Spring 教程01

Posted 2020-10-05 c0

spring-1
1.    Xml


<!-- \src\beans-annotation.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-4.0.xsd">

    <!-- 配置自动扫描的包: 需要加入 aop 对应的 jar 包 -->
    <context:component-scan base-package="com.atguigu.spring.annotation.generic"></context:component-scan>

</beans>

<!-- \src\beans-auto.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-4.0.xsd">

    <!-- 自动装配: 只声明 bean, 而把 bean 之间的关系交给 IOC 容器来完成 -->
    <!-- byType: 根据类型进行自动装配. 但要求 IOC 容器中只有一个类型对应的 bean, 若有多个则无法完成自动装配. byName: 
        若属性名和某一个 bean 的 id 名一致, 即可完成自动装配. 若没有 id 一致的, 则无法完成自动装配 -->
    <!-- 在使用 XML 配置时, 自动转配用的不多. 但在基于 注解 的配置时, 自动装配使用的较多. -->
    <bean id="dao" class="com.atguigu.spring.ref.Dao">
        <property name="dataSource" value="C3P0"></property>
    </bean>

    <!-- 默认情况下 bean 是单例的! -->
    <!-- 但有的时候, bean 就不能使单例的. 例如: Struts2 的 Action 就不是单例的! 可以通过 scope 属性来指定 
        bean 的作用域 -->
    <!-- prototype: 原型的. 每次调用 getBean 方法都会返回一个新的 bean. 且在第一次调用 getBean 方法时才创建实例 
        singleton: 单例的. 每次调用 getBean 方法都会返回同一个 bean. 且在 IOC 容器初始化时即创建 bean 的实例. 默认值 -->
    <bean id="dao2" class="com.atguigu.spring.ref.Dao" scope="prototype"></bean>

    <bean id="service" class="com.atguigu.spring.ref.Service"
        autowire="byName"></bean>

    <bean id="action" class="com.atguigu.spring.ref.Action" autowire="byType"></bean>

    <!-- 导入外部的资源文件 -->
    <context:property-placeholder location="classpath:db.properties" />

    <!-- 配置数据源 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="user" value="${jdbc.user}"></property>
        <property name="password" value="${jdbc.password}"></property>
        <property name="driverClass" value="${jdbc.driverClass}"></property>
        <property name="jdbcUrl" value="${jdbc.jdbcUrl}"></property>

        <property name="initialPoolSize" value="${jdbc.initPoolSize}"></property>
        <property name="maxPoolSize" value="${jdbc.maxPoolSize}"></property>
    </bean>

    <!-- 测试 SpEL: 可以为属性进行动态的赋值(了解) -->
    <bean id="girl" class="com.atguigu.spring.helloworld.User">
        <property name="userName" value="周迅"></property>
    </bean>

    <bean id="boy" class="com.atguigu.spring.helloworld.User"
        init-method="init" destroy-method="destroy">
        <property name="userName" value="高胜远"></property>
        <property name="wifeName" value="#{girl.userName}"></property>
    </bean>

    <!-- 配置 bean 后置处理器: 不需要配置 id 属性, IOC 容器会识别到他是一个 bean 后置处理器, 并调用其方法 -->
    <bean class="com.atguigu.spring.ref.MyBeanPostProcessor"></bean>

    <!-- 通过工厂方法的方式来配置 bean -->
    <!-- 1. 通过静态工厂方法: 一个类中有一个静态方法, 可以返回一个类的实例(了解) -->
    <!-- 在 class 中指定静态工厂方法的全类名, 在 factory-method 中指定静态工厂方法的方法名 -->
    <bean id="dateFormat" class="java.text.DateFormat" factory-method="getDateInstance">
        <!-- 可以通过 constructor-arg 子节点为静态工厂方法指定参数 -->
        <constructor-arg value="2"></constructor-arg>
    </bean>

    <!-- 2. 实例工厂方法: 先需要创建工厂对象, 再调用工厂的非静态方法返回实例(了解) -->
    <!-- ①. 创建工厂对应的 bean -->
    <bean id="simpleDateFormat" class="java.text.SimpleDateFormat">
        <constructor-arg value="yyyy-MM-dd hh:mm:ss"></constructor-arg>
    </bean>

