基于HttpClient4.5.1实现Http访问工具类

本工具类基于httpclient4.5.1实现

<dependency>
<groupId>org.apache.httpcomponents</groupId>
<artifactId>httpclient</artifactId>
<version>4.5.1</version>
</dependency>
 
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URISyntaxException;
import java.util.ArrayList;
import java.util.Map;

import org.apache.http.HttpEntity;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;

import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

/**
 * 
 * @author Nan 2015-11
 */
public class HttpClientUtil {
    private static PoolingHttpClientConnectionManager cm;
    private static String EMPTY_STR = "";
    private static String UTF_8 = "UTF-8";

    private static void init() {
        if (cm == null) {
            cm = new PoolingHttpClientConnectionManager();
            cm.setMaxTotal(50);// 整个连接池最大连接数
            cm.setDefaultMaxPerRoute(5);// 每路由最大连接数,默认值是2
        }
    }

    /**
     * 通过连接池获取HttpClient
     * 
     * @return
     */
    private static CloseableHttpClient getHttpClient() {
        init();
        return HttpClients.custom().setConnectionManager(cm).build();
    }

    /**
     * 
     * @param url
     * @return
     */
    public static String httpGetRequest(String url) {
        HttpGet httpGet = new HttpGet(url);
        return getResult(httpGet);
    }

    public static String httpGetRequest(String url, Map<String, Object> params) throws URISyntaxException {
        URIBuilder ub = new URIBuilder();
        ub.setPath(url);

        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        ub.setParameters(pairs);

        HttpGet httpGet = new HttpGet(ub.build());
        return getResult(httpGet);
    }

    public static String httpGetRequest(String url, Map<String, Object> headers, Map<String, Object> params)
            throws URISyntaxException {
        URIBuilder ub = new URIBuilder();
        ub.setPath(url);

        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        ub.setParameters(pairs);

        HttpGet httpGet = new HttpGet(ub.build());
        for (Map.Entry<String, Object> param : headers.entrySet()) {
            httpGet.addHeader(param.getKey(), String.valueOf(param.getValue()));
        }
        return getResult(httpGet);
    }

    public static String httpPostRequest(String url) {
        HttpPost httpPost = new HttpPost(url);
        return getResult(httpPost);
    }

    public static String httpPostRequest(String url, Map<String, Object> params) throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(url);
        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        httpPost.setEntity(new UrlEncodedFormEntity(pairs, UTF_8));
        return getResult(httpPost);
    }

    public static String httpPostRequest(String url, Map<String, Object> headers, Map<String, Object> params)
            throws UnsupportedEncodingException {
        HttpPost httpPost = new HttpPost(url);

        for (Map.Entry<String, Object> param : headers.entrySet()) {
            httpPost.addHeader(param.getKey(), String.valueOf(param.getValue()));
        }

        ArrayList<NameValuePair> pairs = covertParams2NVPS(params);
        httpPost.setEntity(new UrlEncodedFormEntity(pairs, UTF_8));

        return getResult(httpPost);
    }

    private static ArrayList<NameValuePair> covertParams2NVPS(Map<String, Object> params) {
        ArrayList<NameValuePair> pairs = new ArrayList<NameValuePair>();
        for (Map.Entry<String, Object> param : params.entrySet()) {
            pairs.add(new BasicNameValuePair(param.getKey(), String.valueOf(param.getValue())));
        }

        return pairs;
    }

    /**
     * 处理Http请求
     * 
     * @param request
     * @return
     */
    private static String getResult(HttpRequestBase request) {
        // CloseableHttpClient httpClient = HttpClients.createDefault();
        CloseableHttpClient httpClient = getHttpClient();
        try {
            CloseableHttpResponse response = httpClient.execute(request);
            // response.getStatusLine().getStatusCode();
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                // long len = entity.getContentLength();// -1 表示长度未知
                String result = EntityUtils.toString(entity);
                response.close();
                // httpClient.close();
                return result;
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {

        }

        return EMPTY_STR;
    }

}

 Json版本

import net.sf.json.JSONObject;
import org.apache.commons.httpclient.HttpStatus;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
 
import java.io.IOException;
import java.net.URLDecoder;
 
public class HttpRequestUtils {
    private static Logger logger = LoggerFactory.getLogger(HttpRequestUtils.class);    //日志记录
 
    /**
     * httpPost
     * @param url  路径
     * @param jsonParam 参数
     * @return
     */
    public static JSONObject httpPost(String url,JSONObject jsonParam){
        return httpPost(url, jsonParam, false);
    }
 
    /**
     * post请求
     * @param url         url地址
     * @param jsonParam     参数
     * @param noNeedResponse    不需要返回结果
     * @return
     */
    public static JSONObject httpPost(String url,JSONObject jsonParam, boolean noNeedResponse){
        //post请求返回结果
        DefaultHttpClient httpClient = new DefaultHttpClient();
        JSONObject jsonResult = null;
        HttpPost method = new HttpPost(url);
        try {
            if (null != jsonParam) {
                //解决中文乱码问题
                StringEntity entity = new StringEntity(jsonParam.toString(), "utf-8");
                entity.setContentEncoding("UTF-8");
                entity.setContentType("application/json");
                method.setEntity(entity);
            }
            HttpResponse result = httpClient.execute(method);
            url = URLDecoder.decode(url, "UTF-8");
            /**请求发送成功,并得到响应**/
            if (result.getStatusLine().getStatusCode() == 200) {
                String str = "";
                try {
                    /**读取服务器返回过来的json字符串数据**/
                    str = EntityUtils.toString(result.getEntity());
                    if (noNeedResponse) {
                        return null;
                    }
                    /**把json字符串转换成json对象**/
                    jsonResult = JSONObject.fromObject(str);
                } catch (Exception e) {
                    logger.error("post请求提交失败:" + url, e);
                }
            }
        } catch (IOException e) {
            logger.error("post请求提交失败:" + url, e);
        }
        return jsonResult;
    }
 
 
    /**
     * 发送get请求
     * @param url    路径
     * @return
     */
    public static JSONObject httpGet(String url){
        //get请求返回结果
        JSONObject jsonResult = null;
        try {
            DefaultHttpClient client = new DefaultHttpClient();
            //发送get请求
            HttpGet request = new HttpGet(url);
            HttpResponse response = client.execute(request);
 
            /**请求发送成功,并得到响应**/
            if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
                /**读取服务器返回过来的json字符串数据**/
                String strResult = EntityUtils.toString(response.getEntity());
                /**把json字符串转换成json对象**/
                jsonResult = JSONObject.fromObject(strResult);
                url = URLDecoder.decode(url, "UTF-8");
            } else {
                logger.error("get请求提交失败:" + url);
            }
        } catch (IOException e) {
            logger.error("get请求提交失败:" + url, e);
        }
        return jsonResult;
    }
}
原文地址:https://www.cnblogs.com/MarchThree/p/6839044.html