2-Spring Bean管理

约定不等于承诺〃 2021-12-04 07:09 239阅读 0赞

*  Spring Bean管理

### Spring Bean管理 ###

**Spring的工厂类**  
![1665530-20190629065614002-302644543.png][]

#### 1.spring的工厂类管理 ####

### direct log messages to stdout ###
    log4j.appender.stdout=org.apache.log4j.ConsoleAppender
    log4j.appender.stdout.Target=System.err
    log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
    log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n
    
    ### direct messages to file mylog.log ###
    log4j.appender.file=org.apache.log4j.FileAppender
    log4j.appender.file.File=c\:mylog.log
    log4j.appender.file.layout=org.apache.log4j.PatternLayout
    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的Bean管理(XML方式) ####

##### 1.使用类构造器实例化(默认无参数) #####

/** * 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"); } } * * *  <bean id="bean1" class="com.imooc.ioc.demo2.Bean1"/>

##### 2.使用静态工厂方法实例化(简单工厂模式) #####

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"); } } * * *  <bean id="bean2" class="com.imooc.ioc.demo2.Bean2Factory" factory-method="createBean2"/>

##### 3.使用实例工厂方法实例化(工厂方法模式) #####

/** * 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的常用配置 ####

##### id和name #####

> 一般情况下，装配一个bean时,通过指定一个id属性作为Bean的名称,id属性在IOC容器中必须是唯一的。

> 如果Bean的名称中含有特殊字符,那么就需要name属性

##### class #####

> class用于设置一个类的完全路径名称，主要作用是IOC容器生成类的实例。

##### Bean的作用域 #####

> **1.singleton**:在SpringIOC容器中仅仅存在一个Bean实例,Bean以单例实例的方式存在。

> **2.prototype**:每次调用getBean()时都会返回一个新的实例

> **3.request**: 每次HTTP请求都会创建一个新的Bean,该作用域仅仅适用于WebApplicationContext环境。

> **4.session** :同一个HTTP Session共享一个Bean，不同的Http Session使用不同的Bean.该作用域仅仅适用于WebAppliacationContext环境。

##### Bean的作用范围测试 #####

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 id="person" class="com.imooc.ioc.demo3.Person" scope="prototype"/>

##### Bean的生命周期 #####

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..."); } }

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

##### 增强jdk的动态代理 #####

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(); } }

#### 5.Spring的属性注入(XML方式) ####

##### 构造方法属性注入 #####

*  通过构造方法注入Bean 的属性值或依赖的对象，它保证了 Bean 实例在实例化后就可以使用.
 *  构造器注入在 元素里声明的属性

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 id="user" class="com.imooc.ioc.demo4.User">
        <constructor-arg name="name" value="张三" />
        <constructor-arg name="age" value="23"/>
     </bean>

##### 属性setter方法注入 #####

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 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>

##### P名称空间的属性注入 #####

<?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 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对依赖注入进行简化 #####

- 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 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>

##### 复杂类型的属性注入 #####

*  数组类型的属性注入
 *  List集合类型的属性注入
 *  Set集合类型的属性注入
 *  Map集合类型的属性注入
 *  Properties类型的属性注入

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); } }

<bean id="collectionBean" class="com.imooc.ioc.demo5.CollectionBean">
            
            <property name="arrs">
                <list>
                    <value>aaa</value>
                    <value>bbb</value>
                    <value>ccc</value>
                </list>
            </property>
            
            <property name="list">
                <list>
                    <value>111</value>
                    <value>222</value>
                    <value>333</value>
                </list>
            </property>
            
            <property name="set">
                <set>
                    <value>ddd</value>
                    <value>eee</value>
                    <value>fff</value>
                </set>
            </property>
            
            <property name="map">
                <map>
                    <entry key="aaa" value="111"/>
                    <entry key="bbb" value="222"/>
                    <entry key="ccc" value="333"/>
                </map>
            </property>
            
            <property name="properties">
                <props>
                    <prop key="username">root</prop>
                    <prop key="password">1234</prop>
                </props>
            </property>
        </bean>

#### 5.Spring的bean管理(注解方式) ####

##### 1.使用注解定义Bean #####

**@Repository 用于对DAO实现类进行标注**

**@Service 用于对Service实现类进行标注**

**@Controller 用于对Controller实现类进行标注**

#### 6.Spring的属性注入(注解方式) ####

<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(); } }

#### 7.其他注解 ####

@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、关于xml和注解整合开发 ####

/* 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">
    
        
    
    
        <context:annotation-config/>
    
        <bean id="productService" class="com.imooc.demo3.ProductService">
           
        </bean>
    
        <bean id="productDao" class="com.imooc.demo3.ProductDao"/>
    
        <bean id="categoryDao" class="com.imooc.demo3.CategoryDao"/>
    </beans>

转载于:https://www.cnblogs.com/Guard9/p/11105497.html

[1665530-20190629065614002-302644543.png]: /images/20211204/7d4ee6e096f54ebf94b513fb8e1dfa1c.png