Spring學習（1）--使用xml配置Bean屬性
阿新 • • 發佈：2019-02-15
使用xml配置Bean屬性之前需要先定義對應的XML和對應xsd檔案：
<?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">
依賴注入主要有三種方式：
1.setter注入
2.構造器注入
3.介面注入
由於介面注入使用很少，這裡主要寫下前面兩種注入屬性的方式。
1.使用setter方式
Java檔案程式碼：
package com.study.beans; public class HelloWorld { private String name; public void setName(String name) { System.out.println("setName()"+name); this.name = name; } public HelloWorld(){ System.out.println("HelloWorld的無參構造器"); } public void hello(){ System.out.println("hello"+name); } }
xml檔案程式碼：
<!--setter方式屬性注入 -->
<bean id="helloWorld" class="com.study.beans.HelloWorld">
<property name="name" value="zhang"></property>
</bean>測試程式碼：
測試結果：public class TestDemo { @Test public void test(){ //1.載入spring配置檔案，根據配置建立物件 //ClassPathXmlApplicationContext是ApplicationContext介面的實現類，該類從類路徑下載入配置檔案 ApplicationContext app=new ClassPathXmlApplicationContext("applicationContext.xml"); //2.獲取Bean HelloWorld helloWorld=(HelloWorld) app.getBean("helloWorld"); System.out.println(helloWorld); } }
HelloWorld的無參構造器
setName()zhang2.使用構造器方式
Java檔案程式碼：
package com.study.beans;
public class CarDemo {
private String brand;
private String corp;
private double price;
private int maxSpeed;
public void setMaxSpeed(int maxSpeed) {
this.maxSpeed = maxSpeed;
}
public CarDemo(String brand, String corp, double price) {
super();
this.brand = brand;
this.corp = corp;
this.price = price;
}
public CarDemo(String brand, String corp, int maxSpeed) {
super();
this.brand = brand;
this.corp = corp;
this.maxSpeed = maxSpeed;
}
public CarDemo(String brand, String corp, double price, int maxSpeed) {
super();
this.brand = brand;
this.corp = corp;
this.price = price;
this.maxSpeed = maxSpeed;
}
@Override
public String toString() {
return "CarDemo [brand=" + brand + ", corp=" + corp + ", price="
+ price + ", maxSpeed=" + maxSpeed + "]";
}
}
xml檔案程式碼：
<!--構造器方式屬性注入 -->
<bean id="carDemo" class="com.study.beans.CarDemo">
<constructor-arg value="BMW"></constructor-arg>
<constructor-arg value="HEFEI"></constructor-arg>
<constructor-arg value="6900"></constructor-arg>
</bean>xml檔案程式碼：
<!--特殊字元可以使用<!CDATA[xxx]>方式注入 -->
<bean id="carDemo1" class="com.study.beans.CarDemo">
<constructor-arg index="0" type="String">
<value><![CDATA[<DGDG>]]></value>
</constructor-arg>
<constructor-arg index="1" type="String">
<value>822</value>
</constructor-arg>
<constructor-arg value="6900" index="2" type="int"></constructor-arg>
</bean>CarDemo [brand=<DGDG>, corp=822, price=0.0, maxSpeed=6900]<!-- null值使用<null/>注入 -->
<bean id="carDemo2" class="com.study.beans.CarDemo">
<constructor-arg value="Bmw" index="0" type="String"></constructor-arg>
<constructor-arg>
<null/>
</constructor-arg>
<constructor-arg >
<value>822.0</value>
</constructor-arg>
</bean>java檔案程式碼：
package com.study.beans;
public class Person {
private String name;
private int age;
private CarDemo car;
public void setName(String name) {
this.name = name;
}
public void setAge(int age) {
this.age = age;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
public CarDemo getCar() {
return car;
}
public void setCar(CarDemo car) {
this.car = car;
}
public Person() {
}
public Person(String name, int age, CarDemo car) {
super();
this.name = name;
this.age = age;
this.car = car;
}
@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + ", car=" + car + "]";
}
}
xml檔案程式碼：
<!-- 使用ref引用其他Bean -->
<bean id="person1" class="com.study.beans.Person">
<property name="name" value="zhangshiwei"></property>
<property name="age" value="23"></property>
<property name="car" ref="carDemo2"></property>
</bean>6.使用內部Bean
<!-- 內部Bean，只能在內部使用，不能被外部引用 -->
<bean id="person2" class="com.study.beans.Person">
<property name="name" value="zhangshiwei"></property>
<property name="age" value="23"></property>
<property name="car">
<bean class="com.study.beans.CarDemo">
<constructor-arg value="Bmw" index="0" type="String"></constructor-arg>
