属性依赖注入

基于xml装配：

构造方法注入

1目标类

package com.itheima.f_xml.a_construct;public class User {private Integer uid ;private String username ;private Integer age ;public User(Integer uid, String username) {super();this.uid = uid;this.username = username;}public User(String username, Integer age) {super();this.username = username;this.age = age;}public Integer getUid() {return uid;}public void setUid(Integer uid) {this.uid = uid;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}@Overridepublic String toString() {return "User [uid=" + uid + ", username=" + username + ", age=" + age+ "]";}}

2spring配置

<!-- 配置service <bean> 配置需要创建的对象id ：用于之后从spring容器获得实例时使用的class ：需要创建实例的全限定类名构造方法注入：<consturctor-arg> 用于配置构造方法中一个参数argumentindex:参数的索引号，从0开始，如果只有索引，匹配到多个构造方法时，默认使用第一个。type : 确定参数类型 --><bean id="userId" class="com.itheima.f_xml.a_construct.User">    <constructor-arg index="0" type="java.lang.String" value="1"></constructor-arg>    <constructor-arg index="1"  type="java.lang.Integer" value="2"></constructor-arg></bean>

3测试

package com.itheima.f_xml.a_construct;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;public class TestCon {@Testpublic void demo02(){String xmlPath = "com/itheima/f_xml/a_construct/beans.xml";ApplicationContext applicationContext = new ClassPathXmlApplicationContext(xmlPath);User user= (User) applicationContext.getBean("userId");System.out.println(user);}
}

setter方法注入

1目标类

package com.itheima.f_xml.b_setter;public class Person {private String name ;private Integer age ;private Address homeaddr ;private Address companyaddr ;public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Address getHomeaddr() {return homeaddr;}public void setHomeaddr(Address homeaddr) {this.homeaddr = homeaddr;}public Address getCompanyaddr() {return companyaddr;}public void setCompanyaddr(Address companyaddr) {this.companyaddr = companyaddr;}@Overridepublic String toString() {return "Person [name=" + name + ", age=" + age + ", homeaddr="+ homeaddr + ", companyaddr=" + companyaddr + "]";}}

package com.itheima.f_xml.b_setter;public class Address {private String addr ;private String tel ;public String getAddr() {return addr;}public void setAddr(String addr) {this.addr = addr;}public String getTel() {return tel;}public void setTel(String tel) {this.tel = tel;}@Overridepublic String toString() {return "Address [addr=" + addr + ", tel=" + tel + "]";}}

2配置

<!-- setter方法注入     property   --><bean id = "personid" class="com.itheima.f_xml.b_setter.Person">    <property name="name" value = "**"></property><property name="age" value="27"></property><property name="homeaddr" ref="homeAddrId"></property><property name="companyaddr" ref="companyAddrId"></property></bean><bean id = "homeAddrId" class="com.itheima.f_xml.b_setter.Address">    <property name="addr" value="湖北"></property>    <property name="tel" value="158"></property></bean><bean id="companyAddrId" class="com.itheima.f_xml.b_setter.Address">    <property name="addr" value="上海"></property>    <property name="tel" value="159"></property></bean>

3测试

p命令空间方法注入

该方法是对setter方法进行简化，替换<property>，而是在<bean  p:属性名= “普通数据 ” p:属性名-ref = "引用数据">

<bean id = "personid"  class="com.itheima.f_xml.b_setter.Person"     p:name = "zn" p:age="27"     p:homeaddr-ref="homeAddrId"    p:companyaddr-ref= "companyAddrId"></bean><bean id = "homeAddrId" class="com.itheima.f_xml.b_setter.Address"    p:addr = "湖北" p:tel = "111"></bean><bean id="companyAddrId" class="com.itheima.f_xml.b_setter.Address"    p:addr = "sh" p:tel = "123"></bean>

SpEL注入

对<property>进行统一编程，所有的内容都使用value

<!-- <property name="name" value="#{'jack'}"></property>    <property name="name" value="#{personId.name.toUpperCase()}"></property>    通过另一个bean，获得属性，调用方法    <property name="name" value="#{personId.name?.toUpperCase()}"></property>    ?.如果对象不为null，将调用方法     <property name="pi" value="#{T(java.lang.Math).PI}"></property>           静态类的字段 --><bean id="personId" class = "com.itheima.f_xml.c_spEL.Person" >        <property name="name" value="#{personId.name?.toUpperCase()}"></property>    <property name="pi" value="#{T(java.lang.Math).PI}"></property></bean>

集合注入

        <!-- 集合的注入都是给<property>添加子标签           数组：标签<array>    List: <list>    Set:<set>    Map:<map> map存k/v键值对，用entry    Properties: <props> <prop key="">value</prop>    普通数据： 标签<value>    引用数据：<ref>             --><bean id="personId" class = "com.itheima.f_xml.c_spEL.Person" ><property name="arrayData">    <array>        <value>dd</value>        <value>dd1</value>        <value>dd2</value>        <value>dd3</value>    </array></property><property name="listData">    <list>        <value>list1</value>        <value>list2</value>        <value>list3</value>        <value>list4</value>            </list></property><property name="setData">    <set>        <value>set1</value>        <value>set2</value>          </set></property><property name="mapData">    <map>        <entry key="map" value="地图"></entry>         <entry key="jack" value="捷克"></entry>            </map></property><property name="propsData">    <props>        <prop key="高富帅">洋</prop>        <prop key="白富美">美</prop>        <prop key="屌丝">周</prop>    </props></property></bean>