2-Spring Bean management

table of Contents

Spring Bean Management

Spring Bean Management

Spring factory class

1.spring factory class management

### direct log messages to stdout ###
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log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

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log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=c\:mylog.log
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log4j.appender.file.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

### set log levels - for more verbose logging change 'info' to 'debug' ###

log4j.rootLogger=info, stdout

    @Test
    /**
     * Spring的方式实现
     */
    public void demo2(){
        // 创建Spring的工厂
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        // 通过工厂获得类:
        UserService userService = (UserService) applicationContext.getBean("userService");

        userService.sayHello();
    }

    @Test
    /**
     * 读取磁盘系统中的配置文件
     */
    public void demo3(){
        // 创建Spring的工厂类:
        ApplicationContext applicationContext = new FileSystemXmlApplicationContext("c:\\applicationContext.xml");
        // 通过工厂获得类:
        UserService userService = (UserService) applicationContext.getBean("userService");

        userService.sayHello();
    }

2.Spring of Bean Management (XML way)

1. instantiated class constructor (no default parameter)

/**
 * Bean的实例化的三种方式：采用无参数的构造方法的方式
 */
public class Bean1 {
    public Bean1(){
        System.out.println("Bean1被实例化了...");
    }
}

* * *
public class SpringDemo2 {
    @Test
    public void demo1(){
        // 创建工厂
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        // 通过工厂获得类的实例:
        Bean1 bean1 = (Bean1)applicationContext.getBean("bean1");
    }
 }

* * *
<!--第一种：无参构造器的方式-->
 <bean id="bean1" class="com.imooc.ioc.demo2.Bean1"/>

Example 2. Use of a static factory method (simple factory pattern)

public class Bean2 {

}

* * *
/**
 * Bean2的静态工厂
 */
public class Bean2Factory {

    public static Bean2 createBean2(){
        System.out.println("Bean2Factory的方法已经执行了...");
        return new Bean2();
    }
}

* * *

public class SpringDemo2 {
    @Test
    public void demo2(){
        // 创建工厂
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        // 通过工厂获得类的实例:
        Bean2 bean2 = (Bean2)applicationContext.getBean("bean2");
    }
}

* * *

<!--第二种：静态工厂的方式-->
<bean id="bean2" class="com.imooc.ioc.demo2.Bean2Factory" factory-method="createBean2"/>

The method of Example 3. Example of plant (factory methods)

/**
 * Bean的实例化三种方式：实例工厂实例化
 */
public class Bean3 {

}

* * *
/**
 * Bean3的实例工厂
 */
public class Bean3Factory {
    public Bean3 createBean3(){
        System.out.println("Bean3Factory执行了...");
        return new Bean3();
    }
}

* * *
public class SpringDemo2 {
    @Test
    public void demo3(){
    // 创建工厂
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        // 通过工厂获得类的实例:
        Bean3 bean3 = (Bean3)applicationContext.getBean("bean3");
    }
}

* * *
<bean id="bean3Factory" class="com.imooc.ioc.demo2.Bean3Factory"/>
 <bean id="bean3" factory-bean="bean3Factory" factory-method="createBean3"/>

3.bean common configuration

id and name

In general, the assembly of a bean, by an id attribute specified as the name of Bean, id attribute must be unique within the IOC container.

If the name Bean contains special characters, you will need to name attribute

class

class is used to set a full path name of the class, the main role is an example of class generating IOC container.

Bean scopes

1.singleton : there is only one container SpringIOC Bean instance, Bean by way of example the presence of a single embodiment.

2.prototype returns a new instance when getBean each call ():

3.request : each HTTP request will create a new Bean, that scope applies only to WebApplicationContext environment.

4.session : a share with a HTTP Session Bean, different Http Session Bean using different this scope apply only to WebAppliacationContext environment.

Bean of scope test

public class Person {

}

* * *
public class SpringDemo3 {
    @Test
    public void demo1(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        Person persion1 = (Person)applicationContext.getBean("person");
        Person persion2 = (Person)applicationContext.getBean("person");

        System.out.println(persion1);
        System.out.println(persion2);
    }
 }

<!--Bean的作用范围=====================================-->
    <bean id="person" class="com.imooc.ioc.demo3.Person" scope="prototype"/>

