.net/wangpeng047/article/details/19624529

http://www.cnblogs.com/loveyakamoz/archive/2011/07/21/2113252.html

http://www.cnblogs.com/loveyakamoz/archive/2011/07/21/2112804.html

2.使用commons-httpclient封装的：需要导入commons-client.jar  commons-logging.jar   commons-codec.jar

（1）

import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.UnsupportedEncodingException;import org.apache.commons.httpclient.DefaultHttpMethodRetryHandler;import org.apache.commons.httpclient.HttpClient;import org.apache.commons.httpclient.HttpException;import org.apache.commons.httpclient.HttpMethod;import org.apache.commons.httpclient.HttpStatus;import org.apache.commons.httpclient.MultiThreadedHttpConnectionManager;import org.apache.commons.httpclient.methods.GetMethod;import org.apache.commons.httpclient.methods.PostMethod;import org.apache.commons.httpclient.methods.StringRequestEntity;import org.apache.commons.httpclient.params.HttpMethodParams;public class HttpUtil {    private static MultiThreadedHttpConnectionManager manager              = new MultiThreadedHttpConnectionManager();    private static int                                maxConnectionPerHost = 15;    private static int                                maxTotalConnections  = 40;    private static final int                          CONN_OUT_TIME             = 10 * 1000;    private static final int                          SO_OUT_TIME             = 240 * 1000;    // 初始化ConnectionManger的方法    public static void setPara(int timeout) {        manager.getParams().setConnectionTimeout(timeout);        manager.getParams().setSoTimeout(timeout);        manager.getParams().setDefaultMaxConnectionsPerHost(maxConnectionPerHost);        manager.getParams().setMaxTotalConnections(maxTotalConnections);    }    /**     * get请求,默认超时5s     *      * @param restUrl     * @param timeoutMillions     * @return     */    public static String getResponseByHttp(String restUrl) {        String responseStr = null;        HttpClient client = new HttpClient();        HttpMethod method = new GetMethod(restUrl);        client.getHttpConnectionManager().getParams().setConnectionTimeout(CONN_OUT_TIME);        client.getHttpConnectionManager().getParams().setSoTimeout(SO_OUT_TIME);        method.setRequestHeader("rest-who", "aries");        method.setRequestHeader("rest-code", "ccc558986e26577ce68b579995bfa01a");        try {            client.executeMethod(method);            method.getParams().setContentCharset("UTF-8");            if (method.getStatusCode() == HttpStatus.SC_OK) {                responseStr = method.getResponseBodyAsString();            }        } catch (Exception e) {//            log.error("request out of time, CONN_OUT_TIME="+CONN_OUT_TIME+", SO_OUT_TIME="+SO_OUT_TIME+", URL="+restUrl,e);        }        method.releaseConnection();        return responseStr;    }    /**     * get请求     *      * @param url     * @param encode     * @param timeOut     * @return     */    public static ResultDto<Integer, String> getGetResponseByHttp(String url, String encode, int timeout)                                                                                                        throws HttpException,                                                                                                        IOException {        HttpUtil.setPara(timeout);        HttpClient client = new HttpClient(manager);        GetMethod get = new GetMethod(url);        get.setFollowRedirects(true);        get.setRequestHeader("refer", "aries");        // 设置重试次数        get.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler(1, false));        int responseCode = HttpStatus.SC_NOT_FOUND;        StringBuffer resultBuffer = new StringBuffer();        String resultStr = null;        try {            responseCode = client.executeMethod(get);            BufferedReader in = new BufferedReader(new InputStreamReader(get.getResponseBodyAsStream(),                                                                         get.getResponseCharSet()));            String inputLine = null;            while ((inputLine = in.readLine()) != null) {                resultBuffer.append(inputLine);            }            in.close();            resultStr = HttpUtil.ConverterStringCode(resultBuffer.toString(), get.getResponseCharSet(), encode);        } finally {            get.releaseConnection();        }        if (responseCode > HttpStatus.SC_OK) {//            logger.error("url: " + url + " get error! return code is: " + responseCode);        }        return new ResultDto<Integer, String>(responseCode, resultStr);    }    public static ResultDto<Integer, String> getPostResponseWithHttpClient(String url, String encode,                                                                          String requestData, int timeout,String type)                                                                                                                   throws HttpException,                                                                                                                   IOException {        HttpClient client = new HttpClient(manager);        HttpUtil.setPara(timeout);        // 设置参数        PostMethod mtd = new PostMethod(url);        if(type.contains("XML")){            mtd.setRequestEntity(new StringRequestEntity(requestData,"text/xml","utf-8"));          }else if (type.contains("JSON")){            mtd.setRequestEntity(new StringRequestEntity(requestData,"text/json","utf-8"));        }else{            mtd.setRequestEntity(new StringRequestEntity(requestData,null,"utf-8"));        }        int responseCode = HttpStatus.SC_NOT_FOUND;        String resultStr = null;        try {            responseCode = client.executeMethod(mtd);            BufferedReader in = new BufferedReader(new InputStreamReader(mtd.getResponseBodyAsStream(),                                                                         mtd.getResponseCharSet()));            String inputLine = null;            StringBuffer resultBuffer = new StringBuffer();            while ((inputLine = in.readLine()) != null) {                resultBuffer.append(inputLine);            }            in.close();            resultStr = resultBuffer.toString();            resultStr = HttpUtil.ConverterStringCode(resultBuffer.toString(), mtd.getResponseCharSet(), encode);        } finally {            mtd.releaseConnection();        }        if (responseCode > HttpStatus.SC_OK) {//            logger.error("url: " + url + " get error! return code is: " + responseCode);        }        return new ResultDto<Integer, String>(responseCode, resultStr);    }    private static String ConverterStringCode(String source, String srcEncode, String destEncode) {        if (source != null) {            try {                return new String(source.getBytes(srcEncode), destEncode);            } catch (UnsupportedEncodingException e) {                return "";            }        } else {            return "";        }    }}

（2）dto类

public class ResultDto<A,B> {private A first;private B second;public ResultDto(A first,B second) {this.first = first;this.second = second;}public A getFirst() {return first;}public void setFirst(A first) {this.first = first;}public B getSecond() {return second;}public void setSecond(B second) {this.second = second;}}