Spring 容器

在Spring IOC容器读取Bean配置创建Bean实例之前必须对它进行实例化，只有在容器实例化后才可以从IOC容器里获取Bean实例并使用。

Spring提供了两种类型的IOC容器实现：

1、BeanFactory:IOC容器的基本实现。

2、ApplicationContext:提供了更多的高级特性，是BeanFactory的子接口。

Spring 注入方式：

1.属性注入（setter方法注入）               ---> Helloworld.java

2.构造器注入（<construct-arg>方法注入）-> Car.java

注入属性的细节：通过标志value的type来区别重载

字面值：可用字符串表示的值，可以通过<value>元素标签火value属性进行注入。

如果字面值中包含这特殊字符，可以使用<![CDATA[]]>把字面值包裹起来。

引用其他的Bean:                             --->Person.java

1.在Bean配置文件中，可以通过<ref>元素或ref属性为Bean的属性或构造器参数指定对Bean的引用。

2.也可以在属性 或 构造器里面包含Bean的声明，称为内部Bean.          --person2  

[注意构造器里面的话，要加上无参构造函数和有参构造函数，之后xml文件里面的是<construct-arg>来配置]

级联属性：注意属性需要先初始化后才可以为级联属性赋值               --person3

集合属性：为list配置                                                                 --person5    --->newPersonList

               为map配置                                                               --person6    --->newPersonMap

               为properties配置                                                       --person7    --->dataSource

使用util设置单例的集合bean:

<util:list id="cars">
    <ref bean="car"/>
    <ref bean="car"/>
</util:list>

这样这个集合就可以被其他的bean所共享。

代码：

1.主要的xml文件：

<?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:c="http://www.springframework.org/schema/c"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">

     <bean id="helloworld" class="HelloWorld">
         <property name="name" value="Spring"></property>
     </bean>

    <bean id="helloworld2" class="HelloWorld">
        <property name="name" value="Spring"></property>
    </bean>

    <!--通过构造方法来配置bean的属性-->
    <bean id="car" class="Car">
        <constructor-arg value="Audi" index="1"></constructor-arg>
        <constructor-arg value="Shanghai" index="0"></constructor-arg>
        <constructor-arg value="300000" type="double"></constructor-arg>
    </bean>

    <bean id="car2" class="Car">
        <constructor-arg value="Ford"></constructor-arg>
        <!--<constructor-arg value="Shanghai"></constructor-arg>-->

        <!--如果字面值有含特殊字符可以使用<![CDATA[]]> 包裹起来  属性值也可以使用value 子节点进行配置-->
        <constructor-arg type="java.lang.String">
            <value><![CDATA[Shanghai-->]]></value>
        </constructor-arg>
        <constructor-arg value="240" type="int"></constructor-arg>
    </bean>

    <bean id="car3" class="Car">
        <constructor-arg value="Baoma"></constructor-arg>
        <constructor-arg value="xiamen"></constructor-arg>
        <constructor-arg type="int">
            <value>266</value>
        </constructor-arg>
    </bean>

    <!--///////////可以使用property的ref 属性建立bean 之间的引用关系-->

    <bean id="person" class="Person">
        <property name="name" value="Tom"></property>
        <property name="age" value="24"></property>
        <property name="car" ref="car2"></property>
    </bean>

    <!--<bean id="person2" class="Person">-->
        <!--<property name="name" value="Tom"></property>-->
        <!--<property name="age" value="24"></property>-->
        <!--<property name="car">-->
            <!--<ref bean="car3"/>-->
        <!--</property>-->
    <!--</bean>-->

    <!--内部bean-->
    <bean id="person2" class="Person">
        <property name="name" value="Tom"></property>
        <property name="age" value="24"></property>
        <property name="car">
            <bean class="Car">
                <constructor-arg value="FordAnn"></constructor-arg>
                <constructor-arg value="changan"></constructor-arg>
                <constructor-arg value="456" type="int"></constructor-arg>
            </bean>
        </property>
    </bean>

    <!--构造器实现内部的bean-->
    <bean id="person3" class="Person">
        <constructor-arg value="Jerry"></constructor-arg>
        <constructor-arg value="25"></constructor-arg>
        <constructor-arg ref="car2"></constructor-arg>
        <!--为级联属性赋值.注意属性需要先初始化后才可以为级联属性赋值，否则会报异常-->
         <property name="car.price" value="290000"></property>
    </bean>

    <!-- 测试如何配置List集合属性-->
    <bean id="person5" class="newPersonList">
        <property name="name" value="Mike"></property>
        <property name="age" value="27"></property>
        <property name="cars" >
            <list>
                <ref bean="car"/>
                <ref bean="car2"/>
                <ref bean="car3"/>
            </list>
        </property>
    </bean>
    <!-- 测试如何配置Map集合属性-->
    <bean id="person6" class="newPersonMap">
        <property name="name" value="Rose"></property>
        <property name="age" value="27"></property>
        <property name="cars">
            <map>
                <entry key="AA" value-ref="car"></entry>
                <entry key="BB" value-ref="car2"></entry>
            </map>
        </property>
    </bean>

