• (续)SSM整合之spring笔记(IOC 依赖注入之为属性赋值)（P073—P077）

    2.7  实验六：依赖注入之为类类型属性赋值

    模拟班级和学生  一对多的关系

    ①创建班级类Clazz 

    1. package com.atguigu.spring.pojo;
    2.  
    3. public class Clazz {
    4.     private Integer cid;
    5.  
    6.     private String cname;
    7.  
    8.     public Clazz() {
    9.     }
    10.  
    11.     public Clazz(Integer cid, String cname) {
    12.         this.cid = cid;
    13.         this.cname = cname;
    14.     }
    15.  
    16.     public Integer getCid() {
    17.         return cid;
    18.     }
    19.  
    20.     public void setCid(Integer cid) {
    21.         this.cid = cid;
    22.     }
    23.  
    24.     public String getCname() {
    25.         return cname;
    26.     }
    27.  
    28.     public void setCname(String cname) {
    29.         this.cname = cname;
    30.     }
    31.  
    32.     @Override
    33.     public String toString() {
    34.         return "Clazz{" +
    35.                 "cid=" + cid +
    36.                 ", cname='" + cname + '\'' +
    37.                 '}';
    38.     }
    39. }

    ②修改Student类

    通过实体类来表示学生和班级之间的关系

        对一：对应的是对象   对多：对应的是集合

    具体做法：

    在学生（多）里面设置一个班级（一）类型的属性  在设置get/set方法  重写tostring方法

    1. package com.atguigu.spring.pojo;
    2.  
    3. public class Student  implements Person {
    4.  
    5.     private Integer sid;
    6.  
    7.     private String sname;
    8.  
    9.     private Integer age;
    10.  
    11.     private String gender;
    12.  
    13.     private Double score;
    14.  
    15.     private Clazz clazz;
    16.  
    17.  
    18.     public Student() {
    19.     }
    20.  
    21.     public Student(Integer sid, String sname ,String gender , Integer age ) {
    22.         this.sid = sid;
    23.         this.sname = sname;
    24.         this.age = age;
    25.         this.gender = gender;
    26.     }
    27.  
    28.  
    29.     public Student(Integer sid, String sname, String gender, Double score) {
    30.         this.sid = sid;
    31.         this.sname = sname;
    32.         this.gender = gender;
    33.         this.score = score;
    34.     }
    35.  
    36.     public Integer getSid() {
    37.         return sid;
    38.     }
    39.  
    40.     public void setSid(Integer sid) {
    41.         this.sid = sid;
    42.     }
    43.  
    44.     public String getSname() {
    45.         return sname;
    46.     }
    47.  
    48.     public void setSname(String sname) {
    49.         this.sname = sname;
    50.     }
    51.  
    52.     public Integer getAge() {
    53.         return age;
    54.     }
    55.  
    56.     public void setAge(Integer age) {
    57.         this.age = age;
    58.     }
    59.  
    60.     public String getGender() {
    61.         return gender;
    62.     }
    63.  
    64.     public void setGender(String gender) {
    65.         this.gender = gender;
    66.     }
    67.  
    68.  
    69.     public Double getScore() {
    70.         return score;
    71.     }
    72.  
    73.     public void setScore(Double score) {
    74.         this.score = score;
    75.     }
    76.  
    77.  
    78.  
    79.  
    80.     public Clazz getClazz() {
    81.         return clazz;
    82.     }
    83.  
    84.     public void setClazz(Clazz clazz) {
    85.         this.clazz = clazz;
    86.     }
    87.  
    88.     @Override
    89.     public String toString() {
    90.         return "Student{" +
    91.                 "sid=" + sid +
    92.                 ", sname='" + sname + '\'' +
    93.                 ", age=" + age +
    94.                 ", gender='" + gender + '\'' +
    95.                 ", score=" + score +
    96.                 ", clazz=" + clazz +
    97.                 '}';
    98.     }
    99. }
    100.

