• Spring中Bean的生命周期


    #准备工作
    最近刚开始看韩顺平老师讲的Spring基础,感觉听起来还是感觉比较好,也就教程中的案例做了实践,接下来记录一下,Spring中Bean的生命周期。

    Spring的下载地址(我使用的是3.2.4):http://repo.springsource.org/libs-release-local/org/springframework/spring/

    ①创建工程
    首先,用IDE创建一个Java工程,在工程目录下创建lib目录,复制需要引用的jar包并添加到ClassPath,因为我用的是Intellij,可能操作上与Eclipse有些不同。
    ②添加项目依赖Jar包
    这个版本和教程中讲的2.5.5也有差异,主要是下载来的jar包中没有一个完整的包可以引用,只有一个个分开的jar包,这就使没有接触过Spring的我有些迷茫,
    因为包很多,不知道哪些需要哪些不需要,查了一下资料,说是引用spring-core-3.2.4.RELEASE和spring-beans-3.2.4.RELEASE就够了,但是经过实践,还
    需要引入spring-context-3.2.4.RELEASE、spring-expression-3.2.4.RELEASE和写日志的包commons-logging-1.1.1(需要单独下载)。
    结论(需要引用的Jar包):
    spring-core-3.2.4.RELEASE | spring-beans-3.2.4.RELEASE | spring-context-3.2.4.RELEASE | spring-expression-3.2.4.RELEASE | commons-logging-1.1.1
    ③创建applicationContext.xml文件
    到这一步又开始迷茫了,搜索一下找到复制过来,Intellij检查到没有使用的引用都是灰色的,所以就删除了未使用的,结果为:

    <?xml version="1.0" encoding="utf-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
    
    </beans>

    ④创建类文件
    User.java

     1 package com.spring.pojo;
     2 
     3 import org.springframework.beans.BeansException;
     4 import org.springframework.beans.factory.*;
     5 import org.springframework.context.ApplicationContext;
     6 import org.springframework.context.ApplicationContextAware;
     7 
     8 public class User implements BeanNameAware, BeanFactoryAware, ApplicationContextAware, InitializingBean, DisposableBean {
     9 
    10     private String name;
    11     // private String gender;
    12     // private Work service;
    13 
    14     public User() {
    15         System.out.println("①Constructor -> invoked");
    16     }
    17 
    18     public User(String name) {// , String gender, Work service) {
    19         this.name = name;
    20         // this.gender = gender;
    21         // this.service = service;
    22     }
    23 
    24     public String getName() {
    25         return name;
    26     }
    27 
    28     public void setName(String name) {
    29         System.out.println("①setName -> invoked");
    30         this.name = name;
    31     }
    32 
    33     /**
    34     public String getGender() {
    35         return gender;
    36     }
    37 
    38     public void setGender(String gender) {
    39         this.gender = gender;
    40     }
    41 
    42     public Work getService() {
    43         return service;
    44     }
    45 
    46     public void setService(Work service) {
    47         this.service = service;
    48     }
    49      */
    50 
    51     /**
    52      * init-method
    53      */
    54     public void initBean() {
    55         System.out.println("①initBean -> invoked");
    56     }
    57 
    58     public void show() {
    59         System.out.println("①" + this.name); // + ":" + this.gender + "
    " + service.getStatus());
    60     }
    61 
    62     @Override
    63     public void setBeanName(String s) {
    64         System.out.println("①" + s);
    65     }
    66 
    67     @Override
    68     public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
    69         System.out.println("①" + applicationContext);
    70     }
    71 
    72     @Override
    73     public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
    74         System.out.println("①" + beanFactory);
    75         Work workService = (Work) beanFactory.getBean("work");
    76         String status = workService.getStatus();
    77         System.out.println("②" + status);
    78     }
    79 
    80     @Override
    81     public void afterPropertiesSet() throws Exception {
    82         System.out.println("①afterPropertiesSet -> invoked");
    83     }
    84 
    85     @Override
    86     public void destroy() throws Exception {
    87         System.out.println("①DisposableBean's destroy -> invoked");
    88     }
    89 
    90     public void beforeDestroy() {
    91         System.out.println("①beforeDestroy -> invoked");
    92     }
    93 }

