封装httpclient工具类

 <!-- HttpClient  -->
<dependency>
   <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.3.1</version>
</dependency>

import org.apache.http.client.config.RequestConfig;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * 封装远程调用的一些参数值
 */
@Configuration
public class HttpClient {
   
    @Value("${http.maxTotal}")
    private Integer maxTotal;

    @Value("${http.defaultMaxPerRoute}")
    private Integer defaultMaxPerRoute;

    @Value("${http.connectTimeout}")
    private Integer connectTimeout;

    @Value("${http.connectionRequestTimeout}")
    private Integer connectionRequestTimeout;

    @Value("${http.socketTimeout}")
    private Integer socketTimeout;

    @Value("${http.staleConnectionCheckEnabled}")
    private boolean staleConnectionCheckEnabled;

    /**
     * 首先实例化一个连接池管理器，设置最大连接数、并发连接数
     *
     * @return
     */
    @Bean(name = "httpClientConnectionManager")
    public PoolingHttpClientConnectionManager getHttpClientConnectionManager() {
   
        PoolingHttpClientConnectionManager httpClientConnectionManager = new PoolingHttpClientConnectionManager();
        //最大连接数
        httpClientConnectionManager.setMaxTotal(maxTotal);
        //并发数
        httpClientConnectionManager.setDefaultMaxPerRoute(defaultMaxPerRoute);
        return httpClientConnectionManager;
    }

    /**
     * 实例化连接池，设置连接池管理器。
     * 这里需要以参数形式注入上面实例化的连接池管理器
     *
     * @param httpClientConnectionManager
     * @return
     */
    @Bean(name = "httpClientBuilder")
    public HttpClientBuilder getHttpClientBuilder(@Qualifier("httpClientConnectionManager") PoolingHttpClientConnectionManager httpClientConnectionManager) {
   

        //HttpClientBuilder中的构造方法被protected修饰，所以这里不能直接使用new来实例化一个HttpClientBuilder，可以使用HttpClientBuilder提供的静态方法create()来获取HttpClientBuilder对象
        HttpClientBuilder httpClientBuilder = HttpClientBuilder.create();

        httpClientBuilder.setConnectionManager(httpClientConnectionManager);

        return httpClientBuilder;
    }

    /**
     * 注入连接池，用于获取httpClient
     *
     * @param httpClientBuilder
     * @return
     */
    @Bean
    public CloseableHttpClient getCloseableHttpClient(@Qualifier("httpClientBuilder") HttpClientBuilder httpClientBuilder) {
   
        return httpClientBuilder.build();
    }

    /**
     * Builder是RequestConfig的一个内部类
     * 通过RequestConfig的custom方法来获取到一个Builder对象
     * 设置builder的连接信息
     * 这里还可以设置proxy，cookieSpec等属性。有需要的话可以在此设置
     *
     * @return
     */
    @Bean(name = "builder")
    public RequestConfig.Builder getBuilder() {
   
        RequestConfig.Builder builder = RequestConfig.custom();
        return builder.setConnectTimeout(connectTimeout)
                .setConnectionRequestTimeout(connectionRequestTimeout)
                .setSocketTimeout(socketTimeout)
                .setStaleConnectionCheckEnabled(staleConnectionCheckEnabled);
    }

    /**
     * 使用builder构建一个RequestConfig对象
     *
     * @param builder
     * @return
     */
    @Bean
    public RequestConfig getRequestConfig(@Qualifier("builder") RequestConfig.Builder builder) {
   
        return builder.build();
    }

/**
 * 封装响应结果
 */
public class HttpResult {
   
    // 响应的状态码
    private int code;

    // 响应的响应体
    private String body;

    public HttpResult(int code, String body) {
   
        this.code = code;
        this.body = body;
    }
    public HttpResult() {
   

    }
    public int getCode() {
   
        return code;
    }

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

    public String getBody() {
   
        return body;
    }

    public void setBody(String body) {
   
        this.body = body;
    }
}

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.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * @description: 远程调用封装
 * @author: sgw
 * @time: 2022/5/16 15:56
 */
@Service
public class HttpAPIService {
   
    @Autowired
    private CloseableHttpClient httpClient;

    @Autowired
    private RequestConfig config;
    /**
     * 不带参数的get请求，如果状态码为200，则返回body，如果不为200，则返回null
     *
     * @param url
     * @return
     * @throws Exception
     */
    public String doGet(String url) throws Exception {
   
        // 声明 http get 请求
        HttpGet httpGet = new HttpGet(url);

        // 装载配置信息
        httpGet.setConfig(config);

        // 发起请求
        CloseableHttpResponse response = this.httpClient.execute(httpGet);

        // 判断状态码是否为200
        if (response.getStatusLine().getStatusCode() == 200) {
   
            // 返回响应体的内容
            return EntityUtils.toString(response.getEntity(), "UTF-8");
        }
        return null;
    }

    /**
     * 带参数的get请求，如果状态码为200，则返回body，如果不为200，则返回null
     *
     * @param url
     * @return
     * @throws Exception
     */
    public String doGet(String url, Map<String, Object> map) throws Exception {
   
        URIBuilder uriBuilder = new URIBuilder(url);

        if (map != null) {
   
            // 遍历map,拼接请求参数
            for (Map.Entry<String, Object> entry : map.entrySet()) {
   
                uriBuilder.setParameter(entry.getKey(), entry.getValue().toString());
            }
        }

        // 调用不带参数的get请求
        return this.doGet(uriBuilder.build().toString());

    }

    /**
     * 带参数的post请求
     *
     * @param url
     * @param map
     * @return
     * @throws Exception
     */
    public HttpResult doPost(String url, Map<String, Object> map) throws Exception {
   
        // 声明httpPost请求
        HttpPost httpPost = new HttpPost(url);
        // 加入配置信息
        httpPost.setConfig(config);

        // 判断map是否为空，不为空则进行遍历，封装from表单对象
        if (map != null) {
   
            List<NameValuePair> list = new ArrayList<NameValuePair>();
            for (Map.Entry<String, Object> entry : map.entrySet()) {
   
                list.add(new BasicNameValuePair(entry.getKey(), entry.getValue().toString()));
            }
            // 构造from表单对象
            UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(list, "UTF-8");

            // 把表单放到post里
            httpPost.setEntity(urlEncodedFormEntity);
        }

        // 发起请求
        CloseableHttpResponse response = this.httpClient.execute(httpPost);
        return new HttpResult(response.getStatusLine().getStatusCode(), EntityUtils.toString(
                response.getEntity(), "UTF-8"));
    }

    /**
     * 不带参数post请求
     *
     * @param url
     * @return
     * @throws Exception
     */
    public HttpResult doPost(String url) throws Exception {
   
        return this.doPost(url, null);
    }
}

@RestController
@RequestMapping(value = "/addressBook")
class AddressBookController {
   

    @Resource
    private HttpAPIService httpAPIService;
    //http://127.0.0.1:80/SystemManagement/addressBook/getAddressBook?uuid=0282d2fe8859431baf94dc56140df9ee
    @GetMapping("/getAddressBook")
    public  void getAddressBook (@RequestParam String uuid) throws Exception{
   

        //测试调用远程接口
        String str = httpAPIService.doGet("http://www.baidu.com");
        System.out.println(str);
    }
}