springCloud之服务调用RestTemplate、OpenFeign

https://blog.csdn.net/qq_29752857/article/details/129220590

package com.test.config;
 
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
 
@Configuration
//@LoadBalancerClient(value = "userservice", configuration = LoadBalancerConfig.class)
public class BeanConfiguration {
    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

package com.test.service.impl;
 
 
import com.minos.entity.Book;
import com.minos.entity.Borrow;
import com.minos.entity.User;
import com.minos.entity.UserBorrowDetail;
import com.test.mapper.BorrowMapper;
import com.test.service.BorrowService;
import com.test.service.client.UserClient;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
 
import javax.annotation.Resource;
import java.util.List;
import java.util.stream.Collectors;
 
@Service
public class BorrowServiceImpl implements BorrowService {
 
    @Resource
    BorrowMapper mapper;
    @Resource
    RestTemplate restTemplate;
    @Resource
    UserClient userClient;
 
    @Override
    public UserBorrowDetail getUserBorrowDetailByUid(int uid) {
        List<Borrow> borrow = mapper.getBorrowsByUid(uid);
        //RestTemplate支持多种方式的远程调用
        //这里通过调用getForObject来请求其他服务，并将结果自动进行封装
        //获取User信息
        User user = restTemplate.getForObject("http://userService/user/" + uid, User.class);
        //User user = userClient.getUserById(uid);
        //获取每一本书的详细信息
        List<Book> bookList = borrow
                .stream()
                .map(b -> restTemplate.getForObject("http://bookService/book/" + b.getBid(), Book.class))
                .collect(Collectors.toList());
        return new UserBorrowDetail(user, bookList);
    }
}

<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-openfeign</artifactId>
 </dependency>

@EnableFeignClients

package com.test.service.client;
 
import com.minos.entity.User;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
 
//@FeignClient(value = "userService", fallback = UserFallbackClient.class)   //声明为userservice服务的HTTP请求客户端
@FeignClient(value = "userService")   //声明为userservice服务的HTTP请求客户端
public interface UserClient {
    //路径保证和其他微服务提供的一致即可
    @RequestMapping("/user/{uid}")
    User getUserById(@PathVariable("uid") int uid);  //参数和返回值也保持一致
}

package com.test.service.impl;
 
 
import com.minos.entity.Book;
import com.minos.entity.Borrow;
import com.minos.entity.User;
import com.minos.entity.UserBorrowDetail;
import com.test.mapper.BorrowMapper;
import com.test.service.BorrowService;
import com.test.service.client.UserClient;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
 
import javax.annotation.Resource;
import java.util.List;
import java.util.stream.Collectors;
 
@Service
public class BorrowServiceImpl implements BorrowService {
 
    @Resource
    BorrowMapper mapper;
    @Resource
    RestTemplate restTemplate;
    @Resource
    UserClient userClient;
 
    @Override
    public UserBorrowDetail getUserBorrowDetailByUid(int uid) {
        List<Borrow> borrow = mapper.getBorrowsByUid(uid);
        //RestTemplate支持多种方式的远程调用
        //这里通过调用getForObject来请求其他服务，并将结果自动进行封装
        //获取User信息
        //User user = restTemplate.getForObject("http://userService/user/" + uid, User.class);
        User user = userClient.getUserById(uid);
        //获取每一本书的详细信息
        List<Book> bookList = borrow
                .stream()
                .map(b -> restTemplate.getForObject("http://bookService/book/" + b.getBid(), Book.class))
                .collect(Collectors.toList());
        return new UserBorrowDetail(user, bookList);
    }
}