    不能够用value赋值 因为value对应的是字面量 而clazz 不是字面量，clazz对应的是一个对象

    ③给类类型赋值的三种方式

    我们要给类类型赋值的话 我们有三种方式：

    方式一：引用外部已声明的 bean
    方式二：内部 bean
    方式三：级联属性赋值

    ①方式一：引用外部已声明的bean

    配置 Clazz 类型的 bean ： 
    1.         
    2.     <bean id="clazzOne" class="com.atguigu.spring.pojo.Clazz">
    3.         <property name="cid" value="1111">property>
    4.         <property name="cname" value="最强王者班">property>
    5.     bean>
    为 Student 中的 clazz 属性赋值： 
    1.          
    2.     <bean id="studentFive" class="com.atguigu.spring.pojo.Student">
    3.         <property name="sid" value="1004">property>
    4.         <property name="sname" value="赵六">property>
    5.         <property name="age" value="26">property>
    6.         <property name="gender" value="男">property>
    7.         
    8.         <property name="clazz" ref="clazzOne">property>
    9.     bean>

    合起来：

    1.    
    2.     <bean id="studentFive" class="com.atguigu.spring.pojo.Student">
    3.         <property name="sid" value="1004">property>
    4.         <property name="sname" value="赵六">property>
    5.         <property name="age" value="26">property>
    6.         <property name="gender" value="男">property>
    7.         
    8.         <property name="clazz" ref="clazzOne">property>
    9.     bean>
    10.  
    11.      
    12.     <bean id="clazzOne" class="com.atguigu.spring.pojo.Clazz">
    13.         <property name="cid" value="1111">property>
    14.         <property name="cname" value="最强王者班">property>
    15.     bean>

    测试

    1.     @Test
    2.     public void testDI(){
    3.         //获取IOC容器
    4.         ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-ioc.xml");
    5.         //获取bean
    6.         Student student = ioc.getBean("studentFive", Student.class);
    7.         System.out.println(student);
    8.     }

    ② 方式二：级联属性赋值(用得不多)   2222，远大前程班会覆盖   11111 最强王者班 

    1.            
    2.     
    3.     <bean id="studentFive" class="com.atguigu.spring.pojo.Student">
    4.         <property name="sid" value="1004">property>
    5.         <property name="sname" value="赵六">property>
    6.         <property name="age" value="26">property>
    7.         <property name="gender" value="男">property>
    8.         
    9.         <property name="clazz" ref="clazzOne">property>
    10.         <property name="clazz.cid" value="2222">property>
    11.         <property name="clazz.cname" value="远大前程班">property>
    12.  
    13.     bean>
    14.     
    15.     
    16.     <bean id="clazzOne" class="com.atguigu.spring.pojo.Clazz">
    17.         <property name="cid" value="1111">property>
    18.         <property name="cname" value="最强王者班">property>
    19.     bean>

    测试

    1.     @Test
    2.     public void testDI(){
    3.         //获取IOC容器
    4.         ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-ioc.xml");
    5.         //获取bean
    6.         Student student = ioc.getBean("studentFive", Student.class);
    7.         System.out.println(student);
    8.     }

    ③方式三 ：内部bean 

    1.       
    2.     <bean id="studentFive" class="com.atguigu.spring.pojo.Student">
    3.         <property name="sid" value="1004">property>
    4.         <property name="sname" value="赵六">property>
    5.         <property name="age" value="26">property>
    6.         <property name="gender" value="男">property>
    7.         <property name="clazz">
    8.             
    9.             <bean id="clazzInner" class="com.atguigu.spring.pojo.Clazz">
    10.                 <property name="cid" value="2222">property>
    11.                 <property name="cname" value="远大前程班">property>
    12.             bean>
    13.         property>
    14.     bean>
    15.  
    16.     
    17.     <bean id="clazzOne" class="com.atguigu.spring.pojo.Clazz">
    18.         <property name="cid" value="1111">property>
    19.         <property name="cname" value="最强王者班">property>
    20.     bean>

    测试：

    1.     @Test
    2.     public void testDI(){
    3.         //获取IOC容器
    4.         ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-ioc.xml");
    5.         //获取bean
    6.         Student student = ioc.getBean("studentFive", Student.class);
    7.         System.out.println(student);
    8.     }

