Spring Cloud API Gateway路由异常：student-service访问返回404求助

我使用Spring Cloud开发微服务，项目包含college-service、student-service、eureka-server和api-gateway四个服务。通过API Gateway调用业务服务时，college-service可正常访问，但调用student-service时出现404 NotFound错误。测试URL及结果如下：

以下是各服务的代码及配置信息：

College Service #

实体类 #

public class College {
    private String clgId;
    private String clgName;
    private String clgCity;

    List<Student> students;

    public College(String clgId, String clgName, String clgCity, List<Student> students) {
        this.clgId = clgId;
        this.clgName = clgName;
        this.clgCity = clgCity;
        this.students = students;
    }

    public College(String clgId, String clgName, String clgCity) {
        this.clgId = clgId;
        this.clgName = clgName;
        this.clgCity = clgCity;
    }
   
    // getter and setter
}

public class Student {
    private Long stId;
    private String stName;
    private String stEmail;
    private String clgId;

    public Student(Long stId, String stName, String stEmail, String clgId) {
        super();
        this.stId = stId;
        this.stName = stName;
        this.stEmail = stEmail;
        this.clgId = clgId;
    }

    // getter and setter
}

Controller #

@RestController
@RequestMapping("/college")
public class CollegeController {
    @Autowired
    private CollegeService collegeService;

    @Autowired
    private RestTemplate restTemplate;

    @RequestMapping(value = "/{clgId}", method = RequestMethod.GET)
    public ResponseEntity<College> getColleges(@PathVariable("clgId") String clgId) {
        College college = collegeService.getCollege(clgId);
        List student = restTemplate.getForObject("http://student-service/college/student/" + college.getClgId(),
                List.class);
        college.setStudents(student);
        return ResponseEntity.ok(college);
    }
}

application.yml #

server:
  port: 9001
  
spring:
  application:
    name: college-service
    
eureka:
  instance:
    hostname: localhost

Student Service #

实体类 #

public class Student {
    private Long stId;
    private String stName;
    private String stEmail;
    private String clgId;

    public Student(Long stId, String stName, String stEmail, String clgId) {
        super();
        this.stId = stId;
        this.stName = stName;
        this.stEmail = stEmail;
        this.clgId = clgId;
    }

    // getter and setter
}

Controller #

@RestController
@RequestMapping("/college")
public class StudentCotroller {

    @Autowired
    private StudentService studentService;

    @RequestMapping(value = "/student/{clgId}", method = RequestMethod.GET)
    public ResponseEntity<List<Student>> getStudents(@PathVariable("clgId") String clgId) {
        return ResponseEntity.ok(studentService.getStudents(clgId));
    }

}

application.yml #

server:
  port: 9002
  
spring:
  application:
    name: student-service
    
eureka:
  instance:
    hostname: localhost

Eureka Server #

application.yml #

server:
  port: 8761

eureka:
  instance:
    hostname: localhost
  client:
    registerWithEureka: false
    fetchRegistry: false
  server:
    waitTimeInMsWhenSyncEmpty: 0

API Gateway Service #

application.yml #

server:
  port: 9003
  
eureka:
  instance:
    hostname: localhost

spring:
  application:
    name: api-gateway
  cloud:
    gateway:
      routes:
      - id: college-service
        uri: lb://college-service
        predicates:
        - Path=/college/**
      - id: student-service
        uri: lb://student-service
        predicates:
        - Path=/student/**

问题原因 #

API Gateway的路由配置存在匹配逻辑错误：

• student-service的接口路径为/college/student/{clgId}，但网关配置的student-service路由断言是Path=/student/**，无法匹配/college/student/CLG01请求。
• 该请求会被college-service的路由Path=/college/**匹配，转发到college-service，但college-service无对应接口，因此返回404。

解决方案 #

调整API Gateway的路由顺序和断言规则，让/college/student/**的请求优先转发到student-service：

修改后的API Gateway application.yml：

server:
  port: 9003
  
eureka:
  instance:
    hostname: localhost

spring:
  application:
    name: api-gateway
  cloud:
    gateway:
      routes:
      - id: student-service
        uri: lb://student-service
        predicates:
        - Path=/college/student/**
      - id: college-service
        uri: lb://college-service
        predicates:
        - Path=/college/**

调整后：

• 访问http://localhost:9003/college/student/CLG01时，会先匹配到student-service的路由，转发到对应接口返回200。
• 访问http://localhost:9003/college/CLG01时，匹配college-service的路由，正常返回结果。

另外确认student-service已正确注册到Eureka Server（从直接访问测试结果看注册状态正常）。

内容的提问来源于stack exchange，提问作者Faheem azaz Bhanej