Zuul of spring cloud: service gateway

Keywords: Java Spring Maven Apache

The use of Zuul in Web projects is shown above< Using Zuul in SpringBoot >, the following example is Zuul's use in Spring Cloud.

Development tool: IntelliJ idea February 3, 2019

I. server side

1. Create project

Create a new spring boot project named "zuul Eureka server" in IDEA, select 2.1.10 for spring boot version, and check spring cloud discovery - > Eureka server in the dependency interface.
The complete content of pom.xml is as follows:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.10.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>zuul-eureka-server</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>zuul-eureka-server</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR4</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </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>${spring-cloud.version}</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>

2. Modify the configuration application.yml

Modify the port number to 8761; cancel the registration of your own information to Eureka server, and do not retrieve the registration information from Eureka server.

server:
  port: 8761
eureka:
  client:
    register-with-eureka: false
    fetch-registry: false

3. Modify startup code

Add annotation @ EnableEurekaServer

package com.example.zuuleurekaserver;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@SpringBootApplication
@EnableEurekaServer
public class ZuulEurekaServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(ZuulEurekaServerApplication.class, args);
    }

}

II. Service provider

1. Create project

Create a new spring boot project in IDEA, with the exception of the name "zuul provider", and the other steps are the same as above.

2. Modify the configuration application.yml

server:
  port: 8000
spring:
  application:
    name: zuul-provider
eureka:
  instance:
    hostname: localhost
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

3. Add an entity class User.java

package com.example.zuulprovider;

public class User {
    String name;
    Integer 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;
    }
}

4. Modify startup code

package com.example.zuulprovider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableEurekaClient
@RestController
public class ZuulProviderApplication {

    public static void main(String[] args) {
        SpringApplication.run(ZuulProviderApplication.class, args);
    }

    @RequestMapping(value="/user/{name}", produces = MediaType.APPLICATION_JSON_VALUE)
    public User user(@PathVariable String name) {
        User u = new User();
        u.setName(name);
        u.setAge(30);
        return u;
    }
}

III. service caller

1. Create project

Create a new spring boot project named "zuul invoker" in IDEA. Select 2.1.10 for the spring boot version. In the dependency interface, check spring cloud discovery - > Eureka server, spring cloud Routing - > openfeign.
The complete content of pom.xml is as follows:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.10.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>zuul-invoker</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>zuul-invoker</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR4</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-openfeign</artifactId>
        </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>${spring-cloud.version}</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>

2. Modify the configuration application.yml

server:
  port: 9000
spring:
  application:
    name: zuul-invoker
eureka:
  instance:
    hostname: localhost
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

3. Add an entity class User.java

package com.example.zuulinvoker;

public class User {
    String name;
    Integer 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;
    }
}

4. Add a client interface UserClient.java

package com.example.zuulinvoker;

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

//Declare the service name of the call
@FeignClient("zuul-provider")
public interface UserClient {
    @RequestMapping(method = RequestMethod.GET, value = "/user/{name}")
    User getUser(@PathVariable("name") String name);
}

5. Modify the startup code CloudInvokerApplication.java

Annotate @ EnableEurekaClient and @ EnableFeignClients

package com.example.zuulinvoker;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients
public class ZuulInvokerApplication {

    public static void main(String[] args) {
        SpringApplication.run(ZuulInvokerApplication.class, args);
    }

}

6. Add controller InvokerController.java

package com.example.zuulinvoker;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class InvokerController {
    @Autowired
    private UserClient userClient;

    @RequestMapping(value = "/invokeUser/{name}", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
    public User invokeUser(@PathVariable String name){
        User user = userClient.getUser(name);
        return user;
    }
}

IV. gateway Zuul

1. Create project
Create a new spring boot project named zuul gateway in IDEA. Select 2.1.10 for the spring boot version. Check spring cloud discovery - > Eureka server, spring cloud Routing - > zuul in the dependency interface.
The complete content of pom.xml is as follows:

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.10.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>zuul-gateway</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>zuul-gateway</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.SR4</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-zuul</artifactId>
        </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>${spring-cloud.version}</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>

2. Modify startup code

Add annotation @ EnableZuulProxy

package com.example.zuulgateway;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.zuul.EnableZuulProxy;

@SpringBootApplication
@EnableZuulProxy
public class ZuulGatewayApplication {

    public static void main(String[] args) {
        SpringApplication.run(ZuulGatewayApplication.class, args);
    }

}

3. Modify the configuration application.yml

Register the gateway project to Eureka server;
Declare that all / user / * * requests will be forwarded to the service with Id zuul invoker for processing.

server:
  port: 8080
spring:
  application:
    name: zuul-gateway
eureka:
  instance:
    hostname: localhost
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/
zuul:
  routes:
    user:
      path: /user/**
      serviceId: zuul-invoker

Five, test

1. Start the server.
Browser access http://localhost:8761 /, normal
2. Start service provider
Browser visit http://localhost:8000/user / Xiaoming
Page output: {"name": "Xiaoming", "age":30}
3. Start the service caller.
Browser visit http://localhost:9000/invokeUser / Xiaoming
Page output: {"name": "Xiaoming", "age":30}
4. Start the gateway
http://localhost:8080/user/invokeUser / Xiaoming
Page output: {"name": "Xiaoming", "age":30}
Thus, it can be seen that it was successfully forwarded and processed.

Posted by D_tunisia on Wed, 20 Nov 2019 06:58:16 -0800