这篇文章主要介绍了spring怎么实现依赖注入DI的相关知识，内容详细易懂，操作简单快捷，具有一定借鉴价值，相信大家阅读完这篇spring怎么实现依赖注入DI文章都会有所收获，下面我们一起来看看吧。
spring依赖注入DI
1、创建一个maven项目
mvn archetype:generate -DarchetypeCatalog=internal2、修改pom.xml
引入需要的依赖，首先spring-context，还是spring-test，最后还有junit。
<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、添加类Person和Body
package com.xueyou.demo;import org.springframework.stereotype.Component;@Componentpublic class Person { public String getName() { return name; } public void setName(String name) { this.name = name; } private String name;}package org.xueyou.demo;import org.springframework.stereotype.Component;@Componentpublic class Body { public int getId() { return id; } public void setId(int id) { this.id = id; } private int id;}4、在配置类App中，添加ComponentScan
需要注意的是，这里需要指定扫描的包
package com.xueyou.demo;import org.springframework.context.annotation.ComponentScan;import org.springframework.context.annotation.Configuration;@Configuration@ComponentScan(basePackages = {"org.xueyou.demo","com.xueyou.demo"})public class App { public static void main(String[] args) { System.out.println("Hello World!"); }}5、新建一个测试类
package com.xueyou.demo;import org.junit.Assert;import org.junit.Test;import org.junit.runner.RunWith;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.test.context.ContextConfiguration;import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;import org.xueyou.demo.Body;@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration(classes = App.class)public class Springtest { @Autowired private Body body; @Autowired private Person person; @Test public void testBodyIsNull(){ Assert.assertNotNull(body); } @Test public void testPersonIsNull(){ Assert.assertNotNull(person); }}6、运行测试类
结果如下：
7、从运行结果中我们能看到
Person类和Student类已经被依赖注入到spring中，spring能够使用这两个类了。
spring-test依赖无法使用问题
<dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>4.3.7.RELEASE</version> <scope>test</scope></dependency>去掉
<scope>test</scope>关于“spring怎么实现依赖注入DI”这篇文章的内容就介绍到这里，感谢各位的阅读！相信大家对“spring怎么实现依赖注入DI”知识都有一定的了解，大家如果还想学习更多知识，欢迎关注编程网行业资讯频道。
