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。

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