一、setter 注入Bean对象
1.创建Student对象
public class Student {private Integer id;private String name;private Integer age;private String sex;public Student() {}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}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 getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}@Overridepublic String toString() {return "Student{" +"id=" + id +", name='" + name + '\'' +", age=" + age +", sex='" + sex + '\'' +'}';}}2.配置 XML 文件的对象属性
<?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><bean id="student" class="Test.Student"><property name="id" value="1"></property><property name="name" value="张三"></property><property name="age" value="18"></property><property name="sex" value="男"></property></bean><bean id="student2" class="Test.Student"><property name="id" value="2"></property><property name="name" value="李四"></property><property name="age" value="20"></property><property name="sex" value="男"></property></bean>
</beans>3.创建测试类
public class StudentTest {public static void main(String[] args) {ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");Student student = (Student) applicationContext.getBean("student");System.out.println(student);Student student2 = (Student) applicationContext.getBean("student2");System.out.println(student2);}
}
二、构造器注入
1.Student类中添加有参构造方法
public Student(Integer id, String name, Integer age, String sex) {this.id = id;this.name = name;this.age = age;this.sex = sex;
}2.配置 XML 文件的对象属性
<?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="student3" class="Test.Student"><constructor-arg name="id" value="3"></constructor-arg><constructor-arg name="name" value="王五"></constructor-arg><constructor-arg name="age" value="22"></constructor-arg><constructor-arg name="sex" value="女"></constructor-arg></bean>
</beans>注意：constructor-arg标签还有两个属性可以进一步描述构造器参数：
-
index属性：指定参数所在位置的索引（从0开始）
-
name属性：指定参数名
3.创建测试类
public class StudentTest {public static void main(String[] args) {ApplicationContext applicationContext = new ClassPathXmlApplicationContext("beans.xml");Student student3 = (Student) applicationContext.getBean("student3");System.out.println(student3);}
}
三、特殊值处理
1.字面量赋值
<br class="Apple-interchange-newline"><div></div>
<!-- 使用value属性给bean的属性赋值时，Spring会把value属性的值看做字面量 -->
<property name="name" value="张三"/>2.Null 值赋值
<property name="name"><null />
</property>注意：以下会将值赋值为null而不是空值
<property name="name" value="null"></property>3.xml实体
<!-- 小于号在XML文档中用来定义标签的开始，不能随便使用 -->
<!-- 解决方案一：使用XML实体来代替 -->
<property name="expression" value="a < b"/>4.CDATA节
<property name="expression"><!-- 解决方案二：使用CDATA节 --><!-- CDATA中的C代表Character，是文本、字符的含义，CDATA就表示纯文本数据 --><!-- XML解析器看到CDATA节就知道这里是纯文本，就不会当作XML标签或属性来解析 --><!-- 所以CDATA节中写什么符号都随意 --><value><![CDATA[a < b]]></value>
</property>四、为复杂对象赋值
方式一：
1.配置嵌套内部的Clazz类型的bean：
<bean id="clazzOne" class="com.atguigu.spring6.bean.Clazz"><property name="clazzId" value="1111"></property><property name="clazzName" value="财源滚滚班"></property>
</bean>2.为Student中的clazz属性赋值
<bean id="studentFour" class="com.atguigu.spring6.bean.Student"><property name="id" value="1004"></property><property name="name" value="赵六"></property><property name="age" value="26"></property><property name="sex" value="女"></property><!-- ref属性：引用IOC容器中某个bean的id，将所对应的bean为属性赋值 --><property name="clazz" ref="clazzOne"></property>
</bean>错误演示：
<bean id="studentFour" class="com.atguigu.spring6.bean.Student"><property name="id" value="1004"></property><property name="name" value="赵六"></property><property name="age" value="26"></property><property name="sex" value="女"></property><property name="clazz" value="clazzOne"></property>
</bean>方式二：内部bean
<bean id="studentFour" class="com.atguigu.spring6.bean.Student"><property name="id" value="1004"></property><property name="name" value="赵六"></property><property name="age" value="26"></property><property name="sex" value="女"></property><property name="clazz"><!-- 在一个bean中再声明一个bean就是内部bean --><!-- 内部bean只能用于给属性赋值，不能在外部通过IOC容器获取，因此可以省略id属性 --><bean id="clazzInner" class="com.atguigu.spring6.bean.Clazz"><property name="clazzId" value="2222"></property><property name="clazzName" value="远大前程班"></property></bean></property>