Bean's life cycle

public class Man implements BeanNameAware,ApplicationContextAware,InitializingBean,DisposableBean{
    private String name;

    public void setName(String name) {
        System.out.println("第二步：设置属性");
        this.name = name;
    }

    public Man(){
        System.out.println("第一步：初始化...");
    }
    public void setup(){
        System.out.println("第七步：MAN被初始化了...");
    }

    public void teardown(){
        System.out.println("第十一步：MAN被销毁了...");
    }

    @Override
    public void setBeanName(String name) {
        System.out.println("第三步：设置Bean的名称"+name);
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        System.out.println("第四步：了解工厂信息");
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("第六步：属性设置后");
    }

    public void run(){
        System.out.println("第九步：执行业务方法");
    }

    @Override
    public void destroy() throws Exception {
        System.out.println("第十步：执行Spring的销毁方法");
    }
}

* * *
public class MyBeanPostProcessor implements BeanPostProcessor {
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        System.out.println("第五步：初始化前方法...");
    }

    @Override
    public Object postProcessAfterInitialization(final Object bean, String beanName) throws BeansException {
        System.out.println("第八步：初始化后方法...");

    }
}

<bean id="man" class="com.imooc.ioc.demo3.Man" init-method="setup" destroy-method="teardown">
        <property name="name" value="张三"/>
</bean>
<bean class="com.imooc.ioc.demo3.MyBeanPostProcessor"/>

public class SpringDemo3 {
    @Test
    public void demo2(){
       ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        Man man = (Man)applicationContext.getBean("man");

        man.run();

        applicationContext.close();
    }
 }

Enhanced jdk dynamic proxy

public interface UserDao {
    public void findAll();

    public void save();

    public void update();

    public void delete();
}

* * *
public class UserDaoImpl implements  UserDao {
    @Override
    public void findAll() {
        System.out.println("查询用户。。。");
    }

    @Override
    public void save() {
        System.out.println("保存用户。。。");
    }

    @Override
    public void update() {
        System.out.println("修改用户。。。");
    }

    @Override
    public void delete() {
        System.out.println("删除用户。。。");
    }
}

* * *
public class MyBeanPostProcessor implements BeanPostProcessor {
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        //System.out.println("第五步：初始化前方法...");
        return bean;
    }

    @Override
    public Object postProcessAfterInitialization(final Object bean, String beanName) throws BeansException {
        //System.out.println("第八步：初始化后方法...");
        if("userDao".equals(beanName)){
            Object proxy = Proxy.newProxyInstance(bean.getClass().getClassLoader(), bean.getClass().getInterfaces(), new InvocationHandler() {
                @Override
                public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
                    if("save".equals(method.getName())){
                        System.out.println("权限校验===================");
                        return method.invoke(bean,args);
                    }
                    return method.invoke(bean,args);
                }
            });
            return proxy;
        }else{
            return bean;
        }

    }
}

* * *
public class SpringDemo3 {
    @Test
    public void demo3(){
       ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        UserDao userDao = (UserDao)applicationContext.getBean("userDao");

        userDao.findAll();
        userDao.save();
        userDao.update();
        userDao.delete();
    }
 }

<bean class="com.imooc.ioc.demo3.MyBeanPostProcessor"/>

<bean id="userDao" class="com.imooc.ioc.demo3.UserDaoImpl"/>

5.Spring attributes injection (XML way)

Constructor injection properties

Bean attribute value objects by injection constructor or dependence, which guarantees may be used after Bean instance instantiation.
Constructor injection Elements in the declaration of property

public class User {
    private String name;
    private Integer age;

    public User(String name,Integer age){
        this.name = name;
        this.age = age;
    }

    @Override
    public String toString() {
        return "User{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}
 
* * *

public class SpringDemo4 {
    @Test
    public void demo1(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        User user = (User)applicationContext.getBean("user");
        System.out.println(user);
    }
  }

<!--Bean的构造方法的属性注入=============================-->
 <bean id="user" class="com.imooc.ioc.demo4.User">
    <constructor-arg name="name" value="张三" />
    <constructor-arg name="age" value="23"/>
 </bean>

Property setter method injection

public class Person {
    private String name;
    private Integer age;

    private Cat cat;

    public String getName() {
        return name;
    }

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

    public Integer getAge() {
        return age;
    }

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

    public Cat getCat() {
        return cat;
    }

    public void setCat(Cat cat) {
        this.cat = cat;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", cat=" + cat +
                '}';
    }
}

* * *
public class Cat {
    private String name;

    public String getName() {
        return name;
    }

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

    @Override
    public String toString() {
        return "Cat{" +
                "name='" + name + '\'' +
                '}';
    }
}

* * *
public class SpringDemo4 {
    @Test
    public void demo2(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        Person person = (Person)applicationContext.getBean("person");
        System.out.println(person);
    }
 }

