spring依赖注入知识点分享

<bean id="student" class="com.abc.di01.Student">
  <property name="age" value="20"/>
  <property name="name" value="张三"/>
  <property name="school" ref="mySchool"/>
</bean>

<!--直接给对应的构造方法参数赋值-->
<bean id="student" class="com.abc.di02.Student">
  <constructor-arg name="age" value="20"/>
  <constructor-arg name="name" value="李四"/>
  <constructor-arg name="school" ref="mySchool"/>
</bean>
<!--使用索引方式赋值-->
<bean id="student" class="com.abc.di02.Student">
  <constructor-arg index="0" value="李四"/>
  <constructor-arg index="1" value="20"/>
  <constructor-arg index="2" ref="mySchool"/>
</bean>
<!--直接省略索引下标，进行赋值-->
<bean id="student" class="com.abc.di02.Student">
  <constructor-arg value="李四"/>
  <constructor-arg value="20"/>
  <constructor-arg ref="mySchool"/>
</bean>

xmlns:p="http://www.springframework.org/schema/p"
xmlns:c=http://www.springframework.org/schema/c

<bean id="student" class="com.abc.di03.Student" p:age="19" p:name="小明" p:school-ref="mySchool"/>
<bean id="student" class="com.abc.di04.Student" c:age="16" c:name="小红" c:school-ref="mySchool"/>

<bean id="some" class="com.abc.di05.Some">
  <!--数组赋值-->
  <property name="names">
    <array>
      <value>张三</value>
      <value>李四</value>
      <value>王五</value>
    </array>
  </property>
  <!--List-->
  <property name="myList">
    <list>
      <value>河南</value>
      <value>河北</value>
    </list>
  </property>
  <property name="schools">
    <list>
      <ref bean="aynu"/>
      <ref bean="tsinghua"/>
    </list>
  </property>
  <!--set集合赋值-->
  <property name="mySets">
    <set>
      <value>本科</value>
      <value>硕士</value>
      <value>博士</value>
    </set>
  </property>
  <!--map集合赋值-->
  <property name="myMap">
    <map>
      <entry key="mobile" value="123456"/>
      <entry key="QQ" value="654321"/>
    </map>
  </property>
  <!--properties集合-->
  <property name="myPros">
    <props>
      <prop key="email">123456@qq.com</prop>
      <prop key="address">文明大道</prop>
    </props>
  </property>
</bean>

<property name="names" value="张三,李四">
  <!--<array>
    <value>张三</value>
    <value>李四</value>
    <value>王五</value>
  </array>-->
</property>

private String name;
private int age;
//域属性
private School school;//也需要有setter方法

<!--
  byType：同种类型的对象（包括子类的对象）只能有一个
  byName:注入的bean的id和域属性的属性名相同
-->
<bean id="student" class="com.abc.di06.Student" autowire="byName">
  <property name="age" value="20"/>
  <property name="name" value="张三"/>
</bean>

<bean id="school" class="com.abc.di06.MiddleSchool">
  <property name="sname" value="一中"/>
  <property name="address" value="文明大道"/>
</bean>

<!--首先定义一个类，注入属性，T调用Math类-->
<bean id="person" class="com.abc.di07.Person">
  <property name="pname" value="张三"/>
  <property name="page" value="#{T(java.lang.Math).random()*100}"/>
</bean>
<!--可以将person中的值注入到student中-->
<bean id="student" class="com.abc.di07.Student">
  <property name="name" value="#{person.pname}"/>
  <!--<property name="age" value="#{person.page>30?30:person.page}"/>-->
  <property name="age" value="#{person.computeAge()}"/>
</bean>

<!--注册组件扫描器-->
<context:component-scan base-package="com.abc.di01"/>

//在注解中如果只有"value"一个参数，可以将value省略，只留下value的值；
@Component("mySchool")
public class School {
  @Value("一中")
  private String sname;

  public void setSname(String sname) {
    this.sname = sname;
  }
}

@Component(value = "student")
public class Student {
  @Value("小刘")
  private String name;
  @Value("18")
  private int age;
  //byType方式自动注入
  //@Autowired
  //byName方式自动注入
  //@Qualifier("mySchool")
  private School school;

  public void setName(String name) {
    this.name = name;
  }

  public void setAge(int age) {
    this.age = age;
  }

  public void setSchool(School school) {
    this.school = school;
  }
}