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2024-07-09 03:14:09   217人阅读

依赖注入两种方式： 构造函数和属性
 package x.y; 
  public class Foo { 




      public Foo(Bar bar, Baz baz) { 
          // ... 
      } 




  } 
 <beans> 
      <bean id="foo" class="x.y.Foo"> 
          <constructor-arg ref="bar"/> 
          <constructor-arg ref="baz"/> 
      </bean> 




      <bean id="bar" class="x.y.Bar"/> 




      <bean id="baz" class="x.y.Baz"/> 
  </beans> 




 public class ExampleBean { 




      // Number of years to calculate the Ultimate Answer 
      private int years; 




      // The Answer to Life, the Universe, and Everything 
      private String ultimateAnswer; 




      public ExampleBean(int years, String ultimateAnswer) { 
          this.years = years; 
          this.ultimateAnswer = ultimateAnswer; 
      } 




  } 




 <bean id="exampleBean" class="examples.ExampleBean"> 
      <constructor-arg type="int" value=http://www.mamicode.com/"7500000"/>
      <constructor-arg type="java.lang.String" value=http://www.mamicode.com/"42"/>
  </bean> 
  <bean id="exampleBean" class="examples.ExampleBean"> 
      <constructor-arg index="0" value=http://www.mamicode.com/"7500000"/>
      <constructor-arg index="1" value=http://www.mamicode.com/"42"/>
  </bean> 
<bean id="exampleBean" class="examples.ExampleBean"> 
      <constructor-arg name="years" value=http://www.mamicode.com/"7500000"/>
      <constructor-arg name="ultimateanswer" value=http://www.mamicode.com/"42"/>
  </bean> 
注意使用名称匹配，必须保证你的代码在debug 模式下编译了，否则spring 找不到名称。
还有另一种解决办法，就是使用java 注解：如下
  package examples; 




  public class ExampleBean { 




      // Fields omitted 




      @ConstructorProperties({"years", "ultimateAnswer"}) 
      public ExampleBean(int years, String ultimateAnswer) { 
          this.years = years; 
          this.ultimateAnswer = ultimateAnswer; 
      } 




  } 


构造函数 依赖多用于强制性的配置。
set 方法 多用于 可选择的属性配置。
public class ExampleBean { 




      private AnotherBean beanOne; 
      private YetAnotherBean beanTwo; 
      private int i; 




      public void setBeanOne(AnotherBean beanOne) { 
          this.beanOne = beanOne; 
      } 




      public void setBeanTwo(YetAnotherBean beanTwo) { 
          this.beanTwo = beanTwo; 
      } 




      public void setIntegerProperty(int i) { 
          this.i = i; 
      } 




  } 
引用ref
  <bean id="exampleBean" class="examples.ExampleBean"> 
      <!-- setter injection using the nested <ref/> element --> 
      <property name="beanOne"> 
          <ref bean="anotherExampleBean"/> 
      </property> 




      <!-- setter injection using the neater ref attribute --> 
      <property name="beanTwo" ref="yetAnotherBean"/> 
      <property name="integerProperty" value=http://www.mamicode.com/"1"/>
  </bean> 




  <bean id="anotherExampleBean" class="examples.AnotherBean"/> 
  <bean id="yetAnotherBean" class="examples.YetAnotherBean"/> 




  -----------------------------------常用配置
<bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy- 
  method="close"> 
      <!-- results in a setDriverClassName(String) call --> 
      <property name="driverClassName" value=http://www.mamicode.com/"com.mysql.jdbc.Driver"/>
      <property name="url" value=http://www.mamicode.com/"jdbc:mysql://localhost:3306/mydb"/>
      <property name="username" value=http://www.mamicode.com/"root"/>
      <property name="password" value=http://www.mamicode.com/"masterkaoli"/>
  </bean> 


p-namespace:
<beans xmlns="http://www.springframework.org/schema/beans" 
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
      xmlns:p="http://www.springframework.org/schema/p" 
      xsi:schemaLocation="http://www.springframework.org/schema/beans 
      http://www.springframework.org/schema/beans/spring-beans.xsd"> 