    <!-- ②. 有实例工厂方法来创建 bean 实例 -->
    <!-- factory-bean 指向工厂 bean, factory-method 指定工厂方法(了解) -->
    <bean id="datetime" factory-bean="simpleDateFormat"
        factory-method="parse">
        <!-- 通过 constructor-arg 执行调用工厂方法需要传入的参数 -->
        <constructor-arg value="1990-12-12 12:12:12"></constructor-arg>
    </bean>

    <!-- 配置通过 FactroyBean 的方式来创建 bean 的实例(了解) -->
    <bean id="user" class="com.atguigu.spring.ref.UserBean"></bean>

</beans>

<!-- \src\beans.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:util="http://www.springframework.org/schema/util"
    xmlns:p="http://www.springframework.org/schema/p"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.0.xsd">

    <!-- 配置一个 bean -->
    <bean id="helloWorld" class="com.atguigu.spring.helloworld.HelloWorld">
        <!-- 为属性赋值 -->
        <property name="user" value="Jerry"></property>
    </bean>

    <!-- 配置一个 bean -->
    <bean id="helloWorld2" class="com.atguigu.spring.helloworld.HelloWorld">
        <!-- 为属性赋值 -->
        <!-- 通过属性注入: 通过 setter 方法注入属性值 -->
        <property name="user" value="Tom"></property>
    </bean>

    <!-- 通过构造器注入属性值 -->
    <bean id="helloWorld3" class="com.atguigu.spring.helloworld.HelloWorld">
        <!-- 要求: 在 Bean 中必须有对应的构造器. -->
        <constructor-arg value="Mike"></constructor-arg>
    </bean>

    <!-- 若一个 bean 有多个构造器, 如何通过构造器来为 bean 的属性赋值 -->
    <!-- 可以根据 index 和 value 进行更加精确的定位. (了解) -->
    <bean id="car" class="com.atguigu.spring.helloworld.Car">
        <constructor-arg value="KUGA" index="1"></constructor-arg>
        <constructor-arg value="ChangAnFord" index="0"></constructor-arg>
        <constructor-arg value="250000" type="float"></constructor-arg>
    </bean>

    <bean id="car2" class="com.atguigu.spring.helloworld.Car">
        <constructor-arg value="ChangAnMazda"></constructor-arg>
        <!-- 若字面值中包含特殊字符, 则可以使用 DCDATA 来进行赋值. (了解) -->
        <constructor-arg>
            <value><![CDATA[<ATARZA>]]></value>
        </constructor-arg>
        <constructor-arg value="180" type="int"></constructor-arg>
    </bean>

    <!-- 配置 bean -->
    <bean id="dao5" class="com.atguigu.spring.ref.Dao"></bean>

    <bean id="service" class="com.atguigu.spring.ref.Service">
        <!-- 通过 ref 属性值指定当前属性指向哪一个 bean! -->
        <property name="dao" ref="dao5"></property>
    </bean>

    <!-- 声明使用内部 bean -->
    <bean id="service2" class="com.atguigu.spring.ref.Service">
        <property name="dao">
            <!-- 内部 bean, 类似于匿名内部类对象. 不能被外部的 bean 来引用, 也没有必要设置 id 属性 -->
            <bean class="com.atguigu.spring.ref.Dao">
                <property name="dataSource" value="c3p0"></property>
            </bean>
        </property>
    </bean>

    <bean id="action" class="com.atguigu.spring.ref.Action">
        <property name="service" ref="service2"></property>
        <!-- 设置级联属性(了解) -->
        <property name="service.dao.dataSource" value="DBCP2"></property>
    </bean>

    <bean id="dao2" class="com.atguigu.spring.ref.Dao">
        <!-- 为 Dao 的 dataSource 属性赋值为 null, 若某一个 bean 的属性值不是 null, 使用时需要为其设置为 null(了解) -->
        <property name="dataSource">
            <null />
        </property>
    </bean>

    <!-- 装配集合属性 -->
    <bean id="user" class="com.atguigu.spring.helloworld.User">
        <property name="userName" value="Jack"></property>
        <property name="cars">
            <!-- 使用 list 元素来装配集合属性 -->
            <list>
                <ref bean="car" />
                <ref bean="car2" />
            </list>
        </property>
    </bean>

