Spring 4.x (一)
1 Spring是什么?
- Spring是一个开源框架
- Spring是为简化企业级应用开发而生的,使用Spring可以使得简单的JavaBean能够实现以前只有EJB才能实现的功能。
- Spring是一个IOC(DI)和AOP的容器。
- Spring的特点:
- 轻量级:Spring是非侵入性的。基于Spring开发的应用中对象可以不依赖Spring的API。
- 依赖注入
- 面向切面编程
- 容器:Spring是一个容器,因为它包含并且管理应用搞对象的生命周期。
- 框架:Spring实现了使用简单的组件配置组合成一个复杂的应用在Spring中可以使用xml和java朱姐组合这些对象。
- 一站式:在IOC和AOP的基础上可以整合各种企业应用的开源框架和优秀的第三方类库(Spring自身也提供了展现层的Spring MVC 和持久层的Spring JDBC)。
2 Spring的模块
3 传统的HelloWorld VS Spring的HelloWorld
- 传统式HelloWorld
- HelloWorld.java
package com.xuweiwei; public class HelloWorld { private String name; public void setName(String name) { this.name = name; } public void hello(){ System.out.println("你好:"+name); } }
- HelloWorldTest.java
@Test public void testHello(){ HelloWorld helloWorld = new HelloWorld(); helloWorld.setName("许威威"); helloWorld.hello(); }
- Spring式的HelloWorld
- HelloWorld.java
package com.xuweiwei; public class HelloWorld { private String name; public void setName(String name) { this.name = name; } public void hello(){ System.out.println("你好:"+name); } }
- 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" 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-4.3.xsd"> <bean id="helloWorld" class="com.xuweiwei.HelloWorld"> <property name="name" value="许威威"/> </bean> </beans>
- HelloWorldTest.java
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); HelloWorld helloWorld = (HelloWorld) context.getBean("helloWorld"); helloWorld.hello(); }
4 IOC和DI
- IOC:控制反转,反转资源获取的方向。其实,就是将创建对象的方式交给Spring。
- class A{} class B{ private A a; public void setA(A a){ this.a = a; } }
- 传统方式:组件向容器发送请求查找资源,作为回应,容器将返回资源。
A a = new A(); B b = new B(); b.setA(a);
- IOC方式:容器主动的将资源推送给它所管理的组件,组件所需要做的仅仅是选择一种合适的方式接受资源。
B b = (B)applicationContext.getBean("b");
- DI:依赖注入,组件以一些预先定义好的方式接受来自容器的资源注入。比如setter方法或构造方法等。
5 Spring容器
- 在Spring的IOC容器读取Bean配置创建Bean实例之前,必须对它进行实例化。只有在容器实例化之后,才可以从IOC容器中获取Bean实例使用。
- Spring提供了两种类型的IOC容器
- BeanFactory:IOC容器的基本实现。
- ApplicationContext:提供更多的高级特性,是BeanFactory的子类。
5.1 ApplicationContext
- ApplicationContext的两个主要实现类如下:
- FileSystemXmlApplicationContext:从文件系统中加载配置文件
- ClassPathXmlApplicationContext:从类路径下加载配置文件。
- ApplicationContext在初始化的上下文的时候就创建所有的单例Bean。
- WebApplicationContext是专门为WEB应用而准备的,它允许从相对于WEB根目录的路径中完成初始化。
6 配置Bean---基于XML方式
- 在xml文件中通过bean节点来配置bean
<bean id="helloWorld" class="com.xuweiwei.HelloWorld"> <property name="name" value="许威威"/> </bean>
- 在IOC容器中,id必须是唯一的,如果没有指定id,那么Spring容器会自动的将类名首字母小写作为Bean的id值。
- 依赖注入的方式:
- 属性注入
package com.xuweiwei; public class HelloWorld { private String name; public void setName(String name) { this.name = name; } public void hello(){ System.out.println("你好:"+name); } }
<?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-4.3.xsd"> <bean id="helloWorld" class="com.xuweiwei.HelloWorld"> <property name="name" value="许威威"/> </bean> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); HelloWorld helloWorld = (HelloWorld) context.getBean("helloWorld"); helloWorld.hello(); }
- 构造方法注入
package com.xuweiwei; public class HelloWorld { private String name; public HelloWorld(){ } public HelloWorld(String name){ this.name = name; } public void setName(String name) { this.name = name; } public void hello(){ System.out.println("你好:"+name); } }
<?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-4.3.xsd"> <bean id="helloWorld" class="com.xuweiwei.HelloWorld"> <constructor-arg index="0" value="许威威" type="java.lang.String"/> </bean> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); HelloWorld helloWorld = (HelloWorld) context.getBean("helloWorld"); helloWorld.hello(); }
- 工厂方法注入,很少使用
package com.xuweiwei; public class HelloWorld { private String name; public HelloWorld(){ } public HelloWorld(String name){ this.name = name; } public void setName(String name) { this.name = name; } public void hello(){ System.out.println("你好:"+name); } }
package com.xuweiwei; public class HelloWorldFactory { public static HelloWorld getInstance(){ HelloWorld helloWorld = new HelloWorld(); helloWorld.setName("许威威"); return helloWorld; } }