<!--Bean的set方法的属性注入==============================-->
 <bean id="person" class="com.imooc.ioc.demo4.Person">
        <property name="name" value="李四"/>
        <property name="age" value="32"/>
        <property name="cat" ref="cat"/>
  </bean>

    <bean id="cat" class="com.imooc.ioc.demo4.Cat">
        <property name="name" value="ketty"/>
    </bean>

Injecting property P namespace

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:p="http://www.springframework.org/schema/p"
       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的p名称空间的属性注入==============================-->
    <bean id="person" class="com.imooc.ioc.demo4.Person" p:name="大黄" p:age="34" p:cat-ref="cat"/>

    <bean id="cat" class="com.imooc.ioc.demo4.Cat" p:name="小黄"/>
       
</beans>

SpEL: spring expression language to simplify dependency injection

- 语法：#{表达式}
  <bean id="" value="#{表达式}">
- SpEL表达式语言

语法：#{}
#{‘hello’} ：使用字符串
#{topicId3}： 使用另一个bean
#{topicId4.content.toUpperCase()}:使用指定名属性，并使用方法.
#{T(java.lang.Math).PI}： 使用静态字段或方法

/**
商品类
*/
public class Product {
    private String name;
    private Double price;

    private Category category;

    public String getName() {
        return name;
    }

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

    public Double getPrice() {
        return price;
    }

    public void setPrice(Double price) {
        this.price = price;
    }

    public Category getCategory() {
        return category;
    }

    public void setCategory(Category category) {
        this.category = category;
    }

    @Override
    public String toString() {
        return "Product{" +
                "name='" + name + '\'' +
                ", price=" + price +
                ", category=" + category +
                '}';
    }
}

* * *
/**
商品分类
*/
public class Category {
    private String name;

    public String getName() {
        return name;
    }

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

    @Override
    public String toString() {
        return "Category{" +
                "name='" + name + '\'' +
                '}';
    }
}

* * *
public class ProductInfo {

    public Double calculatePrice(){
        return Math.random() * 199;
    }
}

* * *
public class SpringDemo4 {
    @Test
    public void demo3(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        Product product = (Product)applicationContext.getBean("product");
        System.out.println(product);
    }
 }

<!--Bean的SpEL的属性注入==============================-->
    <bean id="category" class="com.imooc.ioc.demo4.Category">
        <property name="name" value="#{'服装'}"/>
    </bean>

    <bean id="productInfo" class="com.imooc.ioc.demo4.ProductInfo"/>

    <bean id="product" class="com.imooc.ioc.demo4.Product">
        <property name="name" value="#{'男装'}"/>
        <property name="price" value="#{productInfo.calculatePrice()}"/>
        <property name="category" value="#{category}"/>
    </bean>

Complex type injection

Attribute array type injection
List of attributes set type injection
Set collection type field injection
Map collection type field injection
Properties Properties injection type

public class CollectionBean {
    private String[] arrs; // 数组类型

    private List<String> list;// List集合类型

    private Set<String> set; // Set集合类型

    private Map<String,Integer> map;// Map集合类型

    private Properties properties; // 属性类型

    public String[] getArrs() {
        return arrs;
    }

    public void setArrs(String[] arrs) {
        this.arrs = arrs;
    }

    public List<String> getList() {
        return list;
    }

    public void setList(List<String> list) {
        this.list = list;
    }

    public Set<String> getSet() {
        return set;
    }

    public void setSet(Set<String> set) {
        this.set = set;
    }

    public Map<String, Integer> getMap() {
        return map;
    }

    public void setMap(Map<String, Integer> map) {
        this.map = map;
    }

    public Properties getProperties() {
        return properties;
    }

    public void setProperties(Properties properties) {
        this.properties = properties;
    }

    @Override
    public String toString() {
        return "CollectionBean{" +
                "arrs=" + Arrays.toString(arrs) +
                ", list=" + list +
                ", set=" + set +
                ", map=" + map +
                ", properties=" + properties +
                '}';
    }
}

* * *
public class SpringDemo5 {
    @Test
    public void demo1(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

       CollectionBean collectionBean = (CollectionBean)applicationContext.getBean("collectionBean");