    <!-- 声明集合类型的 bean -->
    <util:list id="cars">
        <ref bean="car" />
        <ref bean="car2" />
    </util:list>

    <bean id="user2" class="com.atguigu.spring.helloworld.User">
        <property name="userName" value="Rose"></property>
        <!-- 引用外部声明的 list -->
        <property name="cars" ref="cars"></property>
    </bean>

    <bean id="user3" class="com.atguigu.spring.helloworld.User"
        p:cars-ref="cars" p:userName="Titannic"></bean>

    <!-- bean 的配置能够继承吗 ? 使用 parent 来完成继承 -->
    <bean id="user4" parent="user" p:userName="Bob"></bean>

    <bean id="user6" parent="user" p:userName="维多利亚"></bean>

    <!-- 测试 depents-on -->
    <bean id="user5" parent="user" p:userName="Backham" depends-on="user6"></bean>

</beans>

2.    Properties

# \src\db.properties
jdbc.user=root
jdbc.password=1230
jdbc.driverClass=com.mysql.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql:///test

jdbc.initPoolSize=5
jdbc.maxPoolSize=10

3.    Java


// \src\com\atguigu\spring\annotation\generic\BaseDao.java
package com.atguigu.spring.annotation.generic;

public class BaseDao<T> {

    public void save(T entity){
        System.out.println("Save:" + entity);
    }
    
}

// \src\com\atguigu\spring\annotation\generic\BaseService.java
package com.atguigu.spring.annotation.generic;

import org.springframework.beans.factory.annotation.Autowired;

public class BaseService<T> {

    @Autowired
    private BaseDao<T> dao;
    
    public void addNew(T entity){
        System.out.println("addNew by " + dao);
        dao.save(entity);
    }
    
}

// \src\com\atguigu\spring\annotation\generic\Main.java
package com.atguigu.spring.annotation.generic;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {
    
    public static void main(String[] args) {
        
        ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");
        
        UserService userService = (UserService) ctx.getBean("userService");
        userService.addNew(new User());
        
        RoleService roleService = (RoleService) ctx.getBean("roleService");
        roleService.addNew(new Role()); 
    }
    
}

// \src\com\atguigu\spring\annotation\generic\Role.java
package com.atguigu.spring.annotation.generic;

public class Role {

}

// \src\com\atguigu\spring\annotation\generic\RoleDao.java
package com.atguigu.spring.annotation.generic;

import org.springframework.stereotype.Repository;

@Repository
public class RoleDao extends BaseDao<Role>{

}

// \src\com\atguigu\spring\annotation\generic\RoleService.java
package com.atguigu.spring.annotation.generic;

import org.springframework.stereotype.Service;

@Service
public class RoleService extends BaseService<Role>{

}

// \src\com\atguigu\spring\annotation\generic\User.java
package com.atguigu.spring.annotation.generic;

public class User {

}

// \src\com\atguigu\spring\annotation\generic\UserDao.java
package com.atguigu.spring.annotation.generic;

import org.springframework.stereotype.Repository;

@Repository
public class UserDao extends BaseDao<User>{

}

// \src\com\atguigu\spring\annotation\generic\UserService.java
package com.atguigu.spring.annotation.generic;

import org.springframework.stereotype.Service;

//若注解没有指定 bean 的 id, 则类名第一个字母小写即为 bean 的 id
@Service
public class UserService extends BaseService<User>{

}

// \src\com\atguigu\spring\annotation\Main.java
package com.atguigu.spring.annotation;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {
    
    public static void main(String[] args) {
        
        ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-annotation.xml");
        
        UserAction userAction = ctx.getBean(UserAction.class);
        userAction.execute();
    }
    
}

// \src\com\atguigu\spring\annotation\UserAction.java
package com.atguigu.spring.annotation;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;

@Controller
public class UserAction {
    
    @Autowired
    private UsreService usreService;
    
    public void execute(){
        System.out.println("接受请求");
        usreService.addNew();
    }
    
}

// \src\com\atguigu\spring\annotation\UserDao.java
package com.atguigu.spring.annotation;

import org.springframework.stereotype.Service;

@Service
public class UserDao {
    
    public void save(){
        System.out.println("保存新用户");
    }
    
}

// \src\com\atguigu\spring\annotation\UsreService.java
package com.atguigu.spring.annotation;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UsreService {
    
