In the last article, we introduced Eureka cluster environment construction. In this paper, we use Eureka as the registry to achieve a case, the case structure is as follows
1. Start Eureka service
Each of our deployed Eureka points to the following command to start the Eureka service
./server.sh start
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2. Build the Provider service
1. Create a SpringBoot project
2. Modify the POM file
Add dependencies. Note that Eureka dependencies do not need to add “-server”
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-config</artifactId> < version > 1.4.5. RELEASE < / version > < / dependency > < the dependency > < groupId > org. Springframework. Cloud < / groupId > < artifactId > spring - the cloud - starter - eureka < / artifactId > < version > 1.4.6. RELEASE < / version > < / dependency > < / dependencies > <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Dalston.SR5</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement>Copy the code3. Modify the startup class
Open the primary key of the Eureka client in the header of the startup class
4. Add configuration information
Add the following information to application.properties
Name =eureka-provider server.port=9090 Point to another registry eureka. Client. ServiceUrl. DefaultZone = http://eureka1:8761/eureka/, http://eureka2:8761/eureka/Copy the codeNotice For Eureka1 and Eureka2, you need to configure mappings in the hosts file as follows
5. Add services
Create a pojo
package com.dpb.springcloud_eureka_provider.pojo; /** * @program: Springcloud-eureka-provider * @description: UserBean * @author: 2019-05-28 17:31 */ public class User { private int userid; private String username; private int userage; public int getUserid() { return userid; } public void setUserid(int userid) { this.userid = userid; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public int getUserage() { return userage; } public void setUserage(int userage) { this.userage = userage; } public User(int userid, String username, int userage) { this.userid = userid; this.username = username; this.userage = userage; } public User() { } }Copy the codeCreating a Controller
/** * @program: Springcloud -eureka-provider * @description: service provider * @author: Bobbo -provider * @create: 2019-05-28 17:30 */ @RestController public class UserController { @RequestMapping("/user") public List<User> getUsers(){ List<User> list = new ArrayList<>(); list.add(new User(1,"zhangsan",20)); list.add(new User(2,"lisi",22)); list.add(new User(3,"wangwu",20)); return list; }}Copy the code6. Start the service
Start the service and we can see our service provider in the registry
Build Consumer services
Consumers create services, much like providers.
1. Create projects
2. The pom
<dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-config</artifactId> < version > 1.4.5. RELEASE < / version > < / dependency > < the dependency > < groupId > org. Springframework. Cloud < / groupId > < artifactId > spring - the cloud - starter - eureka < / artifactId > < version > 1.4.6. RELEASE < / version > < / dependency > < / dependencies > <dependencyManagement> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>Dalston.SR5</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement>Copy the code3. Start the class
4. Configuration file
Name =eureka-consumer server.port=9091 Point to another registry eureka. Client. ServiceUrl. DefaultZone = http://eureka1:8761/eureka/, http://eureka2:8761/eureka/Copy the code5. Complete the service invocation
The consumer completes the invocation of the server-side service
In the service code
/** * @program: Springcloud-eureka-consumer * @description: User's business processing * @author: bobo ~ ~ * @create: 2019-05-28 17:43 */ @service public class UserService {/** ** Ribbon load Balancing * LoadBalancerClient */ @autoWired Private LoadBalancerClient LoadBalancerClient; Public List<User> getUsers(){ServiceInstance Encapsulates basic service information, such as the IP address and port number. ServiceInstance si = this.loadBalancerClient.choose("eureka-provider"); StringBuilder sb = new StringBuilder(); sb.append("http://") .append(si.getHost()) .append(":") .append(si.getPort()) .append("/user"); // SpringMVC RestTemplate RestTemplate rt = new RestTemplate(); ParameterizedTypeReference<List<User>> type = new ParameterizedTypeReference<List<User>>() {}; ResponseEntity<List<User>> response = rt.exchange(sb.tostring (), httpmethod.get,null,type); List<User> list = response.getBody(); return list; }}Copy the code| interface | instructions |
|---|---|
| LoadBalancerClient | Load balancers can obtain the IP address and host information of the corresponding service based on the service name |
| RestTemplate | Rest service templates that can be used to invoke services |
Controller code
/** * @program: Springcloud-eureka-consumer * @description: user controller * @author: Bobo * @create: 2019-05-28 17:40 */ @RestController public class UserController { @Autowired private UserService userService; @RequestMapping("/consumer") public List<User> getUsers(){ return this.userService.getUsers(); }}Copy the code6. Start the service
After starting the service, we can discover the service in the Eureka registry.
Request the consumer’s interface to retrieve the data provided by the service provider.
Case success