目录
使用index标签属性：index的值为参数的顺序，默认从0开始
5、注入集合属性——数组、List集合、Map集合、Set集合
一、xml方式创建对象
<!-- 配置User对象创建-->
<!-- id是取得别名，通过id别名可以把类找到-->
<bean id="user" class="com.atguigu.spring5.User"></bean>- id：唯一标识，不能加特殊符号
- class：类全路经（包类路径）
- name：可以加特殊符号
二、xml方式注入属性
DI：依赖注入，就是注入属性
第①种方式注入：set方法注入
package com.atguigu.spring5.Book;
public class Book {
private String bname;
private String bauthor;
public void setBname(String bname){
this.bname=bname;
}
public void setBauthor(String bauthor){
this.bauthor=bauthor;
}
public static void main(String[] args) {
Book book = new Book();
book.setBname("abc");
}
public void testDemo(){
System.out.println(bname+"---"+bauthor);
}
}
<?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">
<!-- 2.set方法注入属性-->
<bean id="book" class="com.atguigu.spring5.Book.Book">
<!-- 使用propterty完成属性注入-->
<!-- name：类里面属性名称-->
<!-- value：向属性注入的值-->
<property name="bname" value="追风筝的人"></property>
<property name="bauthor" value="卡勒德·胡赛尼"></property>
</bean>
</beans>package com.atguigu.spring5.Book;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class BoolTestMain {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("Booktest.xml");
Book book = context.getBean("book", Book.class);
System.out.println(book);
book.testDemo();
}
}
我们还可以通过另一种方式简化写法—p名称空间注入
<?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:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="books" class="com.atguigu.spring5.Book.Book" p:bname="朝花夕拾" p:bauthor="鲁迅"></bean>
</beans>第②种方式注入：有参构造函数注入
public class Orders {
// 有参数构造注入属性
private String oname;
private String address;
private double money;
public Orders(String oname, String address, double money) {
this.oname = oname;
this.address = address;
this.money = money;
}
public void show() {
System.out.println(oname + "---" + address + "---" + money);
}
}constructor-arg：通过构造函数注入
使用value标签属性： 默认按照constructor-arg标签的顺序
<constructor-arg value="电脑"></constructor-arg>
<constructor-arg value="China"></constructor-arg>用name标签属性： 不按照顺序也会自动匹配
<constructor-arg name="oname" value="电脑"></constructor-arg>
<constructor-arg name="address" value="China"></constructor-arg>使用index标签属性：index的值为参数的顺序，默认从0开始
<!--index="0"：有参构造的第一个属性-->
<constructor-arg index="0" value="电脑"></constructor-arg>
<constructor-arg index="1" value="China"></constructor-arg>使用type标签属性：要和参数数据类型严格一致
（如果数据类型一致，按照constructor-arg标签的顺序匹配）
<constructor-arg type="double" value="23"></constructor-arg>
<constructor-arg type="java.lang.String" value="电脑"></constructor-arg>
<constructor-arg type="java.lang.String" value="China"></constructor-arg>三、xml注入其他类型属性
1、字面量--null值
<constructor-arg name="oname" value="朝花夕拾"/>
<constructor-arg name="oauthor" value="鲁迅"/>
<constructor-arg name="address" >
<null></null>
</constructor-arg>
2、含有特殊符号
- <；>；
- 把带特殊符号内容写到!CDATA
<!-- 1、使用<>先进行转义-->
<property name="bauthor" value="鲁迅"></property>
<property name="bname" value="<>朝花夕拾>>"></property>
<!-- 2、使用!CDATA-->
<property name="bauthor">
<value><![CDATA[<<南京>>]]></value>
</property>3、注入属性-外部bean
通过ref属性将进行注入
public class School {
//创建School类型属性，生成set方法
private Teacher teacher;
public void setTeacher(Teacher teacher) {
this.teacher = teacher;
}
}<!-- 注入外部bean-->
<bean id="school" class="com.atguigu.spring5.propertyTest.School">
<property name="teacher" ref="teachers"></property>
</bean>
<bean id="teachers" class="com.atguigu.spring5.propertyTest.Teacher"></bean>4、注入属性-内部bean
什么是内部bean？
在某一个bean中定义另一个bean作为属性
什么时候使用内部bean？
如果School类中的某个属性的数据类型是另一个类Book，则可以把这个类Book定义在属性的内部
如何使用内部bean？
public class School {
//创建School类型属性，生成set方法
private Teacher teacher;
public void setTeacher(Teacher teacher) {
this.teacher = teacher;
}
//部门
private Book dept;
public void setDept(Book dept) {
this.dept = dept;
}
}public class Book {
private String bname;
private String bauthor;
public void setBname(String bname) {