    @Autowired
    private UserDao userDao;
    
    public void addNew(){
        System.out.println("添加新用户");
        userDao.save();
    }
    
}

// \src\com\atguigu\spring\helloworld\Car.java
package com.atguigu.spring.helloworld;

public class Car {

    private String company;
    private String brand;

    private int maxSpeed;
    private float price;

    public Car(String company, String brand, float price) {
        super();
        this.company = company;
        this.brand = brand;
        this.price = price;
    }

    public Car(String company, String brand, int maxSpeed) {
        super();
        this.company = company;
        this.brand = brand;
        this.maxSpeed = maxSpeed;
    }

    public Car(String company, String brand, int maxSpeed, float price) {
        super();
        this.company = company;
        this.brand = brand;
        this.maxSpeed = maxSpeed;
        this.price = price;
    }

    @Override
    public String toString() {
        return "Car [company=" + company + ", brand=" + brand + ", maxSpeed="
                + maxSpeed + ", price=" + price + "]";
    }
}

// \src\com\atguigu\spring\helloworld\HelloWorld.java
package com.atguigu.spring.helloworld;

public class HelloWorld {

    private String user;
    
    public HelloWorld() {
        System.out.println("HelloWorld‘s constructor...");
    }
    
    public void setUser(String user) {
        System.out.println("setUser:" + user);
        this.user = user;
    }
    
    public HelloWorld(String user) {
        this.user = user;
    }

    public void hello(){
        System.out.println("Hello: " + user);
    }
    
}

// \src\com\atguigu\spring\helloworld\Main.java
package com.atguigu.spring.helloworld;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Main {
    
    public static void main(String[] args) {
        
//      HelloWorld helloWorld = new HelloWorld();
//      helloWorld.setUser("Tom");
//      helloWorld.hello(); 
        
        //1. 创建 Spring 的 IOC 容器
        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans.xml");
        
        //2. 从 IOC 容器中获取 bean 的实例
        HelloWorld helloWorld = (HelloWorld) ctx.getBean("helloWorld3");
        
        //根据类型来获取 bean 的实例: 要求在  IOC 容器中只有一个与之类型匹配的 bean, 若有多个则会抛出异常. 
        //一般情况下, 该方法可用, 因为一般情况下, 在一个 IOC 容器中一个类型对应的 bean 也只有一个. 
//      HelloWorld helloWorld1 = ctx.getBean(HelloWorld.class);
        
        //3. 使用 bean
        helloWorld.hello();
        
        Car car = (Car) ctx.getBean("car");
        System.out.println(car);
        
        Car car2 = (Car) ctx.getBean("car2");
        System.out.println(car2);
        
        //4. 测试使用集合属性
        User user = (User) ctx.getBean("user5");
        System.out.println(user);
    }
    
}

// \src\com\atguigu\spring\helloworld\User.java
package com.atguigu.spring.helloworld;

import java.util.List;

public class User {

    private String userName;
    private List<Car> cars;
    
    private String wifeName;
    
    public String getWifeName() {
        return wifeName;
    }

    public void setWifeName(String wifeName) {
        System.out.println("setWifhName: " + wifeName);
        this.wifeName = wifeName;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public List<Car> getCars() {
        return cars;
    }

    public void setCars(List<Car> cars) {
        this.cars = cars;
    }
    
    public User() {
        System.out.println("User‘s Construtor...");
    }

    @Override
    public String toString() {
        return "User [userName=" + userName + ", cars=" + cars + "]";
    }
    
    public void init(){
        System.out.println("init method...");
    }
    
    public void destroy(){
        System.out.println("destroy method...");
    }

}

// \src\com\atguigu\spring\ref\Action.java
package com.atguigu.spring.ref;

public class Action {

    private Service service;
    
    public void setService(Service service) {
        this.service = service;
    }
    
    public Service getService() {
        return service;
    }
    
    public void execute(){
        System.out.println("Action‘s execute...");
        service.save();
    }
    
