前言

最近有个想法想整理一个内容比较完整springboot项目初始化Demo。

SpringBoot使用RestTemplate由服务端向外发起网络请求

一、将RestTemplate配置初始化为一个Bean

修改RestTemplate默认的客户端，例如将其改成HttpClient客户端

package com.murg.bootdemo.config;

import com.murg.bootdemo.interceptor.HeaderRequestInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

import java.util.ArrayList;
import java.util.List;

@Configuration
public class RestClientConfig {

    @Bean
    public ClientHttpRequestFactory clientHttpRequestFactory() {
        SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
        factory.setConnectTimeout(180000);//设置连接超时时间
        factory.setReadTimeout(180000);//读取超时时间
        return factory;
    }

    /**
     * DependsOn注解用于确保所使用的bean已被初始化
     * @param clientHttpRequestFactory 设置
     * @return org.springframework.web.client.RestTemplate
     */
    @Bean
    public RestTemplate restTemplate(ClientHttpRequestFactory clientHttpRequestFactory) {
        List<ClientHttpRequestInterceptor> interceptors = new ArrayList<>();
        interceptors.add(new HeaderRequestInterceptor());
        RestTemplate restTemplate =  new RestTemplate(clientHttpRequestFactory);
        restTemplate.setInterceptors(interceptors);
        return restTemplate;
//        //配置HTTP超时时间
//        HttpComponentsClientHttpRequestFactory httpRequestFactory = new HttpComponentsClientHttpRequestFactory(
//                HttpClientBuilder.create()
//                        .setMaxConnTotal(100)//最大连接池
//                        .setMaxConnPerRoute(50)//每个池最大连接数
//                        .build());
//        httpRequestFactory.setConnectTimeout(120000);
//        httpRequestFactory.setReadTimeout(180000);
//        return new RestTemplate(httpRequestFactory);
    }

}

二、使用RestTemplate

TestRestController 注入 RestTemplate

新增测试/rest/authenticate 接口  通过RestTemplate方式获取token

 @RequestMapping(value = "/rest/authenticate", method = RequestMethod.GET)
    public WebResult restAuthenticate(){
        String url = "http://127.0.0.1:8081/api/authenticate";
        // 由于获取student接口咱们设置了basicauth，所以需要在请求时配置
        HttpHeaders headers = new HttpHeaders();
        // 需要传递FORMDATA的请求参数
        headers.setContentType(MediaType.APPLICATION_JSON);
        Map params =new HashMap();
        params.put("username", "admin");
        params.put("password", "123456");
        params.put("clientid", "clientid");
        HttpEntity httpEntity = new HttpEntity(params, headers);
        ResponseEntity<WebResult> response = null;
        try {
            // 通过POST方式调用接口，如果需要PUT，DELETE方式调用
            // 只需要修改为HttpMethod.PUT，HttpMethod.DELETE即可，其他传递参数已经代码一致
            response = restTemplate.exchange(url, HttpMethod.POST, httpEntity, WebResult.class);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        return response.getBody();
    }

三、自定义HeaderRequestInterceptor拦截器

自定义HeaderRequestInterceptor继承ClientHttpRequestInterceptor的拦截器。处理Header信息，此处增加接口访问时间打印

package com.murg.bootdemo.interceptor;

import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpRequestInterceptor;
import org.springframework.http.client.ClientHttpResponse;

import java.io.IOException;

/**
 * @version 1.0
 * @Description: 给不同的请求地址 添加不同的header
 */
@Slf4j
public class HeaderRequestInterceptor implements ClientHttpRequestInterceptor {

    @Override
    public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution) throws IOException {
        long startTime = System.currentTimeMillis();
        ClientHttpResponse response= null;
        try {
            response = execution.execute(request, body);
        } catch (IOException e) {
           throw e;
        }finally {
            long endTime = System.currentTimeMillis();
            long duration = endTime - startTime;
            log.info("Request URL: " + request.getURI() + " 耗时 " + duration + "ms");
        }
        return response;
    }
}

四、postman测试

控制台打印耗时

 [Request URL: http://127.0.0.1:8081/api/authenticate 耗时 10ms]