      <bean id="myDataSource" class="org.apache.commons.dbcp.BasicDataSource" 
          destroy-method="close" 
          p:driverClassName="com.mysql.jdbc.Driver" 
          p:url="jdbc:mysql://localhost:3306/mydb" 
          p:username="root" 
          p:password="masterkaoli"/> 




  </beans> 






---------------------
<bean id="mappings" 
      class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> 




      <!-- typed as a java.util.Properties --> 
      <property name="properties"> 
          <value> 
              jdbc.driver.className=com.mysql.jdbc.Driver 
              jdbc.url=jdbc:mysql://localhost:3306/mydb 
          </value> 
      </property> 
  </bean> 


------------引用父亲bean


 <bean id="accountService" <-- bean name is the same as the parent bean --> 
      class="org.springframework.aop.framework.ProxyFactoryBean"> 
      <property name="target"> 
          <ref parent="accountService"/> <!-- notice how we refer to the parent bean --> 
      </property> 
      <!-- insert other configuration and dependencies as required here --> 
  </bean> 


-----------内嵌bean
 <bean id="outer" class="..."> 
      <!-- instead of using a reference to a target bean, simply define the target bean 
   inline --> 
      <property name="target"> 
          <bean class="com.example.Person"> <!-- this is the inner bean --> 
              <property name="name" value=http://www.mamicode.com/"Fiona Apple"/>
              <property name="age" value=http://www.mamicode.com/"25"/>
          </bean> 
      </property> 
  </bean> 


----------------------集合bean
 <list/>, <set/>, <map/>, and <props/>元素设置 Java 集合类型 List, Set, Map, and Properties
<bean id="moreComplexObject" class="example.ComplexObject"> 
      <!-- results in a setAdminEmails(java.util.Properties) call --> 
      <property name="adminEmails"> 
          <props> 
              <prop key="administrator">administrator@example.org</prop> 
              <prop key="support">support@example.org</prop> 
              <prop key="development">development@example.org</prop> 
          </props> 
      </property> 
      <!-- results in a setSomeList(java.util.List) call --> 
      <property name="someList"> 
          <list> 
              <value>a list element followed by a reference</value> 
              <ref bean="myDataSource" /> 
          </list> 
      </property> 
      <!-- results in a setSomeMap(java.util.Map) call --> 
      <property name="someMap"> 
          <map> 
              <entry key="an entry" value=http://www.mamicode.com/"just some string"/>
              <entry key ="a ref" value-ref="myDataSource"/> 
          </map> 
      </property> 
      <!-- results in a setSomeSet(java.util.Set) call --> 
      <property name="someSet"> 
          <set> 
              <value>just some string</value> 
              <ref bean="myDataSource" /> 
          </set> 
      </property> 
  </bean> 
map的或者value  set 的value  还可以在
是下面这些元素
  bean | ref | idref | list | set | map | props | value | null 


合并映射  


<beans> 
      <bean id="parent" abstract="true" class="example.ComplexObject"> 
          <property name="adminEmails"> 
              <props> 
                  <prop key="administrator">administrator@example.com</prop> 
                  <prop key="support">support@example.com</prop> 
              </props> 
          </property> 
      </bean> 
      <bean id="child" parent="parent"> 
          <property name="adminEmails"> 
              <!-- the merge is specified on the child collection definition --> 
              <props merge="true"> 
                  <prop key="sales">sales@example.com</prop> 
                  <prop key="support">support@example.co.uk</prop> 
              </props> 
          </property> 
      </bean> 
  <beans> 
你知道的，child 的adminEmails 属性里包含了 父子 两个的属性集合。


强类型映射


 public class Foo { 




      private Map<String, Float> accounts; 




      public void setAccounts(Map<String, Float> accounts) { 
          this.accounts = accounts; 
      } 
  } 




