Spring之三种依赖注入，给各种集合类型的属性注入值

Z时代
2024-01-10
分类：综合

本文内容纲要：Spring之三种依赖注入，给各种集合类型的属性注入值

一、第一种注入（set注入）：

创建实体类,Teacher:

package org.ruangong.entity;
public class Teacher {
	private String name;
	private int age;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
}

　　创建实体类，Course:

package org.ruangong.entity;
public class Course {
	private String cname;
	private int chour;
	private Teacher teacher;
	public String getCname() {
		return cname;
	}
	public void setCname(String cname) {
		this.cname = cname;
	}
	public int getChour() {
		return chour;
	}
	public void setChour(int chour) {
		this.chour = chour;
	}
	public Teacher getTeacher() {
		return teacher;
	}
	public void setTeacher(Teacher teacher) {
		this.teacher = teacher;
	}
	@Override
	public String toString() {
		return "Course [cname=" + cname + ", chour=" + chour + ", teacher=" + teacher.getName() + teacher.getAge()+"]";
	}
}

　　在applicationContext.xml文件中添加bean标签。

<bean id="teacher" class="org.ruangong.entity.Teacher">
		<property name="name" value="王建民"></property>
		<property name="age" value="50"></property>		
	</bean>
	<bean id="course" class="org.ruangong.entity.Course">
		<property name="cname" value="java"></property>
		<property name="chour" value="2"></property>
		<property name="teacher" ref="teacher"></property>
	</bean>

　　其中的ref=“”，对应对象值。将teacher对象注入到course对象中。

二、第二中注入(构造器注入)：

在Teacher实体中添加构造方法。

public Teacher(String name, int age) {
		super();
		this.name = name;
		this.age = age;
	}

　　在Course实体中添加构造方法：

public Course(String cname, int chour, Teacher teacher) {
		super();
		this.cname = cname;
		this.chour = chour;
		this.teacher = teacher;
	}

　　在之前的applicationContext.xml文件的id为teacher和course标签重新添加构造方法。

<bean id="teacher" class="org.ruangong.entity.Teacher">
	<!-- 通过set注入 -->
		<!-- <property name="name" value="王建民"></property>
		<property name="age" value="50"></property>	 -->
	<!-- 通过构造器注入 -->
		<constructor-arg value="刘丹"></constructor-arg>
		<constructor-arg value="48"></constructor-arg>
	</bean>
	<bean id="course" class="org.ruangong.entity.Course">
	<!-- 通过set注入 -->
		<!-- <property name="cname" value="java"></property>
		<property name="chour" value="2"></property>		
		<property name="teacher" ref="teacher"></property> -->
	<!-- 通过构造器注入 -->
		<constructor-arg value="PHP"></constructor-arg>
		<constructor-arg value="5"></constructor-arg>
		<constructor-arg ref="teacher"></constructor-arg>
	</bean>

　　的value顺序和构造方法的属性值严格一致。

或者可以在constructor标签的后面添加index="key",key值来控制属性顺序。

或者添加name="key"，key来控制属性名。

三、第三种注入（P值注入）

生成P的标签。

<bean id="teacher" class="org.ruangong.entity.Teacher" p:name="刘立嘉" p:age="60">
	<!-- 通过set注入 -->
		<!-- <property name="name" value="王建民"></property>
		<property name="age" value="50"></property>	 -->
	<!-- 通过构造器注入 -->
		<!-- <constructor-arg value="刘丹"></constructor-arg>
		<constructor-arg value="48"></constructor-arg> -->
	</bean>
	<bean id="course" class="org.ruangong.entity.Course" p:cname="统一建模" p:chour="6" p:teacher-ref="teacher">
	<!-- 通过set注入 -->
		<!-- <property name="cname" value="java"></property>
		<property name="chour" value="2"></property>		
		<property name="teacher" ref="teacher"></property> -->
	<!-- 通过构造器注入 -->
		<!-- <constructor-arg value="PHP"></constructor-arg>
		<constructor-arg value="5"></constructor-arg>
		<constructor-arg ref="teacher"></constructor-arg> -->
	</bean>

　　四、集合类型值注入：

创建集合实体，AllCollectionType:

package org.ruangong.entity;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
public class AllCollectionType {
	private List<String> list;
	private String[] array;
	private Map<String,String> map;
	private Set<String> set;
	private Properties props;
	public List<String> getList() {
		return list;
	}
	public void setList(List<String> list) {
		this.list = list;
	}
	public String[] getArray() {
		return array;
	}
	public void setArray(String[] array) {
		this.array = array;
	}
	public Map<String, String> getMap() {
		return map;
	}
	public void setMap(Map<String, String> map) {
		this.map = map;
	}
	public Set<String> getSet() {
		return set;
	}
	public void setSet(Set<String> set) {
		this.set = set;
	}
	public Properties getProps() {
		return props;
	}
	public void setProps(Properties props) {
		this.props = props;
	}
	@Override
	public String toString() {
		return "AllCollectionType [list=" + list + ", array=" + Arrays.toString(array) + ", map=" + map + ", set=" + set
				+ ", props=" + props + "]";
	}
}

　　在applicationContext.xml文件中：

<bean id="collection" class="org.ruangong.entity.AllCollectionType">
	<!-- 通过set方式赋值 -->
	<property name="list">
		<list>
			<value>篮球</value>
			<value>足球</value>
			<value>乒乓球</value>
		</list>
	</property>
	<property name="array">
		<array>
			<value>篮球_array</value>
			<value>足球_array</value>	
			<value>乒乓球_array</value>	
		</array>
	</property>
	<property name="map">
			<map>
				<entry>
					<key>
					 	<value>
					 	foot
					 	</value>
					</key>
					<value>足球</value>
					</entry>
					<entry>
					<key>
					 	<value>
					 	basket
					 	</value>
					</key>
					<value>篮球球</value>
					</entry>
					<entry>
					<key>
					 	<value>
					 	pingpang
					 	</value>
					</key>
					<value>足球</value>
				</entry>
			</map>
	</property>
	<property name="set">
		<set>
			<value>篮球_set</value>
			<value>足球_set</value>	
			<value>乒乓球_set</value>	
		</set>
	</property>
	<property name="props">
		<props>
			<prop key="foot4">足球</prop>
			<prop key="basket4">篮球</prop>		
			<prop key="pp4">乒乓球</prop>
		</props>
	</property>
	</bean>

　　test中进行测试：

public static void collectionDemo(){
		ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
		AllCollectionType type = (AllCollectionType)context.getBean("collection");
		System.out.println(type);
	}