4-8 Spring Bean裝配之基於Java的容器-基於泛型的自動裝配

基於泛型的自動裝配

• 基於泛型的自動裝配是spring4中新增的內容。

泛型自動裝配例子：

public interface Store<T> {
}
public class IntegerStore implements Store<Integer> {

}
public class StringStore implements Store<String> {

}

package com.torey.beanannotation.javabased;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @ClassName：StoreConfig
 * @Description：
 * @author: Torey
 */
@Configuration
public class StoreConfig {
    @Autowired
    private Store<String> s1;
    @Autowired
    private Store<Integer> s2;

    @Bean
    public IntegerStore s2(){
        return new IntegerStore();
    }
    @Bean
    public StringStore s1(){
        StringStore ss=new StringStore();
        System.out.println("StringStore:"+ss.hashCode());
        return ss;
    }
    @Bean
    public Store stringStoreTest(){
        System.out.println("s1:" + s1.getClass().getName()+";s1.hashCode:"+s1.hashCode());
        System.out.println("s2:" + s2.getClass().getName());
        StringStore ss= new StringStore();
        System.out.println("stringStoreTest:"+ss.hashCode());
        return ss;

    }
}

package com.torey.springtest.base;

import org.junit.After;
import org.junit.Before;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.util.StringUtils;

/**
 * @ClassName：UnitTestBase
 * @Description：
 * @author: Torey
 */
public class UnitTestBase {
    public UnitTestBase(){}
    private String springXmlPath;
    private ClassPathXmlApplicationContext applicationContext;
    public UnitTestBase(String springXmlpath){
        this.springXmlPath=springXmlpath;
    }
    @Before
    public void before(){
        if (StringUtils.isEmpty(springXmlPath)) {
            springXmlPath="classpath*:spring-*.xml";
        }
        applicationContext= new ClassPathXmlApplicationContext(springXmlPath.split("[,\\s]"));
        applicationContext.start();
    }
    @After
   public void after(){
        applicationContext.destroy();
   }
   public Object getBean(String beanId){
       return applicationContext.getBean(beanId);
   }
}

package com.torey.springtest.bean;

import com.torey.beanannotation.javabased.Store;
import com.torey.springtest.base.UnitTestBase;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.BlockJUnit4ClassRunner;

/**
 * @ClassName：TestResources
 * @Description：
 * @author: Torey
 */
@RunWith(BlockJUnit4ClassRunner.class)
public class TestBeanAnnotation extends UnitTestBase {
    public TestBeanAnnotation(){
        super("classpath:spring-beanannotation.xml");
    }
  @Test
  public void testG(){
      Store store=(Store) super.getBean("stringStoreTest");
  }
}

Autowire擴展：自定義qualifier註解

CustomAutowireConfigurer

• CustomAutowireConfigurer是BeanFactoryPostProcessor的子類，通過它可以註冊自己的qualifier註解類型（即使沒有使用Spring的@Qualifier註解）

 <bean id="customAutowireConfigurer" class="org.springframework.beans.factory.annotation.CustomAutowireConfigurer">
        <property name="customQualifierTypes">
            <set>
                <value>example.CustomQualifier</value>
            </set>
        </property>
    </bean>

• 該AutowireCandidateResolver決定自動裝配的候選者：
  • 每個bean定義的autowire-candidate值
  • 任何< bean/ >中的default-autowire-candidates
  • @Qualifier註解及使用CustomAutowireConfigurer的自定義類型

根據慕課網 moocer老師的spring課程 整理