HttpClient4.x工具获取如何使用

HttpClient4.x工具可以让我们输入url,就可以请求某个页面(个人感觉挺实用的,特别是封装在代码中)

首先我们需要在maven工程中添加依赖

<dependency>

                <groupId>org.apache.httpcomponents</groupId>

                <artifactId>httpclient</artifactId>

                <version>4.5.3</version>

            </dependency>

            <dependency>

                <groupId>org.apache.httpcomponents</groupId>

                <artifactId>httpmime</artifactId>

                <version>4.5.2</version>

            </dependency>

 

            <dependency>

                <groupId>commons-codec</groupId>

                <artifactId>commons-codec</artifactId>

            </dependency>

            <dependency>

                <groupId>commons-logging</groupId>

                <artifactId>commons-logging</artifactId>

                <version>1.1.1</version>

            </dependency>

                    <dependency>

                    <groupId>org.apache.httpcomponents</groupId>

                    <artifactId>httpcore</artifactId>

            </dependency>

 

 

        <!-- gson工具，封装http的时候使用 -->

        <dependency>

            <groupId>com.google.code.gson</groupId>

            <artifactId>gson</artifactId>

            <version>2.8.0</version>

        </dependency>

 

接下来,我们来封装一下,有get/post请求

 /**
 * 封装http get post
 */
 public class HttpUtils {

 private static final Gson gson = new Gson();
 /**
 * get方法
 */
 public static Map<String,Object> doget(String url,int timeout){
 Map<String,Object> map = new HashMap<>();
 CloseableHttpClient httpClient = HttpClients.createDefault();
　　//配置可有可无,根据个人情景
 RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(timeout) //设置连接超时时间
 .setConnectionRequestTimeout(timeout) //设置请求超时时间
 .setSocketTimeout(timeout)
 .setRedirectsEnabled(true) //设置允许自动重定向
 .build();
 HttpGet httpGet = new HttpGet(url);
 httpGet.setConfig(requestConfig);

 try {
 HttpResponse httpResponse = httpClient.execute(httpGet);
 if(httpResponse.getStatusLine().getStatusCode() == 200){
 String jsonResult = EntityUtils.toString(httpResponse.getEntity());
 map = gson.fromJson(jsonResult, map.getClass()); //通过gson工具,将响应流转换成map集合
 }

 }catch(Exception e){
 e.printStackTrace();
 }finally{
 try{
 httpClient.close();
 }catch(Exception e) {
 e.printStackTrace();
 }
 }
 return map;
 }
 /**
 * 封装post,与get有异曲同工之妙
 */
 public static String dopost(String url,String data,int timeout){
 CloseableHttpClient httpClient = HttpClients.createDefault();
 RequestConfig requestConfig = RequestConfig.custom().setConnectionRequestTimeout(timeout) //设置连接超时
 .setConnectionRequestTimeout(timeout) //设置请求超时
 .setRedirectsEnabled(true) //设置允许自动重定向
 .build();

 HttpPost httpPost = new HttpPost(url);
 httpPost.setConfig(requestConfig);
 httpPost.addHeader("Content-Type","text/html; chartset=UTF-8"); //添加头信息
 if (data != null && data instanceof String) {//使用字符串传参
 StringEntity stringEntity = new StringEntity(data, "UTF-8");
 httpPost.setEntity(stringEntity);
 }
 try {
 CloseableHttpResponse httpResponse = httpClient.execute(httpPost);
 HttpEntity httpEntity = httpResponse.getEntity();
 if (httpResponse.getStatusLine().getStatusCode() == 200){
 String result = EntityUtils.toString(httpEntity);
 return result;
 }
 } catch (Exception e) {
 e.printStackTrace();
 }finally {
 try{
 httpClient.close();
 }catch (Exception e){
 e.printStackTrace();
 }
 }

 return null;

 }
 }

封装好HttpClient工具后,我们来调用一下

get请求

HttpUtils.doget(请求地址,请求时间(timeout));

post请求

HttpUtils.dopost(请求地址, 请求传的数据(传之前需要转换成string), 请求时间(timeout));