[] Spring "Hello World"

0, written in the preceding words this article, in a simple example, describes spring's loading and fetching of Java classes through containers.in the following we can see that there is a Java class coder, we did not manually call new to instantiate, but from the spring container applicationcontext to get the instantiation of the class object。
1. Build a spring project with Maven

  
 

   
  

  
<dependencies>
   
  

  
 <dependency>
   
  

  
 <groupId>org.springframework</groupId>
   
  

  
 <artifactId>spring-context</artifactId>
   
  

  
 <version>4.3.16.RELEASE</version>
   
  

  
 </dependency>
   
  

  
</dependencies>
  
 

Using MAVEN to build a project, Dependency,ide automatically downloads associated spring-related core packages, such as: 2, to create a simple Java class by spring's official offer.

  
 

   
  

  
public class Coder {
   
  

  
 private String name;
   
  

  
 private int age;
   
  

  

   
  

  
 public void print(){
   
  

  
 System.out.println("Hello World");
   
  

  
 }
   
  

  

   
  

  
 public String getName() {
   
  

  
 return name;
   
  

  
 }
   
  

  

   
  

  
 public void setName(String name) {
   
  

  
 this.name = name;
   
  

  
 }
   
  

  

   
  

  
 public int getAge() {
   
  

  
 return age;
   
  

  
 }
   
  

  

   
  

  
 public void setAge(int age) {
   
  

  
 this.age = age;
   
  

  
 }
   
  

  
}
  
 

3. Create a spring configuration file for idea, Pom.xml has already configured spring dependencies, so when creating a new spring configuration file, you can create the most basic configuration file directly from idea: Then configure the Java class Bean:

  
 

   
  

  
<?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="Coder" class="Dulk.learn.spring.Coder"></bean>
   
  

  

   
  

  
</beans>
  
 

4, initialize the container, get the instance spring provides a variety of ways to initialize containers, the most common of which are two:

• Beanfactory, early JavaBean factory class implementation ( not recommended )
• ApplicationContext, the extension of beanfactory, provides more functions, such as internationalization processing, bean automatic assembly, etc.

beanfactory：

  
 

   
  

  
public class Test {
   
  

  
 public static void main(String[] args) {
   
  

  
 Beanfactory
   
  

  
 ResourcePatternResolver rpt = new PathMatchingResourcePatternResolver();
   
  

  
 Resource resource = rpt.getResource("/applicationContext.xml");
   
  

  
 BeanFactory bf = new XmlBeanFactory(resource);
   
  

  
 Coder coder = (Coder) bf.getBean("coder");
   
  

  
 coder.print();
   
  

  
 }
   
  

  
}
  
 

ApplicationContext：

  
 

   
  

  
public class Test {
   
  

  
 public static void main(String[] args) {
   
  

  
 ApplicationContext
   
  

  
 ApplicationContext ac = new ClassPathXmlApplicationContext("/applicationContext.xml");
   
  

  
 Coder coder = (Coder) ac.getBean("coder");
   
  

  
 coder.print();
   
  

  
 }
   
  

  
}
  
 

[] Spring "Hello World"