    内部bean能够通过ioc直接获取获取吗？

    不能，内部bean，只能在当前bean的内部使用，不能直接通过IOC容器获取

    测试：

    1.     @Test
    2.     public void testDI(){
    3.         //获取IOC容器
    4.         ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-ioc.xml");
    5.         //获取bean
    6.        // Student student = ioc.getBean("studentTwo", Student.class);
    7.         Student student = ioc.getBean("studentFive", Student.class);
    8.         Clazz clazz = ioc.getBean("clazzInner", Clazz.class);
    9.         System.out.println(clazz);
    10.     }

     报错：

    org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'clazzInner' available

    没有一个bean叫做clazzInner被发现  没有一个叫做clazzInner的bean可用 

    available：可用

    2. 8 实验七：为数组类型属性赋值

    ①修改Student类 

    1. package com.atguigu.spring.pojo;
    2.  
    3. import java.util.Arrays;
    4.  
    5. public class Student  implements Person {
    6.  
    7.     private Integer sid;
    8.  
    9.     private String sname;
    10.  
    11.     private Integer age;
    12.  
    13.     private String gender;
    14.  
    15.     private Double score;
    16.  
    17.     private Clazz clazz;
    18.  
    19.     private String[] hobby;
    20.  
    21.  
    22.  
    23.  
    24.     public Student() {
    25.     }
    26.  
    27.     public Student(Integer sid, String sname ,String gender , Integer age ) {
    28.         this.sid = sid;
    29.         this.sname = sname;
    30.         this.age = age;
    31.         this.gender = gender;
    32.     }
    33.  
    34.  
    35.     public Student(Integer sid, String sname, String gender, Double score) {
    36.         this.sid = sid;
    37.         this.sname = sname;
    38.         this.gender = gender;
    39.         this.score = score;
    40.     }
    41.  
    42.     public Integer getSid() {
    43.         return sid;
    44.     }
    45.  
    46.     public void setSid(Integer sid) {
    47.         this.sid = sid;
    48.     }
    49.  
    50.     public String getSname() {
    51.         return sname;
    52.     }
    53.  
    54.     public void setSname(String sname) {
    55.         this.sname = sname;
    56.     }
    57.  
    58.     public Integer getAge() {
    59.         return age;
    60.     }
    61.  
    62.     public void setAge(Integer age) {
    63.         this.age = age;
    64.     }
    65.  
    66.     public String getGender() {
    67.         return gender;
    68.     }
    69.  
    70.     public void setGender(String gender) {
    71.         this.gender = gender;
    72.     }
    73.  
    74.  
    75.     public Double getScore() {
    76.         return score;
    77.     }
    78.  
    79.     public void setScore(Double score) {
    80.         this.score = score;
    81.     }
    82.  
    83.     
    84.     public Clazz getClazz() {
    85.         return clazz;
    86.     }
    87.  
    88.     public void setClazz(Clazz clazz) {
    89.         this.clazz = clazz;
    90.     }
    91.  
    92.  
    93.     public String[] getHobby() {
    94.         return hobby;
    95.     }
    96.  
    97.     public void setHobby(String[] hobby) {
    98.         this.hobby = hobby;
    99.     }
    100.  
    101.     @Override
    102.     public String toString() {
    103.         return "Student{" +
    104.                 "sid=" + sid +
    105.                 ", sname='" + sname + '\'' +
    106.                 ", age=" + age +
    107.                 ", gender='" + gender + '\'' +
    108.                 ", score=" + score +
    109.                 ", clazz=" + clazz +
    110.                 ", hobby=" + Arrays.toString(hobby) +
    111.                 '}';
    112.     }
    113. }

