基於 xml 方式的bean管理
技術標籤:Spring
1、基於 xml 方式建立物件
(1)在 spring 配置檔案,使用 bean 標籤,標籤裡面新增對應屬性,就可以實現物件建立
(2)在 bean 標籤有很多屬性,介紹常用的屬性
- id 屬性:唯一標識
- class 屬性:類全路徑(包類路徑)
(3)建立物件時候,預設也是執行無引數構造方法完成物件建立
2、基於 xml 方式注入屬性
(1)DI:依賴注入,就是注入屬性
3、第一種注入方式:使用 set 方法進行注入
(1)建立類,定義屬性和對應的 set 方法
public class Book {
//建立屬性
private String bname;
private String bauthor;
//建立屬性對應的 set 方法
public void setBname(String bname) {
this.bname = bname;
}
public void setBauthor(String bauthor) {
this.bauthor = bauthor;
}
public String toString() {
return "Book{" +
"bname='" + bname + '\'' +
", bauthor='" + bauthor + '\'' +
'}';
}
}
(2)在 spring 配置檔案配置物件建立,配置屬性注入
<!--2set方法注入屬性-->
<bean id="book" class="com.atguigu.spring5.Book">
<!--使用property屬性完成屬性注入
name:類裡面的屬性名稱
value:向屬性中注入的值
-->
<property name="bname" value="java學習指南"></property>
<property name="bauthor" value="大佬"></property>
</bean>
(3)測試
@Test
public void testBook(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean1.xml");
//2獲取配置建立的物件
Book book = context.getBean ("book", Book.class);
System.out.println (book);
}
(4)結果
4、第二種注入方式:使用有引數構造進行注入
(1)建立類,定義屬性和有引數的構造方法
public class Orders {
//屬性
private String oname;
private String address;
//有引數構造
public Orders(String oname, String address) {
this.oname = oname;
this.address = address;
}
public String toString() {
return "Orders{" +
"oname='" + oname + '\'' +
", address='" + address + '\'' +
'}';
}
}
(2)在 spring 配置檔案中進行配置
<!--3使用構造方法進行熟屬性注入-->
<bean id="orders" class="com.atguigu.spring5.Orders">
<constructor-arg name="oname" value="電腦"></constructor-arg>
<constructor-arg name="address" value="china"></constructor-arg>
</bean>
(3)測試
@Test
public void testOrders(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean1.xml");
//2獲取配置建立的物件
Orders orders = context.getBean ("orders", Orders.class);
System.out.println (orders);
}
(4)結果
第三種注入方式: p 名稱空間注入
(1)新增 p 名稱空間在配置檔案中
在約束中增加:xmlns:p="http://www.springframework.org/schema/p"
(2)進行屬性注入,在 bean 標籤裡面進行操作
<!--4p名稱空間注入-->
<bean id="book1" class="com.atguigu.spring5.Book" p:bauthor="絕世神功" p:bname="帶佬"></bean>
(3)測試
@Test
public void testp(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean1.xml");
//2獲取配置建立的物件
Book book1 = context.getBean ("book1", Book.class);
System.out.println (book1);
}
(4)結果
xml 注入其他型別屬性
1、字面量null 值
(1)null 值在xml中配置
<!--5字面量-->
<bean id="book1" class="com.atguigu.spring5.Book">
<property name="bname" value="字面量null"></property>
<property name="bauthor">
<null></null>
</property>
</bean>
(2)測試
@Test
public void testnull(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean2.xml");
//2獲取配置建立的物件
Book book1 = context.getBean ("book1",Book.class);
System.out.println (book1);
}
(3)結果
2、字面量,屬性值包含特殊符號
<!--5字面量,屬性值包含特殊屬性-->
<bean id="book2" class="com.atguigu.spring5.Book">
<property name="bname" value="字面量包含特殊值"></property>
<property name="bauthor">
<value><![CDATA[<<哈哈哈>>]]></value>
</property>
</bean>
(2)測試
@Test
public void testteshu(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean2.xml");
//2獲取配置建立的物件
Book book2 = context.getBean ("book2",Book.class);
System.out.println (book2);
}
(3)結果
2、注入屬性-外部 bean
(1)建立兩個類 service 類和 dao 類
package com.atguigu.spring5.dao;
public interface UserDao {
public void update();
}
package com.atguigu.spring5.dao;
public class UserDaoImp implements UserDao {
@Override
public void update() {
System.out.println ("update...");
}
}
(2)在 service 呼叫 dao 裡面的方法
package com.atguigu.spring5.service;
import com.atguigu.spring5.dao.UserDao;
public class UserService {
private UserDao userDao;
public void setUserDao(UserDao userDao) {
this.userDao = userDao;
}
public void add(){
//1建立UserDao屬性,生成set方法
System.out.println ("add...");
userDao.update ();
}
}
(3)在 spring 配置檔案中進行配置
<bean id="userService" class="com.atguigu.spring5.service.UserService">
<property name="userDao" ref="userDaoImp"></property>
</bean>
<bean id="userDaoImp" class="com.atguigu.spring5.dao.UserDaoImp"></bean>
(4)測試
@Test
public void test1(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean3.xml");
//2獲取配置建立的物件
UserService bean = context.getBean ("userService", UserService.class);
System.out.println (bean);
bean.add ();
}
(5)結果
3、注入屬性-內部 bean
(1)一對多關係:部門和員工
一個部門有多個員工,一個員工屬於一個部門,部門是一,員工是多
package com.atguigu.spring5;
public class Emp {
private String ename;
private String gender;
//員工屬於某一個部門,使用物件形式表示
private Dept dept;
public void setDept(Dept dept) {
this.dept = dept;
}
public void setEname(String ename) {
this.ename = ename;
}
public void setGender(String gender) {
this.gender = gender;
} }
package com.atguigu.spring5;
public class Dept {
private String dname;
public void setDname(String dname) {
this.dname = dname;
}
}
(2)在實體類之間表示一對多關係,員工表示所屬部門,使用物件型別屬性進行表示
(3)在 spring 配置檔案中進行配置
