p命名空间简化属性依赖注入之setter方法

Posted 2020-07-07 时间沉淀美好

 为了简化setter方法，之前通过<property>进行注入，p命名使用属性，<bean id="" class=""  p:属性名="普通值"  p:属性名-ref="引用值">。不过这种方法在企业级开发中用的比较少。

如图所示，在实现p命名空间之前，要做一点事情。前面p必选，后面p可以改成别的名字。

来两份Bean

public class address 
{
	private String name;
	private String tel;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getTel() {
		return tel;
	}
	public void setTel(String tel) {
		this.tel = tel;
	}
	@Override
	public String toString() {
		return "address [name=" + name + ", tel=" + tel + "]";
	}
}

public class person 
{
	private String name;
	private address homeAddress;
	private address companyAddress;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public address getHomeAddress() {
		return homeAddress;
	}
	public void setHomeAddress(address homeAddress) {
		this.homeAddress = homeAddress;
	}
	public address getCompanyAddress() {
		return companyAddress;
	}
	public void setCompanyAddress(address companyAddress) {
		this.companyAddress = companyAddress;
	}
	@Override
	public String toString() {
		return "person [name=" + name + ", homeAddress=" + homeAddress
				+ ", companyAddress=" + companyAddress + "]";
	}
	
}

我们重点关注xml配置。

<!-- 
	p命名空间
	企业级开发用的比较少 
	-->
	<bean id="homeaddressID" class="com.canyugan.setter.address"
		  p:name="中环村"
		  p:tel="1816604">
	</bean>
	<bean id="companyaddressID" class="com.canyugan.setter.address"
		  p:name="北京天安门"
		  p:tel="123456">
	</bean>
	<bean id="personID" 
		  class="com.canyugan.setter.person" 
		  p:name="参与感"
		  p:homeAddress-ref="homeaddressID"
		  p:companyAddress-ref="companyaddressID">
    </bean>

对比不使用p命名空间的配置方法：

	<bean id="homeaddressID" class="com.canyugan.setter.address">
		<property name="name" value="中关村"></property>
		<property name="tel" value="1816604"></property>
	</bean>
	<bean id="companyaddressID" class="com.canyugan.setter.address">
		<property name="name" value="北京天安门"></property>
		<property name="tel" value="123456"></property>
	</bean>
	<bean id="personID" class="com.canyugan.setter.person">
		<property name="name" value="参与感"/>
		<property name="homeAddress" ref="homeaddressID"/>
		<property name="companyAddress" ref="companyaddressID"/>
	</bean>

是不是看不出来有什么优化？对，企业级开发用的少，有些技术狂人就是喜欢倒腾你不会的东西，所以，我们知道有这个东西就可以。