How to use Java to develop a configuration center application based on Spring Cloud Config

How to use Java to develop a configuration center application based on Spring Cloud Config

Introduction:
In a distributed system, configuration management is a very important link . The traditional configuration file management method has many disadvantages. For example, configuration files are scattered in various modules, and modifications to the configuration require redeployment. The emergence of the configuration center solves these problems and makes configuration management more convenient and efficient. Spring Cloud Config is an excellent configuration center solution. This article will introduce how to use Java to develop a configuration center application based on Spring Cloud Config, and attach specific code examples.

1. Environment preparation
Before starting development, we need to prepare the following environment:

1. JDK environment, it is recommended to use JDK8 and above.
2. Maven environment, used to manage project dependencies and builds.
3. Spring Boot environment, the latest stable version is 2.3.4.RELEASE.
4. Spring Cloud Config environment, the latest stable version is Hoxton.SR8.

2. Create a Spring Boot project
First, we need to create a Spring Boot project as a container for the configuration center application. You can use Spring Initializr (https://start.spring.io/) to quickly create projects. Select the appropriate dependencies, such as Web, Config Server, etc., download the generated project package, and import it into the IDE.

3. Configuration file
In the created Spring Boot project, we need to perform some basic configurations.

1. application.properties
   In the src/main/resources directory, create the application.properties file and configure basic properties such as service ports.

server.port=8888
spring.application.name=config-server
spring.cloud.config.server.git.uri=https://github.com/{your_git_repo}.git
spring.cloud.config.server.git.clone-on-start=true

Among them, server.port is used to set the port number of the service. spring.application.nameSet the application name, which will be used as the service name of the configuration center. spring.cloud.config.server.git.uriSet the address of the Git warehouse. Here we take GitHub as an example. spring.cloud.config.server.git.clone-on-start means that the configuration of the Git repository will be cloned locally when the application starts.

2. pom.xml
   In the pom.xml file of the Spring Boot project, you need to add the dependency of Spring Cloud Config.

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-config-server</artifactId>
</dependency>

4. Create Config Server
Next, we need to create a server for the configuration center.

1. Create ConfigServerApplication class
   In the src/main/java directory, create a ConfigServerApplication class and add @Configuration and @EnableConfigServer annotations.

@Configuration
@EnableConfigServer
public class ConfigServerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConfigServerApplication.class, args);
    }
}

2. Start the configuration center
   Run the main method of ConfigServerApplication to start the configuration center server. If everything goes well, the log will show that the configuration center has been successfully started and is listening on port 8888.

5. Create a configuration warehouse
In the configuration center, we need to create a Git warehouse to manage configuration files. Taking GitHub as an example, you can create a new warehouse on GitHub and add configuration files to the warehouse.

1. Create configuration file
   In the Git repository, create a config folder and add a configuration file named application.yml in it. The format of the configuration file can be yaml or properties. Here we take the yaml format as an example.

server:
  port: 8080

2. Submit the configuration file to the Git repository

6. Configuration using the configuration center
In applications that need to use the configuration center, we need to Some configurations to apply the configuration center configuration to the application.

1. Create the ConfigClientApplication class
   First, we need to create a ConfigClientApplication class as the entry point for applications that need to use configuration.

@SpringBootApplication
@RestController
@RefreshScope
public class ConfigClientApplication {

    @Autowired
    private ConfigurableApplicationContext applicationContext;

    @RequestMapping("/")
    public String hello() {
        return applicationContext.getEnvironment().getProperty("server.port");
    }

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

2. Configuring bootstrap.properties
   In the src/main/resources directory, create the bootstrap.properties file and configure some basic properties of the application.

spring.application.name=config-client
spring.cloud.config.uri=http://localhost:8888
management.endpoints.web.exposure.include=*

Among them, spring.application.name sets the application name, spring.cloud.config.uri sets the address of the configuration center, assuming that the configuration center The server runs locally.

3. Use configuration
   In the hello method of the ConfigClientApplication class, obtain the configuration in the configuration center through applicationContext.getEnvironment().getProperty("server.port") item.

7. Run the application
Run the main method of ConfigClientApplication to start the application, and then visit http://localhost:8080/ to see the configuration obtained through the configuration center.

Summary:
This article details how to use Java to develop a configuration center application based on Spring Cloud Config, and provides specific code examples. Through the configuration center, we can achieve centralized management and dynamic update of configuration, improving the maintainability and flexibility of the distributed system. I hope this article will be helpful to everyone’s study and practice.

The above is the detailed content of How to use Java to develop a configuration center application based on Spring Cloud Config. For more information, please follow other related articles on the PHP Chinese website!