夜灬瞬

2022-04-05 11:09 江西工业贸易职业技术学院 Java

关注

XML注入其他类型属性

字面量

什么是字面量？

基本数据类型，决定值的对象都是字面量

null值

<null/>

</property>

xml配置

<?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">
    <!-- 配置对象的创建 -->
    <bean id="book" class="com.test.Book">
        <!--
        使用property完成属性注入
        name:类里面属性名称
        value：向属性注入的值
        -->
        <property name="name" value="第一本书"/>
        <property name="author" value="第一个作者"/>
        <!--
         向属性中设置空值
        -->
        <property name="address">
            <null/>
        </property>
    </bean>
</beans>

book

package com.test;

/**
 * 演示使用色图方法进行属性的注入
 */
public class Book {

    private String name;

    private String author;

    private String address;

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

    public void setName(String name) {
        this.name = name;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public void testDemo(){
        System.out.println(name + "::" + author + "::" + address);
    }
}

测试方法

package com.test;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import static org.junit.Assert.*;

public class BookTest {

    @Test
    public void testBook(){
        //1.加载spring配置文件
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        //2.获取配置创建的对象
        Book book = context.getBean("book", Book.class);
        System.out.println("book = " + book);
        book.testDemo();
    }
}

book = com.test.Book@43a0cee9

第一本书::第一个作者::null

属性值包含特殊符号

xml配置

<?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">
    <!-- 配置对象的创建 -->
    <bean id="book" class="com.test.Book">
        <!--
        使用property完成属性注入
        name:类里面属性名称
        value：向属性注入的值
        -->
        <property name="name" value="第一本书"/>
        <property name="author" value="第一个作者"/>
        <!--
         向属性中设置空值
        -->
        <!--<property name="address">
            <null/>
        </property>-->

        <!-- 属性值包含特殊符号 例如<南京>-->
        <!-- 第一种方式 转义 -->
        <!--<property name="address" value="&lt;南京&gt;"/>-->
        <!-- 第二种方式 把带特殊符号的内容写到CDATA中 -->
        <property name="address">
            <value>
                <![CDATA[<南京>]]>
            </value>
        </property>
    </bean>
</beans>

注入属性-注入外部bean

通过service层调用到层这样的过程就叫注入外部bean

第一步创建两个类service类和dao类

在service调用dao里面的方法

在spring配置文件中进行配置

service

package com.test.service;

import com.test.dao.UserDao;

public class UserService {

    /**
     * 创建UserDao的对象
     * 原始方式
     * private UserDao userDao = new UserDaoImpl();
     */

    //创建UserDao属性，生成set方法
    private UserDao userDao;

    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }

    public void add(){
        System.out.println("add....");
        userDao.update();
    }

}

dao

package com.test.dao;

public interface UserDao {

    public void update();
}

daoImpl

package com.test.dao.impl;

import com.test.dao.UserDao;

public class UserDaoImpl implements UserDao {
    @Override
    public void update() {
        System.out.println("dao update");
    }
}

xml

<?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">
    <!-- service和dao对象创建 -->
    <bean id="userService" class="com.test.service.UserService">
        <!--
        注入userDao对象
        name：类里面属性名称
        value：属性的值
        ref: 创建userDao对象bean标签的id值
        -->
        <property name="userDao" ref="userDao"/>
    </bean>
    <bean id="userDao" class="com.test.dao.impl.UserDaoImpl"/>
</beans>

测试

package com.test.service;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class UserServiceTest {

    @Test
    public void add() {
        //1、加载spring配置文件
        ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
        //获取配置创建的对象
        UserService userService = context.getBean("userService", UserService.class);
        System.out.println("userService = " + userService);
        userService.add();
    }
}

userService = com.test.service.UserService@150c158

add....

dao update

注入属性-内部bean和级联赋值

一对多关系

部门和员工是典型的一对多关系，一个部门里面有多个员工，一个员工属于某一个部门，部门是一，员工是多

在实体类之间表示一对多关系

package com.test.entity;