<?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-4.3.xsd"> <bean id="helloWorld" factory-method="getInstance" class="com.xuweiwei.HelloWorldFactory" ></bean> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); HelloWorld helloWorld = (HelloWorld) context.getBean("helloWorld"); helloWorld.hello(); }
- 实例工厂(很少使用)
package com.xuweiwei; public class HelloWorld { private String name; public HelloWorld(){ } public HelloWorld(String name){ this.name = name; } public void setName(String name) { this.name = name; } public void hello(){ System.out.println("你好:"+name); } }
package com.xuweiwei; public class HelloWorldNewInstanceFactory { public HelloWorld helloWorld(){ HelloWorld helloWorld = new HelloWorld(); helloWorld.setName("许威威"); return helloWorld; } }
<?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-4.3.xsd"> <bean id="helloWorldNewInstanceFactory" class="com.xuweiwei.HelloWorldNewInstanceFactory"></bean> <bean id="helloWorld" factory-bean="helloWorldNewInstanceFactory" factory-method="helloWorld"></bean> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); HelloWorld helloWorld = (HelloWorld) context.getBean("helloWorld"); helloWorld.hello(); }
- 属性注入的示例:
- 引用类型的注入:比如主人和猫
package com.xuweiwei; //猫 public class Cat { private String name; public String getName() { return name; } public void setName(String name) { this.name = name; } }
package com.xuweiwei; //主人 public class Master { private String name; private Cat cat ; public String getName() { return name; } public void setName(String name) { this.name = name; } public Cat getCat() { return cat; } public void setCat(Cat cat) { this.cat = cat; } }
<?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-4.3.xsd"> <!-- 创建猫的bean --> <bean id="cat" class="com.xuweiwei.Cat"> <property name="name" value="helloKetty"/> </bean> <!-- 创建主人的bean --> <bean id="master" class="com.xuweiwei.Master"> <property name="name" value="许威威"/> <property name="cat" ref="cat"/> </bean> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); Master master = (Master) context.getBean("master"); System.out.println("猫的名称是:"+master.getCat().getName()); System.out.println("猫的主人的名称是:"+master.getName()); }
- 其它类型的注入:比如数组,Map等
package com.xuweiwei; import java.util.*; public class Person { private Integer id; private String name; private Integer[] nums; private List<String> list; private Set<String> set; private Map<String,Integer> map; private Properties properties; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer[] getNums() { return nums; } public void setNums(Integer[] nums) { this.nums = nums; } 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 "Person{" + "id=" + id + ", name='" + name + '\'' + ", nums=" + Arrays.toString(nums) + ", list=" + list + ", set=" + set + ", map=" + map + ", properties=" + properties + '}'; } }
<?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-4.3.xsd"> <bean id="person" class="com.xuweiwei.Person"> <property name="id" value="1"/> <property name="name"> <value>许威威</value> </property> <property name="nums"> <array> <value>1</value> <value>2</value> <value>3</value> </array> </property> <property name="list"> <list> <value>哈哈</value> <value>呵呵</value> </list> </property> <property name="set"> <set> <value>嘻嘻</value> <value>笨笨</value> </set> </property> <property name="map"> <map > <entry key="许威威" value="1"></entry> <entry key="王伟" value="2"></entry> </map> </property> <property name="properties"> <props > <prop key="helloWorld">你好世界</prop> <prop key="what">什么鬼?</prop> </props> </property> </bean> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); Person person = (Person) context.getBean("person"); System.out.println(person); }
7 Bean的配置---基于注解
- 使用注解自动注入(DI)
package com.xuweiwei; //猫 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 + '\'' + '}'; } }