this.bname = bname;
}
} <!-- 注入内部bean-->
<bean id="school" class="com.atguigu.spring5.propertyTest.School">
<property name="teacher" ref="teachers"></property>
<property name="dept" >
<bean id="book" class="com.atguigu.spring5.Book.Book">
<property name="bname" value="朝花夕拾"></property>
</bean>
</property>
</bean>5、注入集合属性——数组、List集合、Map集合、Set集合
package com.atguigu.spring5.CollectionTypeTest;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* @BelongsProject: 02-Spring
* @BelongsPackage: com.atguigu.spring5.CollectionTypeTest
* @Author: dengLiMei
* @CreateTime: 2023-02-09 09:46
* @Description: TODO
* @Version: 1.0
*/
public class Student {
//数组
private String[] courses;
// List集合
private List<String> lists;
//Map集合
private Map<String, String> maps;
//Set集合
private Set<String> sets;
public void setSets(Set<String> sets) {
this.sets = sets;
}
public Student() {
}
public void setCourses(String[] courses) {
this.courses = courses;
}
public void setLists(List<String> lists) {
this.lists = lists;
}
public void setMaps(Map<String, String> maps) {
this.maps = maps;
}
public void show() {
System.out.println(Arrays.toString(courses));
System.out.println((lists));
System.out.println((maps));
System.out.println((sets));
}
}
<?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">
<bean id="students" class="com.atguigu.spring5.CollectionTypeTest.Student">
<!-- 数组-->
<property name="courses">
<array>
<value>spring5</value>
<value>springboot</value>
</array>
</property>
<!-- List类型-->
<property name="lists">
<list>
<value>springcloud</value>
<value>springcloudAlibaba</value>
</list>
</property>
<!-- Map集合-->
<property name="maps">
<map>
<entry key="QQ" value="腾讯"></entry>
<entry key="淘宝" value="阿里"></entry>
</map>
</property>
<!-- Set集合-->
<property name="sets">
<set>
<value>set-spring5</value>
<value>set-springboot</value>
</set>
</property>
</bean>
</beans>输出结果：
如果一个类中包含了另一个类的实体对象，可以这样写
public class Course {
// 课程名称
private String cname;
public void setCname(String cname) {
this.cname = cname;
}
}package com.atguigu.spring5.CollectionTypeTest;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class Student2 {
//实体对象-学生有多门课程
private List<Course> courseList;
public void setCourseList(List<Course> courseList) {
this.courseList = courseList;
}
@Override
public String toString() {
return "Student2{" +
"courseList=" + courseList +
'}';
}
}
<bean id="student2" class="com.atguigu.spring5.CollectionTypeTest.Student2">
<property name="courseList">
<list>
<ref bean="course1"></ref>
<ref bean="course2"></ref>
</list>
</property>
</bean>
<!-- 创建多个course对象-->
<bean id="course1" class="com.atguigu.spring5.CollectionTypeTest.Course">
<property name="cname" value="spring5框架"></property>
</bean>
<bean id="course2" class="com.atguigu.spring5.CollectionTypeTest.Course">
<property name="cname" value="MyBatis框架"></property>
</bean>public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("CollectionTypeBeans.xml");
Student2 students1 = context.getBean("student2", Student2.class);
students1.show();
}输出结果：
目前的问题：只能当前类使用，其他类不能用，接下来就是把集合属性抽取成公共部分让所有实体类都能够引入
抽取公共部分
public class Book {
private List<String> list;
public void setList(List<String> list) {
this.list = list;
}
public void show(){
System.out.println(list);
}
}<?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"
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.xsd">
<!-- 1、提取list集合类型属性注入-->
<util:list id="bookList">
<value>spring5</value>
<value>springboot</value>
<value>springcloud</value>
</util:list>
<!-- 2、提取list集合类型属性注入使用-->
<bean id="book" class="com.atguigu.spring5.CollectionTypeTest.Book">
<property name="list" ref="bookList"></property>
</bean>
</beans>public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("CollectionTypeBeans.xml");
Book book = context.getBean("book", Book.class);
book.show();
}输出结果：