    <!-- 配置 Properties 属性值-->
    <bean id="dataSource" class="myDataSource">
        <property name="properties">
            <props>
                <prop key="user">root</prop>
                <prop key="password">1234</prop>
                <prop key="jdncurl">jdbc:mysql.jdbc.Driver</prop>
                <prop key="driverClass">com.spring.hello</prop>
            </props>
        </property>
    </bean>

</beans>

2.Car:

public class Car {
    private String brand;
    private String corp;
    private double price;
    private int maxSpeed;

    public Car(String brand,String crop,double price) {
         super();
         this.brand = brand;
         this.corp = crop;
         this.price = price;
    }

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

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

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("Car{");
        sb.append("brand='").append(brand).append('\'');
        sb.append(", corp='").append(corp).append('\'');
        sb.append(", price=").append(price);
        sb.append(", maxSpeed=").append(maxSpeed);
        sb.append('}');
        return sb.toString();
    }
}

3.Person:

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

    private Car car;

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

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

    public Car getCar() {
        return car;
    }

    public void setCar(Car car) {
        this.car = car;
    }

    public Person() {
    }

    public Person(String name, int age, Car car) {
        this.name = name;
        this.age = age;
        this.car = car;
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("Person{");
        sb.append("name='").append(name).append('\'');
        sb.append(", age=").append(age);
        sb.append(", car=").append(car);
        sb.append('}');
        return sb.toString();
    }
}

4.newPersonList:

public class newPersonList {
    private String name;
    private int age;

    private List<Car> cars;

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

    public void setCars(List<Car> cars) {
        this.cars = cars;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

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

    public newPersonList() {
    }

    public newPersonList(String name, int age, List<Car> cars) {
        this.name = name;
        this.age = age;
        this.cars = cars;
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("Person{");
        sb.append("name='").append(name).append('\'');
        sb.append(", age=").append(age);
        sb.append(", cars=").append(cars);
        sb.append('}');
        return sb.toString();
    }
}

5.newPersonMap:

public class newPersonMap {
    private String name;
    private int age;

    private Map<String,Car> cars;

    public newPersonMap(String name, int age, Map<String, Car> cars) {
        this.name = name;
        this.age = age;
        this.cars = cars;
    }

    public newPersonMap() {
    }

    public Map<String, Car> getCars() {
        return cars;
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("newPersonMap{");
        sb.append("name='").append(name).append('\'');
        sb.append(", age=").append(age);
        sb.append(", cars=").append(cars);
        sb.append('}');
        return sb.toString();
    }

    public void setCars(Map<String, Car> cars) {
        this.cars = cars;
    }

    public int getAge() {
        return age;
    }

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

    public String getName() {
        return name;
    }

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

6.myDataSource:

public class myDataSource {
    private Properties properties;

    public Properties getProperties() {
        return properties;
    }

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

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("dataSource{");
        sb.append("properties=").append(properties);
        sb.append('}');
        return sb.toString();
    }
}

7.测试用的main文件：两个

第一个：

public class Main {
    public static void main(String[] arg) {
        //1.创建Spring 的IOC 容器对象
        ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

        //2.从IOC 容器中获取Bean实例
          //利用id定位到IOC容器中的bean
        HelloWorld helloWorld = (HelloWorld) ctx.getBean("helloworld2");
          //利用类型返回IOC容器中的Bean,但要求IOC容器中必须只能有一个该类型的bean
        //HelloWorld helloWorld = ctx.getBean(HelloWorld.class);

        System.out.println(helloWorld);

        Car car = (Car) ctx.getBean("car");
        System.out.println(car);

        car = (Car) ctx.getBean("car2");
        System.out.println(car);

        car = (Car) ctx.getBean("car3");
        System.out.println(car);

        Person person = (Person) ctx.getBean("person");
        System.out.println(person);

        person = (Person) ctx.getBean("person2");
        System.out.println(person);

        person = (Person) ctx.getBean("person3");
        System.out.println(person);

    }

}

第二个：

public class newMain {

        public static void main(String[] arg){
            ApplicationContext ctx = new ClassPathXmlApplicationContext("applicationContext.xml");

            newPersonList person = (newPersonList) ctx.getBean("person5");
            System.out.println(person);

            newPersonMap newPersonMap = (newPersonMap) ctx.getBean("person6");
            System.out.println(newPersonMap);

            myDataSource dataSource = (myDataSource) ctx.getBean("dataSource");
            System.out.println();
            System.out.println(dataSource.getProperties());
        }
}

项目层次：