RestTemplate技术-访问http请求-OkHttp

左手的ㄟ右手 2024-03-27 15:44 65阅读 0赞

## **一、认识RestTemplate** ##

RestTemplate 是 Spring 提供的用于访问 RESTful 服务的客户端， RestTemplate 提供了多种便捷访问远程 Http 服务 的方法, 能够大大提高客户端的编写效率。 RestTemplate 默认依赖 JDK 提供 http 连接的能力 （HttpURLConnection ），也可以通过替换为例如  Apache HttpComponents 、 Netty 或 OkHttp 等其它 HTTP  客户端，目前OkHttp 的性能最优越。 官网： https://square.github.io/okhttp/ ， github ：  https://github.com/square/okhttp

## 二、集成**RestTemplate** ##

### **1、添加依赖** ###

<!‐‐ okhttp3依赖 ‐‐>
    <dependency> 
        <groupId>com.squareup.okhttp3</groupId>
        <artifactId>okhttp</artifactId>
        <version>3.9.1</version>
    </dependency>

### 2、RestTemplate初始化 ###

package com.ruoyi.framework.config;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.http.MediaType;
    import org.springframework.http.client.ClientHttpRequestFactory;
    import org.springframework.http.client.OkHttp3ClientHttpRequestFactory;
    import org.springframework.http.client.SimpleClientHttpRequestFactory;
    import org.springframework.http.converter.HttpMessageConverter;
    import org.springframework.http.converter.StringHttpMessageConverter;
    import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
    import org.springframework.web.client.RestTemplate;
    
    import java.nio.charset.StandardCharsets;
    import java.util.Arrays;
    import java.util.List;
    
    @Configuration
    public class RestTemplateConfig {
    
        @Bean
        public RestTemplate restTemplate(){
            RestTemplate restTemplate = new RestTemplate(new OkHttp3ClientHttpRequestFactory());
            //得到消息转换器
            List<HttpMessageConverter<?>> messageConverters = restTemplate.getMessageConverters();
            //指定StringHttpMessageConverter消息转换器的字符集为utf-8中文编码
            messageConverters.set(1,new StringHttpMessageConverter(StandardCharsets.UTF_8));
            //设置支持的媒体类型 json/text
            MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter();
            mappingJackson2HttpMessageConverter.setSupportedMediaTypes(Arrays.asList(MediaType.APPLICATION_JSON, MediaType.APPLICATION_OCTET_STREAM, MediaType.TEXT_HTML));
            // 添加MappingJackson2HttpMessageConverter转换器
            restTemplate.getMessageConverters().add(mappingJackson2HttpMessageConverter);
            return  restTemplate;
        }
    
        @Bean
        public ClientHttpRequestFactory simpleClientHttpRequestFactory() {
            SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
            factory.setReadTimeout(600_000);//单位为ms
            factory.setConnectTimeout(60_000);//单位为ms
            return factory;
        }
    }

**注意：当RestTemplate默认使用String存储body内容时默认使用ISO\_8859\_1字符集。必须配置StringHttpMessageConverter 消息转换器，使用utf-8字符集，要不然中文乱码。**

## 三、测试 ##

### 一、使用RestTemplate获取百度的网页内容和短信测试 ###

package com.***.merchant;
    
    import com.alibaba.fastjson.JSON;
    import lombok.extern.slf4j.Slf4j;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.http.*;
    import org.springframework.test.context.junit4.SpringRunner;
    import org.springframework.web.client.RestTemplate;
    
    import java.util.HashMap;
    import java.util.Map;
    
    /**
     * @author xiyuan
     * @version 1.0
     **/
    @SpringBootTest
    @RunWith(SpringRunner.class)
    @Slf4j
    public class RestTemplateTest {
    
        @Autowired
        RestTemplate restTemplate;
    
        //测试使用restTemplate作为http的客户端向http服务端发起请求
        @Test
        public void gethtml(){
            String url = "http://www.baidu.com/";
            //向url发送http请求，得到响应结果
            ResponseEntity<String> forEntity = restTemplate.getForEntity(url, String.class);
            String body = forEntity.getBody();
            System.out.println(body);
    
        }
    
        //向验证码服务发送请求，获取验证码
        //http://localhost:56085/sailing/generate?effectiveTime=600&name=sms
        @Test
        public void getSmsCode(){
            String url = "http://localhost:56085/sailing/generate?effectiveTime=600&name=sms";
    
            //请求体
            Map<String,Object> body = new HashMap<>();
            body.put("mobile","133456");
            //请求头
            HttpHeaders httpHeaders =new HttpHeaders();
            //指定Content-Type: application/json
            httpHeaders.setContentType(MediaType.APPLICATION_JSON);
            //请求信息,传入body，header
            HttpEntity httpEntity = new HttpEntity(body,httpHeaders);
            //向url请求
            ResponseEntity<Map> exchange = restTemplate.exchange(url, HttpMethod.POST, httpEntity, Map.class);
    
            log.info("请求验证码服务，得到响应:{}", JSON.toJSONString(exchange));
            Map bodyMap = exchange.getBody();
            System.out.println(bodyMap);
            Map result = (Map) bodyMap.get("result");
            String key = (String) result.get("key");
            System.out.println(key);
        }
    }

### 二、获取企业微信 AccessToken ###

具体示例见：[企业微信授权获取access\_token][access_token]

@Component
    @Slf4j
    public class QiYeWeChatUtil {
    
        /**
         * 缓存企业微信accessToken
         */
        public static final String QY_WX_TOKEN_kEY = "qy_wx_token:";
    
        @Autowired
        private QyWxConfig qyWxConfig;
    
        @Resource
        private RestService restService;
    
        @Autowired
        private RedisCache redisCache;
    
    
        /**
         * 获取企业微信 AccessToken
         *
         * @return
         */
        public String getAccessToken() {
    
            if (!redisCache.hasKey(QY_WX_TOKEN_kEY)) {
                //请求头
                HttpHeaders header = new HttpHeaders();
                header.setContentType(MediaType.APPLICATION_JSON);
    
                //请求信息,传入header
                HttpEntity<Map<String, String>> formEntity = new HttpEntity<>(header);
                StringBuilder urlBuilder = new StringBuilder(企业微信tUrl());
                urlBuilder.append("?").append("corpid=").append(企业微信Corpid());
                urlBuilder.append("&").append("corpsecret=").append(企业微信tCorpsecret());
    
                try {
                    ResponseEntity<Map> entity = restService.getForEntity(urlBuilder.toString(), formEntity, Map.class);
    
                    log.info("请求企业微信，得到响应:{}", entity);
                    Map body = entity.getBody();
                    String accessToken = (String) body.get("access_token");
                    Integer expires_in = (Integer) body.get("expires_in");
                    redisCache.setCacheObject(QY_WX_TOKEN_kEY,accessToken, 7200, TimeUnit.SECONDS);
                    log.info("请求企业微信，获取accessToken成功有效时间为:{}", expires_in + "分钟");
                    return accessToken;
                } catch (Exception e) {
                    log.error("获取token失败：{}", e);
                }
            }
            log.info("从Redis缓存中获取的accessToken");
            return redisCache.getCacheObject(QY_WX_TOKEN_kEY);
        }
    }

[access_token]: https://blog.csdn.net/LIU_ZHAO_YANG/article/details/126769802