HttpClient使用小结

1、引入maven依赖(本文的工具类只是适配与当前引入的依赖，如果其他版本依赖，需自行调试)

        
            org.apache.httpcomponents
            httpclient
            4.5.8
        
     

2、创建封装httpClient响应结果实体

package com.schedule.common.model;

import java.io.Serializable;

/**
 * 封装httpClient响应结果
 */
public class HttpClientResult implements Serializable  {

    /**
     * 响应状态码
     */
    private int code;

    /**
     * 响应数据
     */
    private String content;

    /**
     * 构造方法
     */
    public HttpClientResult() {
    }

    /**
     * 构造方法
     * @param code
     */
    public HttpClientResult(int code) {
        this.code = code;
    }

    /**
     * 构造方法
     * @param code
     * @param content
     */
    public HttpClientResult(int code, String content) {
        this.code = code;
        this.content = content;
    }

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    public String getContent() {
        return content;
    }

    public void setContent(String content) {
        this.content = content;
    }
}

3、HttpClient工具类

package com.schedule.common.util;

import com.wd.schedule.common.model.HttpClientResult;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.*;
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.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.*;

/**
 * HttpClient工具类
 */
public class HttpClientUtils {

    // 编码格式。发送编码格式统一用UTF-8
    private static final String ENCODING = "UTF-8";

    // 设置连接超时时间，单位毫秒。
    private static final int CONNECT_TIMEOUT = 6000;

    // 请求获取数据的超时时间(即响应时间)，单位毫秒。
    private static final int SOCKET_TIMEOUT = 6000;

    /**
     * 发送get请求；不带请求头和请求参数
     * @param url 请求地址
     * @return
     * @throws Exception
     */
    public static HttpClientResult doGet(String url) throws Exception {
        return doGet(url, null, null);
    }

    /**
     * 发送get请求；带请求参数
     * @param url 请求地址
     * @param params 请求参数集合
     * @return
     * @throws Exception
     */
    public static HttpClientResult doGet(String url, Map params) throws Exception {
        return doGet(url, null, params);
    }

    /**
     * 发送get请求；带请求头和请求参数
     * @param url 请求地址
     * @param headers 请求头集合
     * @param params 请求参数集合
     * @return
     * @throws Exception
     */
    public static HttpClientResult doGet(String url, Map headers, Map params) throws Exception {
        // 创建httpClient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();

        // 创建访问的地址
        URIBuilder uriBuilder = new URIBuilder(url);
        if (params != null) {
            Set> entrySet = params.entrySet();
            for (Map.Entry entry : entrySet) {
                uriBuilder.setParameter(entry.getKey(), entry.getValue());
            }
        }

        // 创建http对象
        HttpGet httpGet = new HttpGet(uriBuilder.build());
        /**
         * setConnectTimeout：设置连接超时时间，单位毫秒。
         * setConnectionRequestTimeout：设置从connect Manager(连接池)获取Connection
         * 超时时间，单位毫秒。这个属性是新加的属性，因为目前版本是可以共享连接池的。
         * setSocketTimeout：请求获取数据的超时时间(即响应时间)，单位毫秒。 如果访问一个接口，多少时间内无法返回数据，就直接放弃此次调用。
         */
        RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
        httpGet.setConfig(requestConfig);

        // 设置请求头
        packageHeader(headers, httpGet);

        // 创建httpResponse对象
        CloseableHttpResponse httpResponse = null;

        try {
            // 执行请求并获得响应结果
            return getHttpClientResult(httpResponse, httpClient, httpGet);
        } finally {
            // 释放资源
            release(httpResponse, httpClient);
        }
    }

    /**
     * 发送post请求；不带请求头和请求参数
     * @param url 请求地址
     * @return
     * @throws Exception
     */
    public static HttpClientResult doPost(String url) throws Exception {
        return doPost(url, null, null);
    }

    /**
     * 发送post请求；带请求参数
     * @param url 请求地址
     * @param params 参数集合
     * @return
     * @throws Exception
     */
    public static HttpClientResult doPost(String url, Map params) throws Exception {
        return doPost(url, null, params);
    }

    /**
     * 发送post请求；带请求头和请求参数
     * @param url 请求地址
     * @param headers 请求头集合
     * @param params 请求参数集合
     * @return
     * @throws Exception
     */
    public static HttpClientResult doPost(String url, Map headers, Map params) throws Exception {
        // 创建httpClient对象
        CloseableHttpClient httpClient = HttpClients.createDefault();

        // 创建http对象
        HttpPost httpPost = new HttpPost(url);
        /**
         * setConnectTimeout：设置连接超时时间，单位毫秒。
         * setConnectionRequestTimeout：设置从connect Manager(连接池)获取Connection
         * 超时时间，单位毫秒。这个属性是新加的属性，因为目前版本是可以共享连接池的。
         * setSocketTimeout：请求获取数据的超时时间(即响应时间)，单位毫秒。 如果访问一个接口，多少时间内无法返回数据，就直接放弃此次调用。
         */
        RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
        httpPost.setConfig(requestConfig);

