Go Spring Annotations-@Configuration annotations, @Bean annotations, and configuring automatic scanning, bean scopes

1, @Configuration marked on the class, equivalent to the class as a spring XML configuration file, the <beans> role of: Configure the Spring container (application context)

Package Com.test.spring.support.configuration, @Configurationpublic class Testconfiguration {public    Testconfiguration () {        System.out.println ("Spring Container start initialization ... ");    }}

Equivalent:

<?xml version= "1.0" encoding= "UTF-8"? ><beans xmlns= "Http://www.springframework.org/schema/beans" xmlns: Xsi= "Http://www.w3.org/2001/XMLSchema-instance" xmlns:context= "Http://www.springframework.org/schema/context" Xmlns:jdbc= "Http://www.springframework.org/schema/jdbc" xmlns:jee= "Http://www.springframework.org/schema/jee" xmlns:tx= "Http://www.springframework.org/schema/tx" xmlns:util= "Http://www.springframework.org/schema/util" xmlns:task= "Http://www.springframework.org/schema/task" xsi:schemalocation= "http://www.springframework.org/ Schema/beans http://www.springframework.org/schema/beans/spring-beans-4.0.xsd http://www.springframework.org/ Schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd/HTTP WWW.SPRINGFRAMEWORK.ORG/SCHEMA/JDBC http://www.springframework.org/schema/jdbc/spring-jdbc-4.0.xsd/HTTP Www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.0.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd/http Www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd/HTTP Www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-4.0.xsd " Default-lazy-init= "false" ></beans>

The Main method is tested:

Package Com.test.spring.support.configuration;public class Testmain {public    static void Main (string[] args) {        @Configuration Annotated spring container load mode, replace Classpathxmlapplicationcontext        with Annotationconfigapplicationcontext ApplicationContext context = new Annotationconfigapplicationcontext (testconfiguration.class);        If the Spring-context.xml file is loaded:        //applicationcontext context = new Classpathxmlapplicationcontext (" Spring-context.xml ");}    }

As you can see from the results of running the main method, the spring container has started:

August11, :11 pm org. springframework. Contextannotation. Annotationconfigapplicationcontext preparerefresh Info: refreshing org. springframework. Context. Annotation. Annotationconfigapplicationcontext@203e25d3:startup Date [Thu : Each CST 2016] ; root of context hierarchyspring container start initialization ... 

2. The @Bean is labeled on the method (the method that returns an instance), equivalent to the spring XML configuration file <bean> , which functions as: registering the Bean object

Bean class:

Package Com.test.spring.support.configuration;public class Testbean {public    void SayHello () {        System.out.println ("Testbean sayHello ...");    Public String toString () {        return "username:" +this.username+ ", url:" +this.url+ ", Password:" +this.password;    }    public void Start () {        System.out.println ("Testbean initialization ... ");    }    public void CleanUp () {        System.out.println ("Testbean destroyed ... ");    }}

Configuration class:

Package Com.test.spring.support.configuration, @Configurationpublic class Testconfiguration {public        Testconfiguration () {            System.out.println ("Spring Container start initialization ... ");        }    @Bean Note Register Bean, you can specify initialization and destruction method    //@Bean (name= "Testnean", initmethod= "Start", destroymethod= "cleanUp")    @ Bean    @Scope ("prototype") public    Testbean Testbean () {        return new Testbean ();}    }

Main method Test class:

Package Com.test.spring.support.configuration;public class Testmain {public    static void Main (string[] args) {        ApplicationContext context = new Annotationconfigapplicationcontext (testconfiguration.class);        Get Bean        Testbean TB = Context.getbean ("Testbean");        Tb.sayhello ();    }}

Note:
(1), @Bean annotations on the method that returns the instance, if the name of the bean is not specified by @bean, the default is the same as the method name of the callout;

(2), @Bean annotations The default scope is a singleton singleton scope, which can be set as a prototype scope by @scope ("prototype");

(3), since the role of @bean is to register the bean object, you can fully use @component, @Controller, @Service, @Ripository and other annotations to register the bean, Of course, you need to configure @componentscan annotations for automatic scanning.

Bean class:

Package com.test.spring.support.configuration;//Add registered Bean annotations @componentpublic class Testbean {public    void SayHello () {        System.out.println ("Testbean sayHello ...");    }    Public String toString () {        return "username:" +this.username+ ", url:" +this.url+ ", Password:" +this.password;    }}

Configuration class:

• @Configuration//Add automatic scan annotations, basepackages for Testbean package path @componentscan (basepackages = " Com.test.spring.support.configuration ") public class Testconfiguration {public    testconfiguration () {        System.out.println ("Spring Container start initialization ... ");    }    How to cancel @bean annotation registration Bean/    /@Bean    //@Scope ("prototype")    //public Testbean Testbean () {    //  return New Testbean ();    //}}

The Main method test gets the Bean object:

public class Testmain {public    static void Main (string[] args) {        ApplicationContext context = new annotationconf Igapplicationcontext (testconfiguration.class);        Get Bean        Testbean TB = Context.getbean ("Testbean");        Tb.sayhello ();    }}

The SayHello () method is called normally.

(Original address: http://www.cnblogs.com/ilinuxer/p/6503161.html)

Go Spring annotations [email protected] annotations, @Bean annotations, and configuring automatic scanning, bean scopes