package com.xuweiwei; import javax.annotation.Resource; //主人 public class Master { private String name; @Resource(name = "cat") private Cat cat ; public String getName() { return name; } public void setName(String name) { this.name = name; } public Cat getCat() { return cat; } public void setCat(Cat cat) { this.cat = cat; } @Override public String toString() { return "Master{" + "name='" + name + '\'' + ", cat=" + cat + '}'; } }
<?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-4.3.xsd"> <!-- 配置注解 --> <context:annotation-config></context:annotation-config> <bean id="cat" class="com.xuweiwei.Cat"> <property name="name" value="helloketty"></property> </bean> <bean id="master" class="com.xuweiwei.Master"> <property name="name" value="许威威"/> </bean> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); Master master = (Master) context.getBean("master"); System.out.println(master); }
- 【注意】:@Resource是用来注入Bean,并且是根据bean的名称
- 使用@AutoWired和@Qualifier注解进行注入
package com.xuweiwei; import org.springframework.beans.factory.annotation.Qualifier; import javax.annotation.Resource; //猫 public class Cat { private String name; public String getName() { return name; } @Qualifier("hello ketty") public void setName(String name) { this.name = name; } @Override public String toString() { return "Cat{" + "name='" + name + '\'' + '}'; } }
package com.xuweiwei; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import javax.annotation.Resource; //主人 public class Master { private String name; @Autowired @Qualifier("cat") private Cat cat ; public String getName() { return name; } public void setName(String name) { this.name = name; } public Cat getCat() { return cat; } public void setCat(Cat cat) { this.cat = cat; } @Override public String toString() { return "Master{" + "name='" + name + '\'' + ", cat=" + cat + '}'; } }
<?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-4.3.xsd"> <!-- 配置注解 --> <context:annotation-config></context:annotation-config> <bean id="cat" class="com.xuweiwei.Cat"> <property name="name" value="helloketty"/> </bean> <bean id="master" class="com.xuweiwei.Master"> <property name="name" value="许威威"/> </bean> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); Master master = (Master) context.getBean("master"); System.out.println(master); }
- 使用注解进行IOC和DI
package com.xuweiwei; import org.springframework.stereotype.Component; //猫 @Component("cat") public class Cat { private String name ="hello ketty"; @Override public String toString() { return "Cat{" + "name='" + name + '\'' + '}'; } }
package com.xuweiwei; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.stereotype.Component; //主人 @Component("master") public class Master { private String name = "许威威"; @Autowired @Qualifier("cat") private Cat cat ; public Cat getCat() { return cat; } public void setCat(Cat cat) { this.cat = cat; } @Override public String toString() { return "Master{" + "name='" + name + '\'' + ", cat=" + cat + '}'; } }
<?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-4.3.xsd"> <!-- 此注解会自动扫描包下的所有类,并为@Component注解的类自动创建对象 --> <context:component-scan base-package="com.xuweiwei"/> </beans>
@Test public void testSpring(){ //启动Spring容器 ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); Master master = (Master) context.getBean("master"); System.out.println(master); }
8 软件三层开发--基于XML
- 实体类:Person.java
package com.xuweiwei.vo; public class Person { private Integer id; private String name; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
- DAO层:
- PersonDAO.java
package com.xuweiwei.dao; import com.xuweiwei.vo.Person; public interface PersonDAO { public void insertPersonInfo(Person person); }
- PersonDAOImpl.java
package com.xuweiwei.dao.impl; import com.xuweiwei.dao.PersonDAO; import com.xuweiwei.vo.Person; public class PersonDAOImpl implements PersonDAO { @Override public void insertPersonInfo(Person person) { System.out.println("保存个人信息"); } }
- Service层
- PersonService
package com.xuweiwei.service; import com.xuweiwei.vo.Person; public interface PersonService { public void savePersonInfo(Person person); }
