spring——依赖注入DI(main函数方式)

spring——依赖注入DI(main函数方式)

虽然题目上说的是main函数方式，但是更精确的说，应该是从java配置中加载spring的ApplicationContext。上一篇文章介绍了如何通过spring-test的方式进行spring的测试（http://blog.csdn.net/wild46cat/article/details/71055262），本篇文章主要介绍通过main函数作为配置入口使用spring。

好，下面上货。
1、首先创建maven仓库。
mvn archetype:generate -DarchetypeCatalog=internal

2、添加pom.xml依赖。

<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<springframework.version>4.3.7.RELEASE</springframework.version>
</properties>

<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${springframework.version}</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.springframework/spring-test -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${springframework.version}</version>
</dependency>

</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>utf-8</encoding>
</configuration>
</plugin>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.0.0</version>
<configuration>
<archive>
<manifest>
<mainClass>com.xueyoucto.xueyou.App</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>make-assembly</id> <!-- this is used for inheritance merges -->
<phase>package</phase> <!-- bind to the packaging phase -->
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>

3、添加Person类和Body类

package com.xueyou.demo;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.xueyou.demo.Body;

@Component
public class Person {

@Autowired
private Body body;

public void showMyBody(){
body.setId(100);
System.out.println(body.getId());
}

}

package org.xueyou.demo;

import org.springframework.stereotype.Component;

@Component
public class Body {
public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}

private int id;

}

4、在main函数所在的类中配置spring扫描的包。

package com.xueyou.demo;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

/**
* Hello world!
*/
@Configuration
@ComponentScan(basePackages = {"org.xueyou.demo","com.xueyou.demo"})
public class App {

public static void main(String[] args) {
System.out.println("Hello World!");
ApplicationContext applicationContext = new AnnotationConfigApplicationContext(com.xueyou.demo.App.class);
Person p = applicationContext.getBean(Person.class);
p.showMyBody();

}
}

5、看一下类所在的包的关系。



6、运行结果：