Spring Use Tutorial (iii) NOTE 2

Use annotations when Bean has an association relationship between beans

• Automatic assembly of @Autowired annotations has a compatible typeThe single Bean attribute – constructors, normal fields (even non-public), all methods with parameters can be applied @Authwired Annotations– by default, all properties that use @Authwired annotations need to be set. When Spring can't find an exception is thrown when the matching Bean assembly property is If a property is allowed to not be set, you can set the Required property of the @Authwired annotation is false– By default, automatic assembly by type will not work when there are multiple type-compatible beans in the IOC container. At this point you can @QualifierThe name of the Bean is provided in the note. Spring allows each other @Qualifiter The name of the injected Bean specified by the input parameter of the– @Authwired annotations can also be applied to Array Typeattribute, Spring will automatically assemble all matching beans. – @Authwired annotations can also be applied to the Collection Properties, Spring reads the type information for the collection, and then automatically assembles all of the compatible bean.– @Authwired annotations in Java.util.Map, if the map has a key value of String, Spring automatically assembles a bean that is compatible with the map value type, at which point the bean's name is used as the key value

<?XML version= "1.0" encoding= "UTF-8"?><Beansxmlns= "Http://www.springframework.org/schema/beans"Xmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance"Xmlns:context= "Http://www.springframework.org/schema/context"xsi:schemalocation= "Http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd Http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.0.xsd ">        <!--Specify packages scanned by the spring IOC container -        <!--Resource-pattern Scan a specified resource -        <!--<context:component-scan base-package= "com.test.spring.annotation" resource-pattern= "Controller/*.class "></context:component-scan> -                <!--exclude-filter child nodes Specify the components that exclude those specified expressions -        <!--include-filter child nodes contain components of those expressions and need to be configured Use-default-filters to False -        <Context:component-scanBase-package= "Com.test.spring.annotation" >         <!--<context:exclude-filter type= "annotation" expression= "Org.springframework.stereotype.Controller"/>             <context:include-filter type= "Annotation" expression= "Org.springframework.stereotype.Controller"/>  -             <!---<context:exclude-filter type= "assignable" expression= "Com.test.spring.annotation.TestObject"/> <context:include-filter type= "assignable" expression= "Com.test.spring.annotation.TestObject"/&G             T  -        </Context:component-scan></Beans>

     Public Static voidMain (string[] args) {ApplicationContext con=NewClasspathxmlapplicationcontext ("Beans_annocation.xml");//testobject to= (testobject) Con.getbean ("Testobject");//System.out.println (to);//        //userservice ser= (userservice) Con.getbean ("UserService");//System.out.println (Ser);//        //Usercontroller ucon= (Usercontroller) Con.getbean ("Usercontroller");        System.out.println (Ucon); Ucon.execute ();//USERREPOSITORYIMLPL ur= (USERREPOSITORYIMLPL) Con.getbean ("Userrepository");//System.out.println (UR);            }

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 PackageCom.test.spring.annotation.controller;Importorg.springframework.beans.factory.annotation.Autowired;ImportOrg.springframework.stereotype.Controller;ImportCom.test.spring.annotation.service.UserService; @Controller Public classUsercontroller {@AutowiredPrivateUserService UserService; //@Autowired can be placed on a method with parameters.     Public voidSetuserservice (UserService userservice) { This. UserService =UserService; }     Public voidExecute () {System.out.println ("Usercontroller");            Userservice.add (); }}

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 PackageCom.test.spring.annotation.service;Importorg.springframework.beans.factory.annotation.Autowired;ImportOrg.springframework.beans.factory.annotation.Qualifier;ImportOrg.springframework.stereotype.Service;Importcom.test.spring.annotation.repository.UserRepository; @Service Public classUserService {@Autowired @Qualifier ("Userrepository")//specify which bean to assemble    Privateuserrepository userrepository; //can unload parameters before     Public voidSetuserrepository (@Qualifier ("Userrepository") Userrepository userrepository) { This. Userrepository =userrepository; }     Public voidAdd () {System.out.println ("UserService's Add");    Userrepository.save (); }}

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 Packagecom.test.spring.annotation.repository;Importorg.springframework.beans.factory.annotation.Autowired;Importorg.springframework.stereotype.Repository;ImportCom.test.spring.annotation.TestObject;//annotations can be identified by Value property values, and the bean's name in the IOC container@Repository ("Userrepository") Public classUserrepositoryimlplImplementsuserrepository{@Autowired (Required=false)    PrivateTestobject to;  Public voidSave () {System.out.println ("Save to Implement Interface"); }     }

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Spring Use Tutorial (iii) NOTE 2