- PersonServiceImpl
package com.xuweiwei.service.impl; import com.xuweiwei.dao.PersonDAO; import com.xuweiwei.service.PersonService; import com.xuweiwei.vo.Person; public class PersonServiceImpl implements PersonService { private PersonDAO personDAO; public PersonDAO getPersonDAO() { return personDAO; } public void setPersonDAO(PersonDAO personDAO) { this.personDAO = personDAO; } @Override public void savePersonInfo(Person person) { personDAO.insertPersonInfo(person); } }
- action层:PersonAction
package com.xuweiwei.action; import com.xuweiwei.service.PersonService; import com.xuweiwei.vo.Person; public class PersonAction { private PersonService personService; public PersonService getPersonService() { return personService; } public void setPersonService(PersonService personService) { this.personService = personService; } public void add(){ Person p = new Person(); personService.savePersonInfo(p); } }
- 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" 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-4.3.xsd"> <bean id="personDAO" class="com.xuweiwei.dao.impl.PersonDAOImpl"></bean> <bean id="personService" class="com.xuweiwei.service.impl.PersonServiceImpl"> <property name="personDAO" ref="personDAO"/> </bean> <bean id="personAction" class="com.xuweiwei.action.PersonAction"> <property name="personService" ref="personService"/> </bean> </beans>
- 测试
package com.xuweiwei.test; import com.xuweiwei.action.PersonAction; import org.junit.Test; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; public class TestSave { @Test public void test(){ ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); PersonAction personAction = (PersonAction) context.getBean("personAction"); personAction.add(); } }
9 软件三层开发---基于注解
- 实体类:Person.java
package com.xuweiwei.vo; public class Person { private Integer id; private String name; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
- DAO层
- PersonDAO
package com.xuweiwei.dao; import com.xuweiwei.vo.Person; public interface PersonDAO { public void insertPersonInfo(Person person); }
- PersonDAOImpl
package com.xuweiwei.dao.impl; import com.xuweiwei.dao.PersonDAO; import com.xuweiwei.vo.Person; import org.springframework.stereotype.Repository; @Repository("personDAO") public class PersonDAOImpl implements PersonDAO { @Override public void insertPersonInfo(Person person) { System.out.println("保存个人信息"); } }
- Service层
- PersonService
package com.xuweiwei.service; import com.xuweiwei.vo.Person; public interface PersonService { public void savePersonInfo(Person person); }
- PersonServiceImpl
package com.xuweiwei.service.impl; import com.xuweiwei.dao.PersonDAO; import com.xuweiwei.service.PersonService; import com.xuweiwei.vo.Person; import org.springframework.stereotype.Service; import javax.annotation.Resource; @Service("personService") public class PersonServiceImpl implements PersonService { @Resource(name = "personDAO") private PersonDAO personDAO; @Override public void savePersonInfo(Person person) { personDAO.insertPersonInfo(person); } }
- action层:PersonAction
package com.xuweiwei.action; import com.xuweiwei.service.PersonService; import com.xuweiwei.vo.Person; import org.springframework.stereotype.Controller; import javax.annotation.Resource; @Controller("personAction") public class PersonAction { @Resource(name="personService") private PersonService personService; public void add(){ Person p = new Person(); personService.savePersonInfo(p); } }
- 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" 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-4.3.xsd"> <context:component-scan base-package="com.xuweiwei"/> </beans>
- 测试
@Test public void test(){ ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml"); PersonAction personAction = (PersonAction) context.getBean("personAction"); personAction.add(); }
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