        // 设置请求头
        packageHeader(headers, httpPost);
        // 封装请求参数
        packageParam(params, httpPost);

        // 创建httpResponse对象
        CloseableHttpResponse httpResponse = null;

        try {
            // 执行请求并获得响应结果
            return getHttpClientResult(httpResponse, httpClient, httpPost);
        } finally {
            // 释放资源
            release(httpResponse, httpClient);
        }
    }

    /**
     * 发送put请求；不带请求参数
     *
     * @param url 请求地址
     * @return
     * @throws Exception
     */
    public static HttpClientResult doPut(String url) throws Exception {
        return doPut(url);
    }

    /**
     * 发送put请求；带请求参数
     * @param url 请求地址
     * @param params 参数集合
     * @return
     * @throws Exception
     */
    public static HttpClientResult doPut(String url, Map params) throws Exception {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPut httpPut = new HttpPut(url);
        RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
        httpPut.setConfig(requestConfig);

        packageParam(params, httpPut);

        CloseableHttpResponse httpResponse = null;

        try {
            return getHttpClientResult(httpResponse, httpClient, httpPut);
        } finally {
            release(httpResponse, httpClient);
        }
    }

    /**
     * 发送delete请求；不带请求参数
     * @param url 请求地址
     * @return
     * @throws Exception
     */
    public static HttpClientResult doDelete(String url) throws Exception {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpDelete httpDelete = new HttpDelete(url);
        RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(CONNECT_TIMEOUT).setSocketTimeout(SOCKET_TIMEOUT).build();
        httpDelete.setConfig(requestConfig);

        CloseableHttpResponse httpResponse = null;
        try {
            return getHttpClientResult(httpResponse, httpClient, httpDelete);
        } finally {
            release(httpResponse, httpClient);
        }
    }

    /**
     * 发送delete请求；带请求参数
     * @param url 请求地址
     * @param params 参数集合
     * @return
     * @throws Exception
     */
    public static HttpClientResult doDelete(String url, Map params) throws Exception {
        if (params == null) {
            params = new HashMap();
        }

        params.put("_method", "delete");
        return doPost(url, params);
    }

    /**
     * Description: 封装请求头
     * @param params
     * @param httpMethod
     */
    public static void packageHeader(Map params, HttpRequestBase httpMethod) {
        // 封装请求头
        if (params != null) {
            Set> entrySet = params.entrySet();
            for (Map.Entry entry : entrySet) {
                // 设置到请求头到HttpRequestBase对象中
                httpMethod.setHeader(entry.getKey(), entry.getValue());
            }
        }
    }

    /**
     * Description: 封装请求参数
     * @param params
     * @param httpMethod
     * @throws UnsupportedEncodingException
     */
    public static void packageParam(Map params, HttpEntityEnclosingRequestBase httpMethod)
            throws UnsupportedEncodingException {
        // 封装请求参数
        if (params != null) {
            List nvps = new ArrayList();
            Set> entrySet = params.entrySet();
            for (Map.Entry entry : entrySet) {
                nvps.add(new BasicNameValuePair(entry.getKey(), entry.getValue()));
            }

            // 设置到请求的http对象中
            httpMethod.setEntity(new UrlEncodedFormEntity(nvps, ENCODING));
        }
    }

    /**
     * Description: 获得响应结果
     * @param httpResponse
     * @param httpClient
     * @param httpMethod
     * @return
     * @throws Exception
     */
    public static HttpClientResult getHttpClientResult(CloseableHttpResponse httpResponse,
                                                       CloseableHttpClient httpClient, HttpRequestBase httpMethod) throws Exception {
        // 执行请求
        httpResponse = httpClient.execute(httpMethod);

        // 获取返回结果
        if (httpResponse != null && httpResponse.getStatusLine() != null) {
            String content = "";
            if (httpResponse.getEntity() != null) {
                content = EntityUtils.toString(httpResponse.getEntity(), ENCODING);
            }
            return new HttpClientResult(httpResponse.getStatusLine().getStatusCode(), content);
        }
        return new HttpClientResult(HttpStatus.SC_INTERNAL_SERVER_ERROR);
    }

    /**
     * Description: 释放资源
     * @param httpResponse
     * @param httpClient
     * @throws IOException
     */
    public static void release(CloseableHttpResponse httpResponse, CloseableHttpClient httpClient) throws IOException {
        // 释放资源
        if (httpResponse != null) {
            httpResponse.close();
        }
        if (httpClient != null) {
            httpClient.close();
        }
    }
}

4、根据需求调用相应方法即可。