控制反转（IOC）

public class bean1 {
    private String name;
    private int age;
    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 class student {
    private String name;
    private List<String> listValue;
    private Set<String> setValue;
    private Map mapValue;
    private Properties proValue;
    private bean1 bean1;
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public List<String> getListValue() {
        return listValue;
    }
    public void setListValue(List<String> listValue) {
        this.listValue = listValue;
    }
    public Set<String> getSetValue() {
        return setValue;
    }
    public void setSetValue(Set<String> setValue) {
        this.setValue = setValue;
    }
    public Map getMapValue() {
        return mapValue;
    }
    public void setMapValue(Map mapValue) {
        this.mapValue = mapValue;
    }
    public Properties getProValue() {
        return proValue;
    }
    public void setProValue(Properties proValue) {
        this.proValue = proValue;
    }
    public bean1 getBean1() {
        return bean1;
    }
    public void setBean1(bean1 bean1) {
        this.Bean1 = Bean1;
    }
    @Override
    public String toString() {
        return "test{" +
                "name='" + name + '\'' +
                ", listValue=" + listValue +
                ", setValue=" + setValue +
                ", mapValue=" + mapValue +
                ", proValue=" + proValue +
                '}';
    }
}

spring帮创建对象

id为唯一标识符，外界通过它来沟通，通常和类名保持一致

applicationCotext.xml

<bean id ="student" class="com.spdb.gr.father">
    <property name = "name" value = "郭"><property>
    <property name = "listValue">
         <list>
             <value>list1</value>
             <value>list2</value>
         </list>
    <property>
    <property name = "setValue">
         <set>
             <value>set1</value>
             <value>set2</value>
         </set>
    <property>
    <property name = "mapValue">
         <map>
             <entry key = "key1" value = "value1"></entry>
             <entry key = "key2" >
                 <value>value2</value>
             </entry>
         </map>
    <property>
<--Properties 类的具体使用。以key=value 的 键值对的形式进行存储值。 key值不能重复。-->
    <property name = "propValue">
         <props>
             <prop key = "propKey1">propValue1</prop>
             <prop key = "propKey2">propValue2</prop>
         </props>
    <property>
<--此处做对象的引用-->
    <property name = "bean1" ref= "bean1"><property>
</bean>
<bean id ="bean1" class="com.spdb.gr.bean1">
    <property name = "name" value = "郭"><property>
    <property name = "age" value = "18"><property>
</bean>

注意：先读取，后创建（对象），最后引用（意为如果某一个bean中引用了其他对象，那就在最后一步进行引用（所以不会因为bean1在student之后，导致引用不上！！！））

test（一运行他就能获取applicationCotext.xml文件，加载此文件的时候就会创建bean对象了，可以在构造方法写一个打印语句，可以查看到她显现出来）

public class SingletonDemo {
    public SingletonDemo() {
        System.out.println("进来了");
    }
    public void testSpring(){
        ApplicationCotext context = new ClassPathXmlApplicationContext("applicationCotext.xml");
        //此处为获取bean中的对象，第一个参数为bean中的id，第二个为对象类型
        Student student = context.getBean("student",Student.class);
        System.out.println("student.baen1.age = "+ student.getBean1.getAge());
        System.out.println(student);
    }
}