(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner

  ApplicationContextInitializer接口在spring容器执行refreshed之前回调,实现方式有3种

  方式一:调用SpringApplication的addInitializers方法注册

  pom.xml

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
<?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>com.edu.spring</groupId>
    <artifactId>springboot</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>

    <name>springboot</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>
    
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.1.6.RELEASE</version>
                <scope>import</scope>
                <type>pom</type>
            </dependency>
        </dependencies>
    </dependencyManagement>
    
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

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

</project>
View Code

  MyApplicationContextInitializer.java,实现ApplicationContextInitializer接口

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;

public class MyApplicationContextInitializer implements
        ApplicationContextInitializer<ConfigurableApplicationContext> {

    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        // TODO Auto-generated method stub
        System.out.println("当前容器bean数量:"+applicationContext.getBeanDefinitionCount());
    }

}
View Code

  App.java,调用SpringApplication的addInitializers方法(可以有多个)

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class App 
{
    public static void main( String[] args )
    {
        SpringApplication app=new SpringApplication(App.class);
        app.addInitializers(new MyApplicationContextInitializer());
        ConfigurableApplicationContext context= app.run(args);
        context.close();
    }
}
View Code

  运行结果如下:

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner

   方式二:application.properties中配置context.initializer.classes属性(可以配置多个)

  application.properties

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
context.initializer.classes=com.edu.spring.springboot.MyApplicationContextInitializer,com.edu.spring.springboot.MyApplicationContextInitializer2
View Code

  MyApplicationContextInitializer2.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;

public class MyApplicationContextInitializer2 implements
        ApplicationContextInitializer<ConfigurableApplicationContext> {

    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        // TODO Auto-generated method stub
        System.out.println("app name:"+applicationContext.getApplicationName());
    }

}
View Code

  App.java,去掉addInitializers方法

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class App 
{
    public static void main( String[] args )
    {
        SpringApplication app=new SpringApplication(App.class);
        ConfigurableApplicationContext context= app.run(args);
        context.close();
    }
}
View Code

  运行结果如下:

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner

   方式三:使用spring.factories机制

  resources/META-INF/spring.factories

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
org.springframework.context.ApplicationContextInitializer=com.edu.spring.springboot.EchoApplicationContextInitializer
View Code

  EchoApplicationContextInitializer.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;

public class EchoApplicationContextInitializer implements
        ApplicationContextInitializer<ConfigurableApplicationContext> {

    public void initialize(ConfigurableApplicationContext applicationContext) {
        System.out.println("=============EchoApplicationContextInitializer=================");        
    }

}
View Code

  App.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class App 
{
    public static void main( String[] args )
    {
        SpringApplication app=new SpringApplication(App.class);
        ConfigurableApplicationContext context= app.run(args);
        context.close();
    }
}
View Code

  运行结果如下:

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner

   由于spring.factories机制会扫描所有工程里面的/META-INF/spring.factories文件,所以另建一个工程也可以运行,如下:

  新建core-bean

  pom.xml

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
<?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>com.edu.core</groupId>
    <artifactId>core-bean</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>

    <name>springboot</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>
    
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>4.3.2.RELEASE</version>
        </dependency>
    </dependencies>

</project>
View Code

  EchoApplicationContextInitializer.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.initializer;

import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;

public class EchoApplicationContextInitializer implements
        ApplicationContextInitializer<ConfigurableApplicationContext> {

    public void initialize(ConfigurableApplicationContext applicationContext) {
        System.out.println("=============core-bean:EchoApplicationContextInitializer=================");        
    }

}
View Code

  resources/META-INF/spring.factories

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
org.springframework.context.ApplicationContextInitializer=com.edu.initializer.EchoApplicationContextInitializer
View Code

  原工程的pom.xml文件引入core-bean坐标

  pom.xml

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
<?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>com.edu.spring</groupId>
    <artifactId>springboot</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>

    <name>springboot</name>
    <!-- FIXME change it to the project's website -->
    <url>http://www.example.com</url>
    
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.1.6.RELEASE</version>
                <scope>import</scope>
                <type>pom</type>
            </dependency>
        </dependencies>
    </dependencyManagement>
    
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.edu.core</groupId>
            <artifactId>core-bean</artifactId>
            <version>1.0.0</version>
        </dependency>
    </dependencies>

</project>
View Code

  运行原工程App.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class App 
{
    public static void main( String[] args )
    {
        SpringApplication app=new SpringApplication(App.class);
        ConfigurableApplicationContext context= app.run(args);
        context.close();
    }
}
View Code

  运行结果如下:

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner

   CommandLineRunner、ApplicationRunner是spring容器启动成功后最后的回调,@Order控制顺序,数字越小越先执行,请看示例:

  ServerSuccessReport.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import java.util.Arrays;

import org.springframework.boot.CommandLineRunner;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

@Order(1)
@Component
public class ServerSuccessReport implements CommandLineRunner {

    @Override
    public void run(String... args) throws Exception {
        // TODO Auto-generated method stub
        System.out.println("==========ServerSuccessReport1============"+Arrays.asList(args));
    }

}
View Code

  ServerSuccessReport2.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import java.util.Arrays;

import org.springframework.boot.CommandLineRunner;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

@Order(3)
@Component
public class ServerSuccessReport2 implements CommandLineRunner {

    @Override
    public void run(String... args) throws Exception {
        // TODO Auto-generated method stub
        System.out.println("==========ServerSuccessReport2============"+Arrays.asList(args));
    }

}
View Code

  StartedApplicationRunner.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import java.util.Arrays;

import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;

@Order(2)
@Component
public class StartedApplicationRunner implements ApplicationRunner {

    public void run(ApplicationArguments args) throws Exception {
        System.out.println("应用已经启动,参数为:"+Arrays.asList(args.getSourceArgs()));
    }

}
View Code

  App.java

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner
package com.edu.spring.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ConfigurableApplicationContext;

@SpringBootApplication
public class App 
{
    public static void main( String[] args )
    {
        SpringApplication app=new SpringApplication(App.class);
        ConfigurableApplicationContext context= app.run("aa","bb ");
        context.close();
    }
}
View Code

  运行结果如下:

(011)Spring Boot之回调接口ApplicationContextInitializer、CommandLineRunner、ApplicationRunner

   CommandLineRunner与ApplicationRunner的区别是CommandLineRunner参数是原始的,ApplicationRunner参数是对原始参数的封装。

 

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