}

// \src\com\atguigu\spring\ref\Dao.java
package com.atguigu.spring.ref;

public class Dao {

    private String dataSource = "dbcp";
    
    public void setDataSource(String dataSource) {
        this.dataSource = dataSource;
    }
    
    public void save(){
        System.out.println("save by " + dataSource);
    }
    
    public Dao() {
        System.out.println("Dao‘s Constructor...");
    }
    
}

// \src\com\atguigu\spring\ref\Main.java
package com.atguigu.spring.ref;

import java.sql.SQLException;
import java.text.DateFormat;
import java.util.Date;

import javax.sql.DataSource;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import com.atguigu.spring.helloworld.User;

public class Main {
    
    public static void main(String[] args) throws SQLException {
        
        ClassPathXmlApplicationContext ctx = new ClassPathXmlApplicationContext("beans-auto.xml");
        Action action = ctx.getBean(Action.class);
        
        action.execute();
        
        //测试 bean 的作用域
        Dao dao1 = (Dao) ctx.getBean("dao2");
        Dao dao2 = (Dao) ctx.getBean("dao2");
        
        System.out.println(dao1 == dao2);
        
        //测试使用外部属性文件
        DataSource dataSource = (DataSource) ctx.getBean("dataSource");
        System.out.println(dataSource.getConnection());
        
        //测试 spEL
        User boy = (User) ctx.getBean("boy");
        System.out.println(boy.getUserName() + ":" + boy.getWifeName());
        
//      DateFormat dateFormat = DateFormat.getDateInstance(DateFormat.FULL);
        DateFormat dateFormat = (DateFormat) ctx.getBean("dateFormat");
        System.out.println(dateFormat.format(new Date()));
        
        Date date = (Date) ctx.getBean("datetime");
        System.out.println(date);
        
        User user = (User) ctx.getBean("user");
        System.out.println(user);
        
        ctx.close();
    }
    
}

// \src\com\atguigu\spring\ref\MyBeanPostProcessor.java
package com.atguigu.spring.ref;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;

import com.atguigu.spring.helloworld.User;

public class MyBeanPostProcessor implements BeanPostProcessor {

    //该方法在 init 方法之后被调用
    @Override
    public Object postProcessAfterInitialization(Object arg0, String arg1)
            throws BeansException {
        if(arg1.equals("boy")){
            System.out.println("postProcessAfterInitialization..." + arg0 + "," + arg1);
            User user = (User) arg0;
            user.setUserName("李大齐");
        }
        return arg0;
    }

    //该方法在 init 方法之前被调用
    //可以工作返回的对象来决定最终返回给 getBean 方法的对象是哪一个, 属性值是什么
    /**
     * @param arg0: 实际要返回的对象
     * @param arg1: bean 的 id 值
     */
    @Override
    public Object postProcessBeforeInitialization(Object arg0, String arg1)
            throws BeansException {
        if(arg1.equals("boy"))
            System.out.println("postProcessBeforeInitialization..." + arg0 + "," + arg1);
        return arg0;
    }

}

// \src\com\atguigu\spring\ref\Service.java
package com.atguigu.spring.ref;

public class Service {

    private Dao dao;
    
    public void setDao(Dao dao) {
        this.dao = dao;
    }
    
    public Dao getDao() {
        return dao;
    }
    
    public void save(){
        System.out.println("Service‘s save");
        dao.save();
    }
    
}

// \src\com\atguigu\spring\ref\UserBean.java
package com.atguigu.spring.ref;

import java.util.ArrayList;
import java.util.List;

import org.springframework.beans.factory.FactoryBean;

import com.atguigu.spring.helloworld.Car;
import com.atguigu.spring.helloworld.User;

public class UserBean implements FactoryBean<User>{

    /**
     * 返回的 bean 的实例
     */
    @Override
    public User getObject() throws Exception {
        User user = new User();
        user.setUserName("abc");
        user.setWifeName("ABC");
        
        List<Car> cars = new ArrayList<>();
        cars.add(new Car("ShangHai", "BuiKe", 180, 300000));
        cars.add(new Car("ShangHai", "CRUZE", 130, 150000));
        
        user.setCars(cars);
        return user;
    }

    /**
     * 返回的 bean 的类型
     */
    @Override
    public Class<?> getObjectType() {
        return User.class;
    }

    /**
     * 返回的 bean 是否为单例的
     */
    @Override
    public boolean isSingleton() {
        return true;
    }

}