</bean>方式三：级联属性赋值
<bean id="studentFour" class="com.atguigu.spring6.bean.Student"><property name="id" value="1004"></property><property name="name" value="赵六"></property><property name="age" value="26"></property><property name="sex" value="女"></property><property name="clazz" ref="clazzOne"></property><property name="clazz.clazzId" value="3333"></property><property name="clazz.clazzName" value="最强王者班"></property>
</bean>五、为数组类型属性赋值
1.为Student类添加数组类型
private String[] hobbies;public String[] getHobbies() {return hobbies;
}public void setHobbies(String[] hobbies) {this.hobbies = hobbies;
}2.XML文件的Bean对象的配置
<bean id="studentFour" class="com.atguigu.spring.bean6.Student"><property name="id" value="1004"></property><property name="name" value="赵六"></property><property name="age" value="26"></property><property name="sex" value="女"></property><!-- ref属性：引用IOC容器中某个bean的id，将所对应的bean为属性赋值 --><property name="clazz" ref="clazzOne"></property><property name="hobbies"><array><value>抽烟</value><value>喝酒</value><value>烫头</value></array></property>
</bean>六、为集合类型属性赋值
List集合类型赋值：
1.在Clazz类中添加以下代码：
private List<Student> students;public List<Student> getStudents() {return students;
}public void setStudents(List<Student> students) {this.students = students;
}2.配置XML文件的 bean 对象
<bean id="clazzTwo" class="com.atguigu.spring6.bean.Clazz"><property name="clazzId" value="4444"></property><property name="clazzName" value="Javaee0222"></property><property name="students"><list><ref bean="studentOne"></ref><ref bean="studentTwo"></ref><ref bean="studentThree"></ref></list></property>
</bean>Map集合类型赋值：
1.在Student类中添加以下代码
private Map<String, Teacher> teacherMap;public Map<String, Teacher> getTeacherMap() {return teacherMap;
}public void setTeacherMap(Map<String, Teacher> teacherMap) {this.teacherMap = teacherMap;
}2.配置XML文件的bean：
<bean id="teacherOne" class="com.atguigu.spring6.bean.Teacher"><property name="teacherId" value="10010"></property><property name="teacherName" value="大宝"></property>
</bean><bean id="teacherTwo" class="com.atguigu.spring6.bean.Teacher"><property name="teacherId" value="10086"></property><property name="teacherName" value="二宝"></property>
</bean><bean id="studentFour" class="com.atguigu.spring6.bean.Student"><property name="id" value="1004"></property><property name="name" value="赵六"></property><property name="age" value="26"></property><property name="sex" value="女"></property><!-- ref属性：引用IOC容器中某个bean的id，将所对应的bean为属性赋值 --><property name="clazz" ref="clazzOne"></property><property name="hobbies"><array><value>抽烟</value><value>喝酒</value><value>烫头</value></array></property><property name="teacherMap"><map><entry><key><value>10010</value></key><ref bean="teacherOne"></ref></entry><entry><key><value>10086</value></key><ref bean="teacherTwo"></ref></entry></map></property>
</bean>引用集合类型的bean：
<!--list集合类型的bean-->
<util:list id="students"><ref bean="studentOne"></ref><ref bean="studentTwo"></ref><ref bean="studentThree"></ref>
</util:list>
<!--map集合类型的bean-->
<util:map id="teacherMap"><entry><key><value>10010</value></key><ref bean="teacherOne"></ref></entry><entry><key><value>10086</value></key><ref bean="teacherTwo"></ref></entry>
</util:map>
<bean id="clazzTwo" class="com.atguigu.spring6.bean.Clazz"><property name="clazzId" value="4444"></property><property name="clazzName" value="Javaee0222"></property><property name="students" ref="students"></property>
</bean>
<bean id="studentFour" class="com.atguigu.spring6.bean.Student"><property name="id" value="1004"></property><property name="name" value="赵六"></property><property name="age" value="26"></property><property name="sex" value="女"></property><!-- ref属性：引用IOC容器中某个bean的id，将所对应的bean为属性赋值 --><property name="clazz" ref="clazzOne"></property><property name="hobbies"><array><value>抽烟</value><value>喝酒</value><value>烫头</value></array></property><property name="teacherMap" ref="teacherMap"></property>
</bean>