  <beans> 
      <bean id="foo" class="x.y.Foo"> 
          <property name="accounts"> 
              <map> 
                  <entry key="one" value=http://www.mamicode.com/"9.99"/>
                  <entry key="two" value=http://www.mamicode.com/"2.75"/>
                  <entry key="six" value=http://www.mamicode.com/"3.99"/>
              </map> 
          </property> 
      </bean> 
  </beans> 


-----------------------空
<bean class="ExampleBean"> 
      <property name="email" value=http://www.mamicode.com/""/>
  </bean> 
<bean class="ExampleBean"> 
      <property name="email"> 
          <null/> 
      </property> 
  </bean> 
------p-namespace
 <beans xmlns="http://www.springframework.org/schema/beans" 
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
      xmlns:p="http://www.springframework.org/schema/p" 
      xsi:schemaLocation="http://www.springframework.org/schema/beans 
          http://www.springframework.org/schema/beans/spring-beans.xsd"> 




      <bean name="classic" class="com.example.ExampleBean"> 
          <property name="email" value=http://www.mamicode.com/"foo@bar.com"/>
      </bean> 




      <bean name="p-namespace" class="com.example.ExampleBean" 
          p:email="foo@bar.com"/> 
  </beans> 


---c_namespace 


<beans xmlns="http://www.springframework.org/schema/beans" 
      xmlns:xsi= "http://www.w3.org/2001/XMLSchema-instance" 
      xmlns:c= "http://www.springframework.org/schema/c" 
      xsi:schemaLocation= "http://www.springframework.org/schema/beans 
          http://www.springframework.org/schema/beans/spring-beans.xsd"> 




      <bean id= "bar" class="x.y.Bar"/> 
      <bean id= "baz" class="x.y.Baz"/> 




      <!-- traditional declaration --> 
      <bean id= "foo" class="x.y.Foo"> 
          <constructor-arg ref= "bar"/> 
          <constructor-arg ref= "baz"/> 
          <constructor-arg value= http://www.mamicode.com/"foo@bar.com"/>
      </bean> 




      <!-- c-namespace declaration --> 
      <bean id= "foo" class="x.y.Foo" c:bar-ref= "bar" c:baz-ref= "baz" c:email= "foo@bar.com"/> 


<bean id="foo" class="x.y.Foo" c:_0-ref= "bar" c:_1-ref= "baz"/> 


  </beans> 


---depend-on  bean初始化前，被依赖的bean 先初始化。 
 <bean id="beanOne" class="ExampleBean" depends-on="manager,accountDao"> 
      <property name="manager" ref="manager" /> 
  </bean> 




  <bean id="manager" class="ManagerBean" /> 
  <bean id="accountDao" class="x.y.jdbc.JdbcAccountDao" /> 




---懒加载（容器启动时候，不愿意生成实例）




bean 级别
  <bean id="lazy" class="com.foo.ExpensiveToCreateBean" lazy-init="true"/> 
  <bean name="not.lazy" class="com.foo.AnotherBean"/> 
容器级别
<beans default-lazy-init="true"> 
      <!-- no beans will be pre-instantiated... --> 
  </beans> 




自动装配
byName byType no constructor


autowire-candidate  false 


-------------lookup method 


 <!-- a stateful bean deployed as a prototype (non-singleton) --> 
  <bean id="command" class="fiona.apple.AsyncCommand" scope="prototype"> 
      <!-- inject dependencies here as required --> 
  </bean> 




  <!-- commandProcessor uses statefulCommandHelper --> 
  <bean id="commandManager" class="fiona.apple.CommandManager"> 
      <lookup-method name="createCommand" bean="command"/> 
  </bean> 


-----repace 


<bean id="myValueCalculator" class="x.y.z.MyValueCalculator"> 
      <!-- arbitrary method replacement --> 
      <replaced-method name="computeValue" replacer="replacementComputeValue"> 
          <arg-type>String</arg-type> 
      </replaced-method> 
  </bean> 




  <bean id="replacementComputeValue" class="a.b.c.ReplacementComputeValue"/> 


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