<bean id="userDaoImp" class="com.atguigu.spring5.dao.UserDaoImp"></bean>
<bean id="emp" class="com.atguigu.spring5.Emp">
<property name="ename" value="dd"></property>
<property name="gender" value="男"></property>
<property name="dept">
<bean id="dept" class="com.atguigu.spring5.Dept">
<property name="dname" value="保安部門"></property>
</bean>
</property>
</bean>
(4)測試
@Test
public void test2(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean3.xml");
//2獲取配置建立的物件
Emp emp = context.getBean ("emp", Emp.class);
System.out.println (emp);
}
(5)結果
4、xml 注入集合屬性
1、注入陣列型別屬性
2、注入 List 集合型別屬性
3、注入 Map 集合型別屬性
(1)建立類,定義陣列、list、map、set 型別屬性,生成對應 set 方法
package com.atguigu.spring5;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class Stu {
//1 陣列型別屬性
private String[] courses;
//2 list 集合型別屬性
private List<String> list;
//3 map 集合型別屬性
private Map<String, String> maps;
//4 set 集合型別屬性
private Set<String> sets;
public void setSets(Set<String> sets) {
this.sets = sets;
}
public void setCourses(String[] courses) {
this.courses = courses;
}
public void setList(List<String> list) {
this.list = list;
}
public void setMaps(Map<String, String> maps) {
this.maps = maps;
}
}
(2)在 spring 配置檔案進行配置
<!--注入集合型別-->
<bean id="stu" class="com.atguigu.spring5.Stu">
<property name="courses">
<array>
<value>java</value>
<value>php</value>
</array>
</property>
<property name="list">
<list>
<value>張三</value>
<value>王五</value>
</list>
</property>
<property name="maps">
<map>
<entry key="java" value="JAVA"></entry>
<entry key="K1" value="V1"></entry>
</map>
</property>
<property name="sets">
<set>
<value>1</value>
<value>2</value>
</set>
</property>
</bean>
(3)測試
@Test
public void test3(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean3.xml");
//2獲取配置建立的物件
Stu stu = context.getBean ("stu", Stu.class);
System.out.println (stu);
}
(4)結果
4、在集合裡面設定物件型別值
(1)建立課程和課程List
package com.atguigu.spring5;
public class Course {
private String cname;
public void setCname(String cname) {
this.cname = cname;
}
@Override
public String toString() {
return "Course{" +
"cname='" + cname + '\'' +
'}';
}
}
package com.atguigu.spring5;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Set;
public class Stu {
//1 陣列型別屬性
private String[] courses;
//2 list 集合型別屬性
private List<String> list;
//3 map 集合型別屬性
private Map<String, String> maps;
//4 set 集合型別屬性
private Set<String> sets;
//5學生學的多門課程
private List<Course> courseList;
@Override
public String toString() {
return "Stu{" +
"courses=" + Arrays.toString (courses) +
", list=" + list +
", maps=" + maps +
", sets=" + sets +
", courseList=" + courseList +
'}';
}
public void setCourseList(List<Course> courseList) {
this.courseList = courseList;
}
public void setSets(Set<String> sets) {
this.sets = sets;
}
public void setCourses(String[] courses) {
this.courses = courses;
}
public void setList(List<String> list) {
this.list = list;
}
public void setMaps(Map<String, String> maps) {
this.maps = maps;
}
}
(2)配置xml檔案
<!--注入集合型別-->
<bean id="stu" class="com.atguigu.spring5.Stu">
<property name="courses">
<array>
<value>java</value>
<value>php</value>
</array>
</property>
<property name="list">
<list>
<value>張三</value>
<value>王五</value>
</list>
</property>
<property name="maps">
<map>
<entry key="java" value="JAVA"></entry>
<entry key="K1" value="V1"></entry>
</map>
</property>
<property name="sets">
<set>
<value>1</value>
<value>2</value>
</set>
</property>
<!--集合中的物件注入-->
<property name="courseList">
<list>
<ref bean="c1"></ref>
<ref bean="c2"></ref>
</list>
</property>
</bean>
<bean id="c1" class="com.atguigu.spring5.Course">
<property name="cname" value="資料庫課程"></property>
</bean>
<bean id="c2" class="com.atguigu.spring5.Course">
<property name="cname" value="java課程"></property>
</bean>
(3)測試
@Test
public void test3(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean3.xml");
//2獲取配置建立的物件
Stu stu = context.getBean ("stu", Stu.class);
System.out.println (stu);
}
(4)結果
5、把集合注入部分提取出來
(1)在 spring 配置檔案中引入名稱空間 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/util/spring-util.xsd">
<!--util標籤抽取list集合型別的注入-->
<util:list id="bookList">
<value>易筋經</value>
<value>九陰真經</value>
<value>九陽神功</value>
</util:list>
<!--2 提取 list 集合型別屬性注入使用-->
<bean id="b" class="com.atguigu.spring5.util.Books">
<property name="list" ref="bookList"></property>
</bean>
(2) Books類,與前面的book不一樣。
package com.atguigu.spring5.util;
import java.util.List;
public class Books {
private List<String> list;
public void setList(List<String> list) {
this.list = list;
}
}
(3)測試
@Test
public void test4(){
//1載入Spring配置檔案
ApplicationContext context = new ClassPathXmlApplicationContext ("bean3.xml");
//2獲取配置建立的物件
Books b = context.getBean ("b", Books.class);
System.out.println (b);
}
(4)結果