    Work.java

     1 package com.spring.pojo;
     2 
     3 import org.springframework.beans.BeansException;
     4 import org.springframework.beans.factory.*;
     5 import org.springframework.context.ApplicationContext;
     6 import org.springframework.context.ApplicationContextAware;
     7 
     8 public class Work implements BeanNameAware, BeanFactoryAware, ApplicationContextAware, InitializingBean, DisposableBean {
     9 
    10     public String name;
    11     public String age;
    12 
    13     public Work() {
    14         System.out.println("②Constructor -> invoked");
    15     }
    16 
    17     public Work(String name, String age) {
    18         this.name = name;
    19         this.age = age;
    20     }
    21 
    22     public String getName() {
    23         return name;
    24     }
    25 
    26     public void setName(String name) {
    27         System.out.println("②setName -> invoked");
    28         this.name = name;
    29     }
    30 
    31     public String getAge() {
    32         return age;
    33     }
    34 
    35     public void setAge(String age) {
    36         this.age = age;
    37     }
    38 
    39     public String getStatus() {
    40         return this.name + ":" + this.age;
    41     }
    42 
    43     public void initMethod() {
    44         System.out.println("②initMethod -> invoked");
    45     }
    46 
    47     @Override
    48     public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
    49         System.out.println("②" + applicationContext);
    50     }
    51 
    52     @Override
    53     public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
    54         System.out.println("②" + beanFactory);
    55     }
    56 
    57     @Override
    58     public void setBeanName(String s) {
    59         System.out.println("②" + s);
    60     }
    61 
    62     @Override
    63     public void destroy() throws Exception {
    64         System.out.println("②destroy -> invoked");
    65     }
    66 
    67     @Override
    68     public void afterPropertiesSet() throws Exception {
    69         System.out.println("②afterPropertiesSet");
    70     }
    71 
    72     public void destroyMethod() {
    73         System.out.println("②destroyMethod -> invoked");
    74     }
    75 }

    BeanProcessor.java

     1 package com.spring.pojo;
     2 
     3 import org.springframework.beans.BeansException;
     4 import org.springframework.beans.factory.config.BeanPostProcessor;
     5 
     6 public class BeanProcessor implements BeanPostProcessor {
     7 
     8     @Override
     9     public Object postProcessBeforeInitialization(Object o, String s) throws BeansException {
    10         System.out.println("postProcessBeforeInitialization -> invoked");
    11         return o;
    12     }
    13 
    14     @Override
    15     public Object postProcessAfterInitialization(Object o, String s) throws BeansException {
    16         System.out.println("postProcessAfterInitialization -> invoked");
    17         return o;
    18     }
    19 }

    UserTest.java

     1 package com.spring.pojo;
     2 
     3 import com.spring.pojo.User;
     4 import org.springframework.context.support.AbstractApplicationContext;
     5 import org.springframework.context.support.ClassPathXmlApplicationContext;
     6 
     7 public class UserTest {
     8 
     9     public static void main(String[] args) {
    10         AbstractApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
    11         User service = (User) context.getBean("user");
    12         service.show();
    13     }
    14 }

    applicationContext.xml

    <?xml version="1.0" encoding="utf-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">
    
        <bean id="user" class="com.spring.pojo.User"
              scope="prototype"
              init-method="initBean" destroy-method="beforeDestroy">
            <property name="name" value="祁连山"/>
            <!-- <property name="gender" value="男"/>
            <property name="service" ref="workService"/> -->
        </bean>
    
        <bean id="work" class="com.spring.pojo.Work"
            scope="prototype">
            <property name="name" value="android开发"/>
            <property name="age" value="三年"/>
        </bean>
    
        <bean id="beanProcessor" class="com.spring.pojo.BeanProcessor"/>
    </beans>

    ⑤测试结果:
    ①Constructor -> invoked
    ①setName -> invoked
    ①user
    ①org.springframework.beans.factory.support.DefaultListableBeanFactory@3fcd000a: defining beans [user,work,beanProcessor]; root of factory hierarchy
    ②Constructor -> invoked
    ②setName -> invoked
    ②work
    ②org.springframework.beans.factory.support.DefaultListableBeanFactory@3fcd000a: defining beans [user,work,beanProcessor]; root of factory hierarchy
    ②org.springframework.context.support.ClassPathXmlApplicationContext@7c4633e7: startup date [Sun Nov 29 13:26:05 CST 2015]; root of context hierarchy
    postProcessBeforeInitialization -> invoked
    ②afterPropertiesSet
    postProcessAfterInitialization -> invoked
    ②android开发:三年
    ①org.springframework.context.support.ClassPathXmlApplicationContext@7c4633e7: startup date [Sun Nov 29 13:26:05 CST 2015]; root of context hierarchy
    postProcessBeforeInitialization -> invoked
    ①afterPropertiesSet -> invoked
    ①initBean -> invoked
    postProcessAfterInitialization -> invoked
    ①祁连山

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  • 原文地址:https://www.cnblogs.com/magics/p/5004663.html
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