Spring 容器可以管理 singleton 作用域 Bean 的生命周期，容器能夠跟蹤 Bean 實例的創建、銷毀。管理 Bean 生命周期行為主要有兩個時機：　　注入 Bean 的依賴關系之后　　即將銷毀 Bean 之間

有三種方式可以在 Bean 的所有屬性設置成功后執行特定的行為：　　實現 org.springframework.beans.factory.InitializingBean 接口　　使用 init-method 屬性　　使用 @PostConstruct 注解

Bean 的定義：

public class ExampleBean implements InitializingBean {        private String field1;    private String field2;        public void setField1(String field1) {        this.field1 = field1;        System.out.println("field1 was set.");    }        public void setField2(String field2) {        this.field1 = field2;        System.out.println("field2 was set.");    }        public ExampleBean() {        System.out.println("In ExampleBean Constructor.");    }    public void afterPropertiesSet() throws Exception {        System.out.println("All properties were set.");    }    }

Spring 配置：

<bean id="eb" class="com.huey.dream.bean.ExampleBean">    <property name="field1" value=""/>    <property name="field2" value=""/></bean>

測試方法：

@Testpublic void testLifecycle() throws Exception {    applicationContext appCtx =           new ClassPathxmlApplicationContext("applicationContext.xml");}

結果輸出：

In ExampleBean Constructor.field1 was set.field2 was set.All properties were set.

Bean 的定義：

public class ExampleBean  {        private String field1;    private String field2;        public void setField1(String field1) {        this.field1 = field1;        System.out.println("field1 was set.");    }        public void setField2(String field2) {        this.field1 = field2;        System.out.println("field2 was set.");    }        public ExampleBean() {        System.out.println("In ExampleBean Constructor.");    }    public void init() throws Exception {        System.out.println("In init method.");    }    }

Spring 配置：

<bean id="eb" class="com.huey.dream.bean.ExampleBean" init-method="init">    <property name="field1" value=""/>    <property name="field2" value=""/></bean>

Bean 的定義：

public class ExampleBean  {        private String field1;    private String field2;        public void setField1(String field1) {        this.field1 = field1;        System.out.println("field1 was set.");    }        public void setField2(String field2) {        this.field1 = field2;        System.out.println("field2 was set.");    }        public ExampleBean() {        System.out.println("In ExampleBean Constructor.");    }        @PostConstruct    public void init() throws Exception {        System.out.println("In init method.");    }    }

Spring 配置：

<bean id="eb" class="com.huey.dream.bean.ExampleBean">    <property name="field1" value=""/>    <property name="field2" value=""/></bean>

與定制初始化行為類似，也有三種方式可以在 Bean 實例銷毀前執行特定的行為：　　實現 org.springframework.beans.factory.DisposableBean 接口　　使用 destroy-method 屬性　　使用 @PreDestroy 注解