    ②配置bean 

    1.   
    2.  
    3.     <bean id="studentFive" class="com.atguigu.spring.pojo.Student">
    4.         <property name="sid" value="1004">property>
    5.         <property name="sname" value="赵六">property>
    6.         <property name="age" value="26">property>
    7.         <property name="gender" value="男">property>
    8.  
    9.         <property name="clazz">
    10.           
    11.             <bean id="clazzInner" class="com.atguigu.spring.pojo.Clazz">
    12.                 <property name="cid" value="2222">property>
    13.                 <property name="cname" value="远大前程班">property>
    14.             bean>
    15.         property>
    16.  
    17.          
    18.         <property name="hobby">
    19.             <array>
    20.                 <value>抽烟value>
    21.                 <value>喝酒value>
    22.                 <value>烫头value>
    23.             array>
    24.         property>
    25.         
    26.         
    27.     bean>
    28.  
    29.     
    30.     <bean id="clazzOne" class="com.atguigu.spring.pojo.Clazz">
    31.         <property name="cid" value="1111">property>
    32.         <property name="cname" value="最强王者班">property>
    33.     bean>

     测试：

     2.9 实验八：为集合类型属性赋值

    ①为List集合类型属性赋值

    在 Clazz 类中添加以下代码： 
    1. package com.atguigu.spring.pojo;
    2.  
    3. import java.util.List;
    4.  
    5. public class Clazz {
    6.     private Integer cid;
    7.  
    8.     private String cname;
    9.  
    10.     private List students;
    11.  
    12.  
    13.     public Clazz() {
    14.     }
    15.  
    16.     public Clazz(Integer cid, String cname) {
    17.         this.cid = cid;
    18.         this.cname = cname;
    19.     }
    20.  
    21.     public Integer getCid() {
    22.         return cid;
    23.     }
    24.  
    25.     public void setCid(Integer cid) {
    26.         this.cid = cid;
    27.     }
    28.  
    29.     public String getCname() {
    30.         return cname;
    31.     }
    32.  
    33.     public void setCname(String cname) {
    34.         this.cname = cname;
    35.     }
    36.  
    37.  
    38.     public List getStudents() {
    39.         return students;
    40.     }
    41.  
    42.     public void setStudents(List students) {
    43.         this.students = students;
    44.     }
    45.  
    46.     @Override
    47.     public String toString() {
    48.         return "Clazz{" +
    49.                 "cid=" + cid +
    50.                 ", cname='" + cname + '\'' +
    51.                 ", students=" + students +
    52.                 '}';
    53.     }
    54. }
    配置 bean ： 
    1.   
    2.     <bean id="clazzOne" class="com.atguigu.spring.pojo.Clazz">
    3.         <property name="cid" value="1111">property>
    4.         <property name="cname" value="最强王者班">property>
    5.  
    6.         <property name="students">
    7.                     <list>
    8.                         <ref bean="studentOne">ref>
    9.                         <ref bean="studentTwo">ref>
    10.                         <ref bean="studentThree">ref>
    11.                     list>
    12.         property>
    13.  
    14.     bean>

    测试：

    1.     @Test
    2.     public void testDI(){
    3.         //获取IOC容器
    4.         ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-ioc.xml");
    5.         //获取bean
    6.         Clazz clazz = ioc.getBean("clazzOne", Clazz.class);
    7.         System.out.println(clazz);

     另一种方式    配置一个集合类型的bean，需要使用util的约束

     

    xmlns:util="http://www.springframework.org/schema/util"
    1.     
    2.     <bean id="clazzOne" class="com.atguigu.spring.pojo.Clazz">
    3.         <property name="cid" value="1111">property>
    4.         <property name="cname" value="最强王者班">property>
    5.         <property name="students" ref="studentList">property>
    6.  
    7.      
    8.  
    9.     bean>
    10.  
    11.  
    12.     
    13.     <util:list id="studentList">
    14.         <ref bean="studentOne">ref>
    15.         <ref bean="studentTwo">ref>
    16.         <ref bean="studentThree">ref>
    17.     util:list>

    测试

    1.     @Test
    2.     public void testDI(){
    3.         //获取IOC容器
    4.         ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-ioc.xml");
    5.         //获取bean
    6.         Clazz clazz = ioc.getBean("clazzOne", Clazz.class);
    7.         System.out.println(clazz);

     