       System.out.println(collectionBean);
    }
}

<!--集合类型的属性注入=================================-->
    <bean id="collectionBean" class="com.imooc.ioc.demo5.CollectionBean">
        <!--数组类型-->
        <property name="arrs">
            <list>
                <value>aaa</value>
                <value>bbb</value>
                <value>ccc</value>
            </list>
        </property>
        <!--List集合的属性注入-->
        <property name="list">
            <list>
                <value>111</value>
                <value>222</value>
                <value>333</value>
            </list>
        </property>
        <!--Set集合的属性注入-->
        <property name="set">
            <set>
                <value>ddd</value>
                <value>eee</value>
                <value>fff</value>
            </set>
        </property>
        <!--Map集合的属性注入-->
        <property name="map">
            <map>
                <entry key="aaa" value="111"/>
                <entry key="bbb" value="222"/>
                <entry key="ccc" value="333"/>
            </map>
        </property>
        <!--Properties的属性注入-->
        <property name="properties">
            <props>
                <prop key="username">root</prop>
                <prop key="password">1234</prop>
            </props>
        </property>
    </bean>

5.Spring of bean-managed (annotation mode)

1. Use annotation defines Bean

@Repository DAO implementation for tagging

@Service used to annotate Service implementation class

@Controller Controller implementation class for tagging

6.Spring attributes injection (annotation mode)

<dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-aop</artifactId>
      <version>4.2.4.RELEASE</version>
 </dependency>
 
 JAR依赖

/**
 * Spring的Bean管理的注解方式：
 *  * 传统方式需要去XML中配置<bean id="" class=""></bean>
 */
@Service("userService")
public class UserService {
    @Value("米饭")
    private String something;
    
    @Resource(name="userDao")
    private UserDao userDao;

    public String sayHello(String name){
        return "Hello" + name;
    }

    public void eat(){
        System.out.println("eat:"+something);
    }

    public void save(){
        System.out.println("Service中保存用户...");
        userDao.save();
    }
}

* * *
@Repository("userDao")
public class UserDao {

    public void save(){
        System.out.println("DAO中保存用户...");
    }
}

* * *
public class SpringDemo1 {
    @Test
    public void demo1(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

        UserService userService = (UserService) applicationContext.getBean("userService");

        String s = userService.sayHello("张三");

        System.out.println(s);
    }

    @Test
    public void demo2(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

        UserService userService = (UserService) applicationContext.getBean("userService");

        userService.eat();
    }

    @Test
    public void demo3(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

        UserService userService = (UserService) applicationContext.getBean("userService");

        userService.save();
    }
}

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

    <!--开启注解扫描=======================-->
<context:component-scan base-package="com.imooc"/>
</beans>

7. Other notes

@Component("bean1")
public class Bean1 {

    @PostConstruct
    public void init(){
        System.out.println("initBean...");
    }

    public void say(){
        System.out.println("say...");
    }

    @PreDestroy
    public void destory(){
        System.out.println("destoryBean...");
    }
}

* * *
@Component("bean2")
@Scope("prototype") //来指定是否单例或者多例
public class Bean2 {

}

* * *
public class SpringDemo2 {
    @Test
    public void demo1(){
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

        Bean1 bean1 = (Bean1)applicationContext.getBean("bean1");

        bean1.say();

        applicationContext.close();
    }

    @Test
    public void demo2(){
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

        Bean2 bean1 = (Bean2)applicationContext.getBean("bean2");
        Bean2 bean2 = (Bean2)applicationContext.getBean("bean2");

        System.out.println(bean1 == bean2);

    }
}

8, xml and comments on integrated development

/*
商品业务层的类
*/
public class ProductService {
    @Resource(name="categoryDao")
    private CategoryDao categoryDao;

    @Resource(name="productDao")
    private ProductDao productDao;

/*    public void setCategoryDao(CategoryDao categoryDao) {
        this.categoryDao = categoryDao;
    }

    public void setProductDao(ProductDao productDao) {
        this.productDao = productDao;
    }*/

    public void save(){
        System.out.println("ProductService的save方法执行了...");
        categoryDao.save();
        productDao.save();
    }
}

* * *
public class CategoryDao {
    public void save(){
        System.out.println("CategoryDao中的save方法执行了...");
    }
}

* * *
public class ProductDao {
    public void save(){
        System.out.println("ProductDao的save方法执行了...");
    }
}

* * *
public class SpringDemo3 {
    @Test
    public void demo1(){
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");

        ProductService productService = (ProductService)applicationContext.getBean("productService");

        productService.save();
    }
}

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

    <!--开启注解扫描=======================-->
<!--    <context:component-scan base-package="com.imooc"/>-->

    <context:annotation-config/>

    <bean id="productService" class="com.imooc.demo3.ProductService">
       <!-- <property name="productDao" ref="productDao"/>
        <property name="categoryDao" ref="categoryDao"/>-->
    </bean>

    <bean id="productDao" class="com.imooc.demo3.ProductDao"/>

    <bean id="categoryDao" class="com.imooc.demo3.CategoryDao"/>
</beans>