Spring 4.0-the most basic injection

Spring is very useful, which is related to his injection, today, a brief talk about spring's basic injection, the great god please drift over.

1. Add MAVEN Support

  　　 <Dependency>            <groupId>Org.springframework</groupId>            <Artifactid>Spring-context</Artifactid>            <version>4.0.2.RELEASE</version>     </Dependency> 

The basic injection, as long as this one dependency can be, I'm pro-test.

2. Write several test classes

　　Suppose a scenario is convenient for code logic

　　

 package   Com.cnblogs.yjmyzz.domain;  public  abstract  class   computer { public  abstract  void   Showinfo ();}  

 Package Com.cnblogs.yjmyzz.domain;  Public class extends Computer {    @Override    publicvoid  showinfo () {        System.out.println ( "\tapple MAC book");}    }

 package   Com.cnblogs.yjmyzz.domain;  public  class   ThinkPad extends   computer {@Override  public  void      Showinfo () {System.out.println ( "\tlenovo ThinkPad" 

 package   Com.cnblogs.yjmyzz.domain;  public  abstract  class   Pet { public  abstract  void   Welcomemetohome ();}  

 Package Com.cnblogs.yjmyzz.domain;  Public class extends Pet {    @Override    publicvoid  welcomemetohome () {        System.out.println ( "\twang! wang! " );    }}

 PackageCom.cnblogs.yjmyzz.domain;Importjava.util.List; Public classProgrammer {PrivateString name; PrivatePet Pet; PrivateList<computer>computers;  Public voidsetName (String name) { This. Name =name; }     PublicList<computer>getcomputers () {returncomputers; }     Public voidSetcomputers (list<computer>computers) {         This. Computers =computers; }     Public voidSetpet (Pet pet) { This. Pet =Pet; }     Public voidShow () {System.out.print ("My name is" +name); System.out.print (", and I have" + computers.size () + "Computer" + (Computers.size () > 1? " S ":" ") +": ");        System.out.println ();  for(computer c:computers) {c.showinfo (); } System.out.println ("And I have a pet, everyday,when I go home, it'll welcome me by");    Pet.welcomemetohome (); }}

3, spring configuration file, here is the most basic configuration file, the rest of the configuration please add yourself

<?XML version= "1.0" encoding= "UTF-8"?><Beansxmlns= "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" >    <BeanID= "Jimmy"class= "Com.cnblogs.yjmyzz.domain.Programmer">        < Propertyname= "Name"value= "Jimmy.yang"/>        < Propertyname= "Pet"ref= "Wangcai"/>        < Propertyname= "Computers">            <List>                <refBean= "T60"/>                <refBean= "Macbook_pro"/>            </List>        </ Property>    </Bean>    <BeanID= "T60"class= "Com.cnblogs.yjmyzz.domain.ThinkPad"/>    <BeanID= "Macbook_pro"class= "Com.cnblogs.yjmyzz.domain.MacBook"/>    <BeanID= "Wangcai"class= "Com.cnblogs.yjmyzz.domain.Dog"/></Beans>

In this configuration file Simplebeans.xml, there are 4 bean instances configured, which are instantiated by the spring container (by default, singleton mode instantiation), and are kept in the container, when needed, Can be manually obtained by ApplicationContext's Getbean method

4. Test injection

For convenience, you need to write a tool class Springutils

 Packagecom.cnblogs.yjmyzz.utils;ImportOrg.springframework.context.ApplicationContext;ImportOrg.springframework.context.support.ClassPathXmlApplicationContext; Public classSpringutils {Private StaticApplicationContext ApplicationContext; Private StaticApplicationContext GetContext () {if(ApplicationContext = =NULL) {ApplicationContext=NewClasspathxmlapplicationcontext ("Simplebeans.xml"); }        returnApplicationContext; }     Public Static<T> T Getbean (class<t>Clazz, String beanname) {        returnGetContext (). Getbean (Beanname, clazz); }}

You can then use this tool class to get the injected object instance through Getbean.

 Package com.cnblogs.yjmyzz.test; Import Com.cnblogs.yjmyzz.domain.Programmer; Import com.cnblogs.yjmyzz.utils.SpringUtils; Import org.junit.Test;  Public class testspring {    @Test    publicvoid  testsimpleinject () {        Programmer Jimmy=  Springutils.getbean (Programmer.  Class, "Jimmy");        Jimmy.show ();    }}

The above code from my myeclipse copied out, pro-Test available, please contact me where in doubt.

Spring 4.0-the most basic injection