Spring Framework Learning Notes (10)

Configuring the Bean by annotations

Spring is able to automatically scan, detect and instantiate components with specific annotations from Classpath.

That is, the way to implement annotations is to configure a bean to meet 2 conditions:

1. Classes are labeled with specific components, such as: @Component, @Service, @Repository, @Controller
2. Add Bean-scan:<context:component-scan base-package= "Com.pfSoft.annotation" ></context to the configuration file: Component-scan>

The following example illustrates: The New people class, note that the namespace (the previous example has basically omitted the namespace part, but through the Bean-scan to implement annotation-based injection, the namespace is more important)

Package Com.pfsoft.annotation;import org.springframework.stereotype.Component; @Componentpublic class People { private string Name;private Integer age;/** *  * @return The name */public String getName () {return name;} /** * @param name the name to set */public void SetName (String name) {this.name = name;} /** *  * @return The Age */public Integer Getage () {return-age;} /** * @param age-The age-to set */public void Setage (Integer-age) {this.age = age;} /* (non-javadoc) * @see java.lang.object#tostring () */@Overridepublic String toString () {return ' people [name= ' + name + ' , age= "+ Age +"] ";}}

New interfaces and implementation classes:

Package Com.pfsoft.annotation.service;public interface Ipeoplemanservice {public Boolean adult (Integer age);

Package Com.pfsoft.annotation.service;import Org.springframework.stereotype.Service; @Service (value= " Peoplemanservice ") public class Peoplemanserviceimp implements Ipeoplemanservice {public Boolean adult (Integer age) { Boolean ret=false;if (age>=18) {ret=true;} return ret;}}

Test method:

public class Testannotation {applicationcontext ctx=null; @Beforepublic void init () {ctx=new  Classpathxmlapplicationcontext ("Spring-annotation.xml");} @Testpublic void Test () {people people= (people) Ctx.getbean ("People");p Eople.setage (8);p eople.setname ("PF"); System.out.println (people); Ipeoplemanservice service= (Ipeoplemanservice) Ctx.getbean ("Peoplemanservice"); if ( Service. Adult (People.getage ())) {System.out.println (Messageformat.format ("{0} adult, {1} years old", People.getname (), People.getage () )); }else {System.out.println (Messageformat.format ("{0} minor, only {1} years old", People.getname (), People.getage ()))}}

The output results are as follows:

People [NAME=PF, AGE=8]PF Minors, only 8 years old

Filtering in the configuration file

Resource-pattern Filter Implementation

<context:exclude-filter type= "annotation" expression= ""/> Child nodes represent target classes to be excluded
<context:include-filter type= "annotation" expression= ""/> Indicates the target class to be included

Spring Framework Learning Notes (10)