<constructor-arg><null/></constructor-arg>
<constructor-arg >
<value>822.0</value>
</constructor-arg>
</bean>
</property>
</bean>7.為級聯屬性賦值
<!--為級聯屬性賦值 -->
<bean id="person3" class="com.study.beans.Person">
<constructor-arg name="name" value="zhangshiwei"></constructor-arg>
<constructor-arg name="age" value="23"></constructor-arg>
<constructor-arg name="car" ref="carDemo2"></constructor-arg>
<property name="car.maxSpeed" value="444"></property>
</bean>上面程式碼中必須先初始化id為car的Bean，否則報錯
8.為list集合屬性賦值將person類中的car屬性改為：
public class PersonListCar {
private String name;
private int age;
private List<CarDemo> cars;<!--為list集合屬性賦值 --> <bean id="personListCar" class="com.study.beans.PersonListCar"> <constructor-arg name="name" value="zhangshiwei"></constructor-arg> <constructor-arg name="age" value="23"></constructor-arg> <constructor-arg name="cars"> <list> <ref bean="carDemo"/> <ref bean="carDemo1"/> <ref bean="carDemo2"/> </list> </constructor-arg> </bean>測試結果：
PersonListCar [name=zhangshiwei, age=23, cars=[CarDemo [brand=BMW, corp=HEFEI, price=0.0, maxSpeed=6900], CarDemo [brand=<DGDG>, corp=822, price=0.0, maxSpeed=6900], CarDemo [brand=Bmw, corp=null, price=822.0, maxSpeed=444]]]
如上面程式碼所示<list>節點引用了其他Bean,若注入的值是基本資料型別,寫法如下：
<list>
<value>list1</value>
<value>list2</value>
<value>list3</value>
</list>set集合和陣列型別的屬性注入方式與list集合類似，區別在與list集合使用<list>節點，set集合使用<set>節點，陣列使用<array>節點。
9.為Map型別屬性賦值將person類中的car屬性改為：
public class PersonMapCar {
private String name;
private int age;
private Map<String,CarDemo> car;<!--為Map型別屬性賦值 -->
<bean id="personMapCar" class="com.study.beans.PersonMapCar">
<constructor-arg name="name" value="zhangshiwei"></constructor-arg>
<constructor-arg name="age" value="23"></constructor-arg>
<constructor-arg name="car">
<map>
<entry key="car1" value-ref="carDemo"/>
<entry key="car2" value-ref="carDemo1"/>
<entry key="car3" value-ref="carDemo2"/>
</map>
</constructor-arg>
</bean>PersonMapCar [name=zhangshiwei, age=23, car={car1=CarDemo [brand=BMW, corp=HEFEI, price=0.0, maxSpeed=6900],
car2=CarDemo [brand=<DGDG>, corp=822, price=0.0, maxSpeed=6900], car3=CarDemo [brand=Bmw, corp=null, price=822.0, maxSpeed=444]}]10.配置Properties型別屬性值
Java檔案程式碼：
package com.study.beans;
import java.util.Properties;
public class DataSource {
private Properties properties;
public Properties getProperties() {
return properties;
}
public void setProperties(Properties properties) {
this.properties = properties;
}
@Override
public String toString() {
return "DataSource [properties=" + properties + "]";
}
}
xml檔案程式碼：
<!--配置Properties型別屬性值 -->
<bean id="dataSource" class="com.study.beans.DataSource">
<property name="properties">
<props>
<prop key="user">root</prop>
<prop key="password">root</prop>
<prop key="jdbcUrl">jdbc:mysql:///test</prop>
<prop key="driverClass">com.mysql.jdbc.Driver</prop>
</props>
</property>
</bean>DataSource [properties={driverClass=com.mysql.jdbc.Driver, user=root, password=root, jdbcUrl=jdbc:mysql:///test}]11.使用util名稱空間，配置獨立的集合Bean,可供其他Bean引用
<!-- 使用util名稱空間，配置獨立的集合Bean,可供其他Bean引用 ，需要先引入util名稱空間-->
<util:list id="car">
<ref bean="carDemo"/>
<ref bean="carDemo1"/>
<ref bean="carDemo2"/>
</util:list>
<bean id="personListCar1" class="com.study.beans.PersonListCar">
<constructor-arg name="name" value="zhangshiwei"></constructor-arg>
<constructor-arg name="age" value="23"></constructor-arg>
<constructor-arg name="cars" ref="car"></constructor-arg>
</bean>xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd">12.使用p名稱空間為Bean的屬性賦值
<!--使用p名稱空間為Bean的屬性賦值 ,需要先匯入p名稱空間-->
<bean id="personListCar2" class="com.study.beans.PersonListCar"
p:name="ZhangShiWei" p:age="23" p:cars-ref="car"></bean>xmlns:p="http://www.springframework.org/schema/p"13.使用c名稱空間注入構造引數的屬性
<!--使用c名稱空間注入構造引數的屬性 ,需要先匯入c名稱空間 -->
<bean id="personListCar3" class="com.study.beans.PersonListCar"
c:_0="ZHANGSHIwei" c:_1="23" c:_2-ref="car"></bean>引入的c名稱空間：
xmlns:c="http://www.springframework.org/schema/c"