    ②为Map集合类型属性赋值

    创建教师类 Teacher ： 
    1. package com.atguigu.spring.pojo;
    2.  
    3. /**
    4.  * Date:2022/7/1
    5.  * Author:ybc
    6.  * Description:
    7.  */
    8. public class Teacher {
    9.  
    10.     private Integer tid;
    11.  
    12.     private String tname;
    13.  
    14.     @Override
    15.     public String toString() {
    16.         return "Teacher{" +
    17.                 "tid=" + tid +
    18.                 ", tname='" + tname + '\'' +
    19.                 '}';
    20.     }
    21.  
    22.     public Integer getTid() {
    23.         return tid;
    24.     }
    25.  
    26.     public void setTid(Integer tid) {
    27.         this.tid = tid;
    28.     }
    29.  
    30.     public String getTname() {
    31.         return tname;
    32.     }
    33.  
    34.     public void setTname(String tname) {
    35.         this.tname = tname;
    36.     }
    37.  
    38.     public Teacher() {
    39.     }
    40.  
    41.     public Teacher(Integer tid, String tname) {
    42.         this.tid = tid;
    43.         this.tname = tname;
    44.     }
    45. }
    46.
    在 Student 类中添加以下代码：

     

    1. package com.atguigu.spring.pojo;
    2.  
    3. import java.util.Arrays;
    4. import java.util.Map;
    5.  
    6. public class Student  implements Person {
    7.  
    8.     private Integer sid;
    9.  
    10.     private String sname;
    11.  
    12.     private Integer age;
    13.  
    14.     private String gender;
    15.  
    16.     private Double score;
    17.  
    18.     private Clazz clazz;
    19.  
    20.     private String[] hobby;
    21.  
    22.     private Map teacherMap;
    23.  
    24.  
    25.  
    26.  
    27.     public Student() {
    28.     }
    29.  
    30.     public Student(Integer sid, String sname ,String gender , Integer age ) {
    31.         this.sid = sid;
    32.         this.sname = sname;
    33.         this.age = age;
    34.         this.gender = gender;
    35.     }
    36.  
    37.  
    38.     public Student(Integer sid, String sname, String gender, Double score) {
    39.         this.sid = sid;
    40.         this.sname = sname;
    41.         this.gender = gender;
    42.         this.score = score;
    43.     }
    44.  
    45.     public Integer getSid() {
    46.         return sid;
    47.     }
    48.  
    49.     public void setSid(Integer sid) {
    50.         this.sid = sid;
    51.     }
    52.  
    53.     public String getSname() {
    54.         return sname;
    55.     }
    56.  
    57.     public void setSname(String sname) {
    58.         this.sname = sname;
    59.     }
    60.  
    61.     public Integer getAge() {
    62.         return age;
    63.     }
    64.  
    65.     public void setAge(Integer age) {
    66.         this.age = age;
    67.     }
    68.  
    69.     public String getGender() {
    70.         return gender;
    71.     }
    72.  
    73.     public void setGender(String gender) {
    74.         this.gender = gender;
    75.     }
    76.  
    77.  
    78.     public Double getScore() {
    79.         return score;
    80.     }
    81.  
    82.     public void setScore(Double score) {
    83.         this.score = score;
    84.     }
    85.  
    86.  
    87.     public Clazz getClazz() {
    88.         return clazz;
    89.     }
    90.  
    91.     public void setClazz(Clazz clazz) {
    92.         this.clazz = clazz;
    93.     }
    94.  
    95.  
    96.     public String[] getHobby() {
    97.         return hobby;
    98.     }
    99.  
    100.     public void setHobby(String[] hobby) {
    101.         this.hobby = hobby;
    102.     }
    103.  
    104.  
    105.     public Map getTeacherMap() {
    106.         return teacherMap;
    107.     }
    108.  
    109.     public void setTeacherMap(Map teacherMap) {
    110.         this.teacherMap = teacherMap;
    111.     }
    112.  
    113.     @Override
    114.     public String toString() {
    115.         return "Student{" +
    116.                 "sid=" + sid +
    117.                 ", sname='" + sname + '\'' +
    118.                 ", age=" + age +
    119.                 ", gender='" + gender + '\'' +
    120.                 ", score=" + score +
    121.                 ", clazz=" + clazz +
    122.                 ", hobby=" + Arrays.toString(hobby) +
    123.                 ", teacherMap=" + teacherMap +
    124.                 '}';
    125.     }
    126. }
    第一种方式： 配置 bean ： 
    1.     
    2.     <bean id="studentFive" class="com.atguigu.spring.pojo.Student">
    3.         <property name="sid" value="1004">property>
    4.         <property name="sname" value="赵六">property>
    5.         <property name="age" value="26">property>
    6.         <property name="gender" value="男">property>
    7.         <property name="clazz">
    8.             
    9.             <bean id="clazzInner" class="com.atguigu.spring.pojo.Clazz">
    10.                 <property name="cid" value="2222">property>
    11.                 <property name="cname" value="远大前程班">property>
    12.             bean>
    13.         property>
    14.         <property name="hobby">
    15.             <array>
    16.                 <value>抽烟value>
    17.                 <value>喝酒value>
    18.                 <value>烫头value>
    19.             array>
    20.         property>
    21.  
    22.         <property name="teacherMap">
    23.             <map>
    24.                 <entry key="10086" value-ref="teacherOne">entry>
    25.                 <entry key="10010" value-ref="teacherTwo">entry>
    26.             map>
    27.         property>
    28.     bean>
    29.  
    30.  
    31.     <bean id="teacherOne" class="com.atguigu.spring.pojo.Teacher">
    32.         <property name="tid" value="10086">property>
    33.         <property name="tname" value="大宝">property>
    34.     bean>
    35.  
    36.     <bean id="teacherTwo" class="com.atguigu.spring.pojo.Teacher">
    37.         <property name="tid" value="10010">property>
    38.         <property name="tname" value="小宝">property>
    39.     bean>
    40. beans>
    测试 
    1.    @Test
    2.     public void testDI(){
    3.         //获取IOC容器
    4.         ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-ioc.xml");
    5.         //获取bean  
    6.          Student student = ioc.getBean("studentFive", Student.class);
    7.          System.out.println(student);     
    8.     }

