本篇文章给大家分享的是有关怎么在SpringCloud中使用Feign调用服务,小编觉得挺实用的,因此分享给大家学习,希望大家阅读完这篇文章后可以有所收获,话不多说,跟着小编一起来看看吧。
使用Spring Cloud Feign
创建一个SpringBoot工程,作为服务调用方
1.pom.xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
spring-cloud-starter-feign加入了feign的依赖
2.启动类
@EnableFeignClients
@EnableDiscoveryClient
@SpringBootApplication
public class FeignConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(FeignConsumerApplication.class, args);
}
}
@EnableFeignClients:开启Spring Cloud Feign的支持功能
3.服务层
@FeignClient("hello-service")
public interface HelloService {
@RequestMapping(value = "/hello", method = RequestMethod.GET)
String hello();
}
@FeignClient(“hello-service”):制定服务名来绑定服务
注:服务名不区分大小写
@RequestMapping:指定调用服务中的具体方法
4.Controller层
@Controller
public class ConsumerController {
@Autowired
private HelloService helloService;
@RequestMapping(value = "/feign-consumer", method = RequestMethod.GET)
@ResponseBody
public String helloConsumer() {
return helloService.hello();
}
}
在方法中调用这个绑定了hello-service服务接口的客户端向该服务发起/hello接口的调用
5.配置类
server.port=9001
spring.application.name=feign-consumer
eureka.client.serviceUrl.defaultZone=http://localhost:1111/eureka/
启动程序以后,在浏览器中输入http://localhost:9001/feign-consumer出现下图:
- 提升使用,带参数的请求
在具体业务中的接口会比之前程序的复杂得多,这里介绍一下Feign对集中不同形式参数的绑定方法。有@RequestParam、@RequestHeader、@RequestBody
1.改造服务提供类的Service层,添加几个方法
@RequestMapping(value = "/hello1", method = RequestMethod.GET)
@ResponseBody
public String hello(@RequestParam String name) {
return "hello " + name;
}
@RequestMapping(value = "/hello2", method = RequestMethod.GET)
@ResponseBody
public User hello(@RequestHeader String name, @RequestHeader Integer age) {
return new User(name, age);
}
@RequestMapping(value = "/hello3", method = RequestMethod.POST)
@ResponseBody
public String hello(@RequestBody User user) {
return "Hello " + user.getName() + ", " + user.getAge();
}
2.添加一个javabean
public class User {
private String name;
private Integer age;
public User() {
}
public User(String name, Integer age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Integer getAge() {
return age;
}
public void setAge(Integer age) {
this.age = age;
}
@Override
public String toString() {
return "User{" +
"name='" + name + '\'' +
", age=" + age +
'}';
}
}
3.修改服务调用类的接口
@RequestMapping(value = "/hello1", method = RequestMethod.GET)
String hello(@RequestParam("name") String name);
@RequestMapping(value = "/hello2", method = RequestMethod.GET)
User hello(@RequestHeader("name") String name, @RequestHeader("age") Integer age);
@RequestMapping(value = "/hello3", method = RequestMethod.POST)
String hello(@RequestBody User user);
这里在定义各参数绑定时@RequestParam、@RequestHeader等可以指定参数名称的注解,但它们的value不能少,否则会报错,这和SpringMVC中有一点不同
4.在服务调用类Controller层添加一个测试的接口
@RequestMapping(value = "/feign-consumer2", method = RequestMethod.GET)
@ResponseBody
public String helloConsumer2() {
String s2 = helloService.hello("dayday");
return s2;
}
启动以后访问浏览器:
以上就是怎么在SpringCloud中使用Feign调用服务,小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注天达云行业资讯频道。