//部门类
public class Dept {

    private String name;

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Dept{" +
                "name='" + name + '\'' +
                '}';
    }
}

package com.test.entity;

//员工类
public class Emp {
    private String name;
    private String gender;

    //员工属于某一部门，使用对象形式表示
    private Dept dept;

    public void setDept(Dept dept) {
        this.dept = dept;
    }

    public void setName(String name) {
        this.name = name;
    }

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

    @Override
    public String toString() {
        return "Emp{" +
                "name='" + name + '\'' +
                ", gender='" + gender + '\'' +
                ", dept=" + dept +
                '}';
    }

    public void testEmp(){
        this.toString();
    }
}

<?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">
    <!-- 内部bean -->
    <bean id="emp" class="com.test.entity.Emp">
        <!-- 设置两个普通的属性 -->
        <property name="name" value="张三"/>
        <property name="gender" value="男"/>
        <!-- 设置对象类型属性 -->
        <!-- 方法一 引入外部bean -->
        <!--<property name="dept" ref="dept"/>-->
        <!-- 方法二 内部bean -->
        <property name="dept">
            <bean id="dept" class="com.test.entity.Dept">
                <property name="name" value="研发部"/>
            </bean>
        </property>
    </bean>
    <!--<bean id="dept" class="com.test.entity.Dept"/>-->
</beans>

package com.test.entity;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import static org.junit.Assert.*;

public class EmpTest {

    @Test
    public void testEmp() {
        //加载spring配置文件
        ApplicationContext context = new ClassPathXmlApplicationContext("spring1.xml");
        Emp emp = context.getBean("emp", Emp.class);
        System.out.println("emp = " + emp);
        emp.testEmp();
    }
}

级联赋值

第一种写法

<?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">
    <!-- 内部bean -->
    <bean id="emp" class="com.test.entity.Emp">
        <!-- 设置两个普通的属性 -->
        <property name="name" value="张三"/>
        <property name="gender" value="男"/>
        <!-- 级联赋值 -->
        <property name="dept" ref="dept"/>
    </bean>
    <bean id="dept" class="com.test.entity.Dept">
        <property name="name" value="研发部"/>
    </bean>
</beans>

@Test
    public void testEm1() {
        //加载spring配置文件
        ApplicationContext context = new ClassPathXmlApplicationContext("spring2.xml");
        Emp emp = context.getBean("emp", Emp.class);
        System.out.println("emp = " + emp);
        emp.testEmp();
    }

第二种写法

<?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">
    <!-- 内部bean -->
    <bean id="emp" class="com.test.entity.Emp">
        <!-- 设置两个普通的属性 -->
        <property name="name" value="张三"/>
        <property name="gender" value="男"/>
        <!-- 级联赋值 要有dept的get方法 -->
        <property name="dept.name" value="研发部"/>
    </bean>
    <bean id="dept" class="com.test.entity.Dept"/>
</beans>

package com.test.entity;

//员工类
public class Emp {
    private String name;
    private String gender;

    //员工属于某一部门，使用对象形式表示
    private Dept dept;

    public Dept getDept() {
        return dept;
    }

    public void setDept(Dept dept) {
        this.dept = dept;
    }

    public void setName(String name) {
        this.name = name;
    }

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

    @Override
    public String toString() {
        return "Emp{" +
                "name='" + name + '\'' +
                ", gender='" + gender + '\'' +
                ", dept=" + dept +
                '}';
    }

    public void testEmp(){
        this.toString();
    }
}

package com.test.entity;

//部门类
public class Dept {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "Dept{" +
                "name='" + name + '\'' +
                '}';
    }
}

xml注入集合属性

注入数组类型属性

注入List集合属性

注入Map集合类型属性

注入Set集合类型属性

package com.test1;

import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class Stu {
    //数组类型属性
    private String[] course;

    //list集合类型属性
    private List<String> list;

    //map集合类型属性
    private Map<String,String> map;

