springBean参数注入的几个方法

1、普通方式注入

applicationContext.xml

<?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">

    <bean id="person" class="com.xiaostudy.service.PersonImple">
        <property name="id" value="2018"></property>
        <property name="name" value="xiaostudy"></property>
        <property name="age" value="23"></property>
    </bean>
</beans>

PersonImple.java

package com.xiaostudy.service;

public class PersonImple implements Person {

    private Integer id;
    private String name;
    private Integer age;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    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;
    }

    @Override
    public String toString() {
        return "PersonImple [id=" + id + ", name=" + name + ", age=" + age + "]";
    }

}

2、通过构造方法的注入，name为参数名称

applicationContext.xml

<?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">

    <bean id="person" class="com.xiaostudy.service.PersonImple">
        <constructor-arg name="id" value="2018"></constructor-arg>
        <constructor-arg name="name" value="xiaostudy"></constructor-arg>
        <constructor-arg name="age" value="23"></constructor-arg>
    </bean>
</beans>

PersonImple.java

package com.xiaostudy.service;

public class PersonImple implements Person {

    private Integer id;
    private String name;
    private Integer age;

    public PersonImple(Integer id, String name, Integer age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    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;
    }

    @Override
    public String toString() {
        return "PersonImple [id=" + id + ", name=" + name + ", age=" + age + "]";
    }

}

3、也是通过构造方法注入，index为参数索引的位置

applicationContext.xml

<?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">

    <bean id="person" class="com.xiaostudy.service.PersonImple">
        <constructor-arg index="0" value="2018"></constructor-arg>
        <constructor-arg index="1" value="xiaostudy"></constructor-arg>
        <constructor-arg index="2" value="23"></constructor-arg>
    </bean>
</beans>

4、也是通过构造方法注入，type是参数的数据类型

applicationContext.xml

<?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">

    <bean id="person" class="com.xiaostudy.service.PersonImple">
        <constructor-arg type="java.lang.Integer" value="2018" index="0"></constructor-arg>
        <constructor-arg type="java.lang.String" value="xiaostudy" index="1"></constructor-arg>
        <constructor-arg type="java.lang.Integer" value="23" index="2"></constructor-arg>
    </bean>
</beans>

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