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This article mainly introduces spring how to achieve dependency injection DI related knowledge, the content is detailed and easy to understand, simple and fast operation, has a certain reference value, I believe you will have something to gain after reading this spring how to achieve dependency injection DI article, let's take a look at it.

Spring dependency injection DI1, create a maven project mvn archetype:generate-DarchetypeCatalog=internal2, modify pom.xml

Introduce the required dependencies, first spring-context, then spring-test, and finally junit.

UTF-8 4.3.7.RELEASE junit junit 4.12 test org.springframework spring-context ${springframework.version} org.springframework spring-test ${springframework.version} org.apache.maven.plugins maven-compiler-plugin 1.8 1.8 utf-8 Maven-assembly-plugin 3.0.0 com.xueyoucto.xueyou.App jar-with-dependencies Make-assembly package single 3 、 Add classes Person and Bodypackage 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. In the configuration class App, add ComponentScan

It is important to note that the scanned package needs to be specified here.

Package com.xueyou.demo;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!");}} 5, create a new test class 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. Run the test class

The results are as follows:

7. We can see from the running results

The Person class and the study class have been injected into spring, and spring can use them.

The spring-test dependency cannot use the problem org.springframework spring-test 4.3.7.RELEASE test

Remove

This is the end of test's article on "how spring implements dependency injection DI". Thank you for reading! I believe you all have a certain understanding of "how to achieve dependency injection DI in spring". If you want to learn more, you are welcome to follow the industry information channel.

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