Question

我在服务间通信负载平衡方面存在问题。

我使用spring（1.4.2），spring cloud with netflixOSS。

我有两个服务shoppingcart-service和user-service。

以下是来自shopppingcart-service app的ShoppingCartController：

@RestController
@RequestMapping("shoppingCarts")
public class ShoppingCartController extends AbstractRESTController<ShoppingCart, String>{

private ShoppingCartService shoppingCartSrevice;

@Autowired
public ShoppingCartController(ShoppingCartService service) {
    super(service);
    this.shoppingCartSrevice = service;
}

@RequestMapping(value = "{userId}/createShoppingCart", method = RequestMethod.POST)
ShoppingCart createShoppingCart(
        @RequestBody List<CartItem> items,
        @PathVariable(name = "userId") String userId
        ){

    Boolean userOK = shoppingCartSrevice.checkUser(userId);

    if(userOK != null)
        if(userOK)
            return shoppingCartSrevice.createShoppingCart(items, userId);

    return null;
}

@FeignClient("user-service")//the server.port property name, for the "server" service
public interface UserServiceClient {
    @RequestMapping(value = "users/checkUser", method = RequestMethod.POST)// the endpoint which will be balanced over
    Boolean checkUser(
            @RequestParam(name = "userId") String userId);// the method specification must be the same as for users/hello
}

}

＆＃34; checkUser＆＃34;

methosd来自ShoppingCartService类：

@Service
public class ShoppingCartService extends AbstractCRUDService<ShoppingCart, String>{

private ShoppingCartRepository shoppingCartRepository;
private RestTemplate restTemplate;

@Autowired
private UserServiceClient userServiceClient;// feign client

@Autowired
public ShoppingCartService(ShoppingCartRepository repo, RestTemplate restTemplate) {
    super(repo);
    this.shoppingCartRepository = repo;
    this.restTemplate = restTemplate;

}

/**
 * Method checks if the given user is registered and active
 * We use Ribbon and Feign to get data from user-service, load-balancing 
 * @param userId
 * @return
 */
@HystrixCommand(fallbackMethod="fallbackCheckUser")
public Boolean checkUser(String userId) {

    /*USING LOAD-BALANCING*/
     Boolean resp = userServiceClient.checkUser(userId);//HERE I GET THE EXCEPTION
     return resp;
}

public Boolean fallbackCheckUser(String userId){
    return true;
}

当我尝试执行checkUser（userId）@HystricsCommand方法时，我得到：java.lang.reflect.InvocationTargetException。

请帮助。

更新1：

shoppingcart-service pom.xml：

 <?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>rs.uns.acs.ftn</groupId>
    <artifactId>ShoppingCartService</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>ShoppingCartService</name>
    <description>Shopping Cart Service</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.4.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-mongodb</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.jglue.fluent-json</groupId>
            <artifactId>fluent-json</artifactId>
            <version>2.0.3</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Camden.SR2</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

Answer 1

Spring Cloud，Feign，Ribbon除了这些＆＃34; REST＆＃34;终点似乎不遵循建议的做法。

POST检查用户是否存在并不正常，POST通常用于创建资源，例如用户或产品。

POST到/..../{userId}/createShoppingCart看起来也不正确。在REST API设计，/ users，/ products，/ users / {id}和HTTP谓词（POST，PUT，PATCH，DELETE，GET，....）中建议使用名词代表那些＆＃34上的操作;名词＆＃34;：POST / users表示创建用户，PUT / products / {id}表示更新id为{id}的产品。通常不建议将动词作为URL的一部分。

正如@spencergibb所提到的，没有配置文件（application.yml或属性），源代码和有意义的堆栈跟踪，很难解决这个问题。

一个可能的问题可能是您的pom文件错过了<start-class>中的<properties>元素。

假设客户端执行失败：java.lang.reflect.InvocationTargetException

1 个答案: