spring1-test4-正确为各种属性赋值

实验4-正确为各种属性赋值

1.测试使用null值，ref引用外部的值
2.引用类型赋值（引用其他bean、引用内部bean）
3.集合类型赋值（List、Map、Properties)
4.util名称空间创建集合类型bean，引用一个可以外部引用的集合
5.级联属性赋值

1.测试使用null值，ref引用外部的值：

• ioc2.xml配置文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
        <!--  实验4：正确的为各种属性赋值  -->
        <!--  1.测试使用null值，ref引用外部的值
            2.引用类型赋值（引用其他bean、引用内部bean）
            3.集合类型赋值（List、Map、Properties)
            4.util名称空间创建集合类型bean，引用一个可以外部引用的集合
            5.级联属性赋值  -->
    <bean id="person1" class="Person">
            <!-- 在标签里面进行复杂的赋值 -->
            <!-- 使name=null -->
            <property name="name">
                <null></null>
            </property>
            <!-- ref: 代表引用外面的值 -->
            <property name="car" ref="car01"></property>
    </bean>
    <bean id="car01" class="Car">
        <property name="carName" value="宝马"></property>
        <property name="color" value="绿色"></property>
        <property name="price" value="300000"></property>
    </bean>
</beans>

• Person类:

import java.util.List;
import java.util.Map;
import java.util.Properties;

public class Person {
    //基本类型直接使用<property>标签赋值
    private String name;
    private Integer age;
    private String gender;
    private String email;

    private Car car;

    private List<Book> books;

    private Map<String, Object> maps;

    private Properties properties;

    public Person() {
        System.out.println("调用了无参的构造方法。。。");
    }

    public Car getCar() {
        return car;
    }

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

    public List<Book> getBooks() {
        return books;
    }

    public void setBooks(List<Book> books) {
        this.books = books;
    }

    public Map<String, Object> getMaps() {
        return maps;
    }

    public void setMaps(Map<String, Object> maps) {
        this.maps = maps;
    }

    public Properties getProperties() {
        return properties;
    }

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

    public Person(String name, Integer age, String gender, String email) {
        this.name = name;
        this.age = age;
        this.gender = gender;
        this.email = email;
    }

    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 String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", gender='" + gender + '\'' +
                ", email='" + email + '\'' +
                ", car=" + car +
                ", books=" + books +
                ", maps=" + maps +
                ", properties=" + properties +
                '}';
    }
}

• Car类：

public class Car {
    private String carName;
    private Integer price;
    private String color;

    public String getCarName() {
        return carName;
    }

    public void setCarName(String carName) {
        this.carName = carName;
    }

    public Integer getPrice() {
        return price;
    }

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

    public String getColor() {
        return color;
    }

    public void setColor(String color) {
        this.color = color;
    }

    @Override
    public String toString() {
        return "Car{" +
                "carName='" + carName + '\'' +
                ", price=" + price +
                ", color='" + color + '\'' +
                '}';
    }
}

• Book类：

public class Book {
    private String bookName;
    private String author;

    public String getBookName() {
        return bookName;
    }

    public void setBookName(String bookName) {
        this.bookName = bookName;
    }

    public String getAuthor() {
        return author;
    }

    public void setAuthor(String author) {
        this.author = author;
    }

    @Override
    public String toString() {
        return "Book{" +
                "bookName='" + bookName + '\'' +
                ", author='" + author + '\'' +
                '}';
    }
}

• test:

@Test
public void test07(){
    ApplicationContext ioc = new ClassPathXmlApplicationContext("ioc2.xml");
    //1. 测试使用null值，默认引用类型是null，基本类型是默认值
    Person bean = (Person) ioc.getBean("person1");
    System.out.println(bean);
    System.out.println(bean.getCar());

    Car car = bean.getCar();
    Object car01 = ioc.getBean("car01");
    System.out.println(car==car01);
}

2.引用类型赋值（引用其他bean、引用内部bean）

• 测试类：

@Test
public void test08() {
    ApplicationContext ioc = new ClassPathXmlApplicationContext("ioc2.xml");
    //从ioc容器中获取person，再通过person获取到car值
    Person person1 = (Person) ioc.getBean("person1");
    Car car = person1.getCar();
    System.out.println(car);
}

• 在person内部写一个car。这叫内部bean

<bean id="person1" class="Person">
        <!-- 在标签里面进行复杂的赋值 -->
        <!-- 使name=null -->
        <property name="name"> <null></null> </property>
        <!-- ref: 代表引用外面的值 -->
        <!--<property name="car" ref="car01"></property>-->

