Spring 的 HelloWord

一、环境

• spring-framework-5.1.14.RELEASE
• jdk1.8
• Maven3.6.4

二、用Maven创建项目

创建maven-archetype-quickstart项目

mvn archetype:generate -DgroupId=abc.lei.le -DartifactId=Spring3-Example -DarchetypeArtifactId=maven-archetype-quickstart

三、 编辑 pom.xml，加入 spring 依赖

<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/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>abc.lei.le</groupId>
  <artifactId>Spring3-Example</artifactId>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>Spring3-Example</name>
  <url>http://maven.apache.org</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>
        <spring.version>5.1.14.RELEASE</spring.version>
    </properties>
    
  <dependencies>

  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>${spring.version}</version>
  </dependency>

    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

四、创建一个Spring Bean

一个简单的spring bean如下

package abc.lei.le.helloworld;

public class Helloworld {

  private String name;

  public void setName(String n){
    this.name = n;
  }

  public void printHello(){
    System.out.println("The first Spring :hello" + name);
  }
}

五、创建Spring Bean的配置文件

创建文件SpringBeans.xml，配置bean如下。文件位于src/main/resources下

<?xml version = "1.0" encoding = "UTF-8"?>
<beans xmlns = "http://www.springframework.org/schema/beans"
       xmlns:xsi = "http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation = "http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
    <bean id = "helloBean" class = "abc.lei.le.helloworld.Helloworld">
        <property name = "name" value = "你好666666呀"/>
    </bean>
</beans>

六、创建测试App

package abc.lei.le;

import abc.lei.le.helloworld.Helloworld;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class App{

  private static ApplicationContext context;

  public static void main(String[] args){
    context = new ClassPathXmlApplicationContext("SpringBeans.xml");

    Helloworld obj = (Helloworld) context.getBean("helloBean");
    obj.printHello();
  }
}

运行代码

mvn compile

mvn exec:java -Dexec.mainClass="abc.lei.le.App"