     

    第二种方式： 配置 bean 
    1.          
    2.     <bean id="studentFive" class="com.atguigu.spring.pojo.Student">
    3.         <property name="sid" value="1004">property>
    4.         <property name="sname" value="赵六">property>
    5.         <property name="age" value="26">property>
    6.         <property name="gender" value="男">property>
    7.         <property name="clazz">
    8.             
    9.             <bean id="clazzInner" class="com.atguigu.spring.pojo.Clazz">
    10.                 <property name="cid" value="2222">property>
    11.                 <property name="cname" value="远大前程班">property>
    12.             bean>
    13.         property>
    14.         <property name="hobby">
    15.             <array>
    16.                 <value>抽烟value>
    17.                 <value>喝酒value>
    18.                 <value>烫头value>
    19.             array>
    20.         property>
    21.         <property name="teacherMap" ref="teacherMap">property>
    22.       
    23.     bean>
    24.  
    25.  
    26.     <bean id="teacherOne" class="com.atguigu.spring.pojo.Teacher">
    27.         <property name="tid" value="10086">property>
    28.         <property name="tname" value="大宝">property>
    29.     bean>
    30.  
    31.     <bean id="teacherTwo" class="com.atguigu.spring.pojo.Teacher">
    32.         <property name="tid" value="10010">property>
    33.         <property name="tname" value="小宝">property>
    34.     bean>
    35.  
    36.     <util:map id="teacherMap">
    37.         <entry key="10086" value-ref="teacherOne">entry>
    38.         <entry key="10010" value-ref="teacherTwo">entry>
    39.     util:map>
    1.    @Test
    2.     public void testDI(){
    3.         //获取IOC容器
    4.         ApplicationContext ioc = new ClassPathXmlApplicationContext("spring-ioc.xml");
    5.         //获取bean
    6.          Student student = ioc.getBean("studentFive", Student.class);
    7.        System.out.println(student);
    8.     
    9.  
    10.     }

     

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  • 原文地址：https://blog.csdn.net/m0_59281987/article/details/127605000