        <property name="car">
            <!--对象我们可以使用bean标签创建，car = new Car();引用内部bean-->
            <bean class="Car">
                <property name="carName" value="自行车"></property>
            </bean>
        </property>
</bean>

3.集合类型赋值（List、Map、Properties)

1.List集合

<bean id="book2" class="Book">
    <property name="bookName" value="东游记"></property>
</bean>
<bean id="person2" class="Person">
    <!-- 如何为list属性赋值呢？-->
    <property name="books">
        <!-- 这么写就相当于books = new ArrayList<Book>() -->
        <list>
                <!--list标签中添加每一个元素-->
                <!-- 内部的id="boook000x"并不能被识别，引用内部bean时，不能被获取到
                只能内部使用-->
                <bean id="book000x" class="Book" p:bookName="西游记"></bean>
                <ref bean="book2"></ref>
        </list>
    </property>
</bean>

public void test09() {
    ApplicationContext ioc = new ClassPathXmlApplicationContext("ioc2.xml");
    Person person2 = (Person) ioc.getBean("person2");
    List<Book> books = person2.getBooks();
    System.out.println(books);
}

2.Map集合

@Test
public void test10() {
    ApplicationContext ioc = new ClassPathXmlApplicationContext("ioc2.xml");
    Person person2 = (Person) ioc.getBean("person2");
    Map<String, Object> maps1 = person2.getMaps();
    System.out.println(maps1);
}

<bean id="person2" class="Person">
    <!--给map赋值，maps=new LinkedHashMap<>();-->
    <property name="maps">
        <map>
            <!--一个entry代表一个键值对-->
            <entry key="key01" value="张三"></entry>
            <entry key="key02" value="18"></entry>
            <entry key="key03" value-ref="book2"></entry>
            <entry key="key04" >
                <bean class="Car">
                    <property name="carName" value="benci"></property>
                </bean>
            </entry>
            <entry key="key05" >
                <map></map>
            </entry>
        </map>
    </property>
</bean>

3.Properties属性赋值

@Test
public void test11() {
    ApplicationContext ioc = new ClassPathXmlApplicationContext("ioc2.xml");
    Person person2 = (Person) ioc.getBean("person2");
    Properties person2Properties = person2.getProperties();
    System.out.println(person2Properties);
}

<bean id="person2" class="Person">
    <!-- 为Properties赋值-->
    <property name="properties">
        <!-- properties = new Properties();所有的key和value都是String类型的-->
        <props>
            <prop key="username">root</prop>
            <prop key="password">123</prop>
        </props>
    </property>
</bean>

4.util名称空间创建集合类型bean，方便之后代码中可以引用一个外部的集合

@Test
public void test12() {
    ApplicationContext ioc = new ClassPathXmlApplicationContext("ioc2.xml");
    Person person2 = (Person) ioc.getBean("person03");
    Map<String, Object> maps = person2.getMaps();
    System.out.println(maps);

    Map<String, Object> bean = (Map<String, Object>) ioc.getBean("myMap");
    System.out.println(bean.getClass());
}

<util:map id="myMap">
    <!--只是添加元素-->
    <entry key="key01" value="张三"></entry>
    <entry key="key02" value="18"></entry>
    <entry key="key03" value-ref="book2"></entry>
    <entry key="key04" >
        <bean class="Car">
            <property name="carName" value="benci"></property>
        </bean>
    </entry>
    <entry key="key05" >
        <map></map>
    </entry>
</util:map>

<!--util名称空间创建集合类型的bean，方便别人引用-->
<bean id="person03" class="Person">
    <property name="maps" ref="myMap"></property>
</bean>


<util:list id="myList">
    <list></list>
    <bean class="Person"></bean>
    <value>12</value>
    <ref bean="myMap/>
</util:map>
//这个list里面有4个值，[[],Person对象,12,{}]

5.级联属性赋值

<bean id="car01" class="Car">
    <property name="carName" value="宝马"></property>
    <property name="color" value="绿色"></property>
    <property name="price" value="300000"></property>
</bean>

<!--级联属性：就是属性的属性，就像person对象的car属性-->
<bean id="person04" class="Person">
    <!--为car赋值的时候，顺便改下car的值-->
    <property name="car" ref="car01"></property>
    <property name="car.price" value="900000"></property>
</bean>

@Test
public void test13() {
    ApplicationContext ioc = new ClassPathXmlApplicationContext("ioc2.xml");
    Person person04 = (Person) ioc.getBean("person04");
    Object car01 = ioc.getBean("car01");
    System.out.println("这是容器中的car"+car01);
    System.out.println("这是person中的car"+person04.getCar());
}

级联属性可以修改属性的属性，原来的值会被修改。
引用时，会一改都改，值都会被修改。