    //set集合类型属性
    private Set<String> set;

    public void setSet(Set<String> set) {
        this.set = set;
    }

    public void setList(List<String> list) {
        this.list = list;
    }

    public void setMap(Map<String, String> map) {
        this.map = map;
    }

    public void setCourse(String[] course) {
        this.course = course;
    }

    public void test(){
        System.out.println(Arrays.toString(course));
        System.out.println(list);
        System.out.println(map);
        System.out.println(set);
    }
}

<?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">
    <!-- 集合类型属性注入 -->
    <bean id="stu" class="com.test1.Stu">
        <!-- 数组类型属性注入 -->
        <property name="course">
            <!-- 也可以用list -->
            <array>
                <value>Java</value>
                <value>Mysql</value>
            </array>
        </property>
        <!-- list 类型属性注入 -->
        <property name="list">
            <list>
                <value>张三</value>
                <value>李四</value>
            </list>
        </property>
        <!-- map 类型属性注入 -->
        <property name="map">
            <map>
                <entry key="第一个" value="第一个值"/>
                <entry key="第二个" value="第二个值"/>
            </map>
        </property>
        <!-- set类型属性注入 -->
        <property name="set">
            <set>
                <value>set1</value>
                <value>set2</value>
            </set>
        </property>
    </bean>
</beans>

package com.test1;

import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import static org.junit.Assert.*;

public class StuTest {

    @Test
    public void test1() {
        ApplicationContext context = new ClassPathXmlApplicationContext("spring4.xml");
        Stu stu = context.getBean("stu", Stu.class);
        System.out.println(stu);
        stu.test();
    }
}

com.test1.Stu@768b970c

[Java, Mysql]

[张三, 李四]

{第一个=第一个值, 第二个=第二个值}

[set1, set2]

在集合里面设置对象类型值

<?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">
    <!-- 集合类型属性注入 -->
    <bean id="stu" class="com.test1.Stu">
        <!-- 数组类型属性注入 -->
        <property name="course">
            <!-- 也可以用list -->
            <array>
                <value>Java</value>
                <value>Mysql</value>
            </array>
        </property>
        <!-- list 类型属性注入 -->
        <property name="list">
            <list>
                <value>张三</value>
                <value>李四</value>
            </list>
        </property>
        <!-- map 类型属性注入 -->
        <property name="map">
            <map>
                <entry key="第一个" value="第一个值"/>
                <entry key="第二个" value="第二个值"/>
            </map>
        </property>
        <!-- set类型属性注入 -->
        <property name="set">
            <set>
                <value>set1</value>
                <value>set2</value>
            </set>
        </property>
        <!-- 注入list集合类型对象 值是对象 -->
        <property name="courseList">
            <list>
                <ref bean="course1"/>
                <ref bean="course2"/>
                <ref bean="course3"/>
            </list>
        </property>
    </bean>

    <!-- 创建多个course对象 -->
    <bean id="course1" class="com.test1.Course">
        <property name="cname" value="第一个"/>
    </bean>
    <bean id="course2" class="com.test1.Course">
        <property name="cname" value="第2个"/>
    </bean>
    <bean id="course3" class="com.test1.Course">
        <property name="cname" value="第3个"/>
    </bean>
</beans>

把集合注入部分提取出来

在spring配置文件中引入名称空间util

<?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/beans/spring-util.xsd">

</beans>

使用util标签完成list集合注入提取

<?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/beans/spring-util.xsd">
    <!-- 提取list集合类型属性注入 -->
    <util:list id="bookList">
        <value>第一本书</value>
        <value>第2本书</value>
        <value>第3本书</value>
    </util:list>

    <!-- 提取list集合类型属性注入使用 -->
    <bean id="book" class="com.test1.Book">
        <property name="list" ref="bookList"/>
    </bean>
</beans>

package com.test1;

import java.util.List;

public class Book {
    private List<String> list;

    public void setList(List<String> list) {
        this.list = list;
    }

    public void test(){
        System.out.println("list = " + list);
    }
}