Spring的Setter注入（简单数据类型、引用数据类型、集合数据类型）

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本文详细介绍了Spring框架中Setter注入的使用，包括如何配置XML以实现简单数据类型、引用数据类型和集合数据类型的注入。针对不同类型的属性，如八大基本类型、String、BigDecimal、Date等，可以使用`value`标签注入；对于引用数据类型，使用`ref`标签进行注入；而对于集合数据类型，如List、Set等，需要利用集合元素进行注入。

Setter注入:最常用的注入方法,需要在xml配置文件中进行手动的配置.

要求:
对象中的每个属性必须要有setter 方法

如何配置:
需要为对象中的每个属性配置一个"property"标签:

<property name="" />

其中name属性的值为对象中属性的名字.如何给属性注入值时,需要先确定该属性的类型

对象中的属性分为以下三种类型,不同的类型使用不同的注入方式
1):简单数据类型(八大基本类型,String,BigDecimal,Date等). 使用value.
2):引用数据类型. 使用ref.
3):集合数据类型. 使用集合的元素.

代码：
pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>text</groupId>
    <artifactId>Spring02</artifactId>
    <version>1.0.0</version>
    <packaging>jar</packaging>


    <properties>
        <!--
            定义全局变量:变量名为project.spring.version
        -->
        <project.spring.version>5.0.0.RELEASE</project.spring.version>

    </properties>


    <dependencies>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>


        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-expression</artifactId>
            <version>${project.spring.version}</version>
        </dependency>


        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${project.spring.version}</version>
        </dependency>

    </dependencies>

    <build>

        <!--加载资源文件-->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
            </resource>

            <resource>
                <directory>src/main/resources</directory>
                <includes>
                    <include>**/*.xml</include>
                    <include>**/*.properties</include>
                </includes>
            </resource>
        </resources>


    </build>

</project>

App-context.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">




    <!--集合数据类型,使用property标签,在双标签中使用各个集合对应的标签-->
    <bean id="collectionBean" class="text.spring._01_setter.CollectionBean">
        <property name="set">
            <set>
               <value>set1</value>
               <value>18</value>
               <value>1000</value>
                <ref bean="person"></ref>
            </set>
        </property>


        <property name="list">
            <list>
                <value>list1</value>
                <value>list2</value>
                <value>list3</value>
            </list>
        </property>


        <property name="array">
            <array>
                <value>array1</value>
                <value>array2</value>
                <value>array3</value>
            </array>

        </property>

        <property name="map">
            <map>
                <entry key="k1" value="v1"></entry>
                <entry key="k2" value="v2"></entry>
                <entry key="k3" value="v3"></entry>
                <!--<entry key="k4" value-ref="person"></entry>-->
            </map>
        </property>

        <property name="prop">
            <props>
                <prop key="p1">v1</prop>
                <prop key="p2">v2</prop>
            </props>
        </property>

    </bean>


    <!--引用数据类型,使用ref引用当前容器当中的对象-->
    <bean id="dog" class="text.spring._01_setter.Dog">
        <property name="name" value="汪汪"/>
    </bean>
    <!--ref:引用当前容器当中的bean-->
    <bean id="person" class="text.spring._01_setter.Person">
        <property name="dog" ref="dog"/>
    </bean>


    <!--简单数据类型-->
    <bean id="employee" class="text.spring._01_setter.Employee">
        <!--
            setter方式注入,本质是在执行对象中的set方法
            Spring容器在注入值时,隐含着类型转换
        -->
        <property name="name" value="rose"/>
        <property name="age" value="20"/>
        <property name="birthday" value="2019/09/03"/>
        <property name="salary" value="1000"/>

    </bean>

</beans>

App.java：

package text.spring._01_setter;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

/**
 * Created by thinkpad on 2019/9/3.
 */
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration
public class App {


   @Autowired
   private Employee employee;


   @Autowired
   private Person person;


   @Autowired
   private CollectionBean collectionBean;


    @Test
    public void testEmployee() throws Exception {

        System.out.println(employee);
    }


    @Test
    public void testPerson() throws Exception {
        System.out.println(person);
    }


    @Test
    public void testCollectionBean() throws Exception {
        System.out.println(collectionBean);
    }
}

简单数据类型：
Employee.java：

package text.spring._01_setter;

import java.math.BigDecimal;
import java.util.Date;

/**
 * Created by thinkpad on 2019/9/3.
 */

public class Employee {


    private String name;

    private Integer age;

    private Date birthday;

    private BigDecimal salary;


    public void setName(String name) {
        this.name = name;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public void setSalary(BigDecimal salary) {
        this.salary = salary;
    }

    public String toString() {
        return "Employee{" +
                "name='" + name + '\'' +
                ", age=" + age +
                ", birthday=" + birthday +
                ", salary=" + salary +
                '}';
    }
}

引用数据类型：
Person.java：

package text.spring._01_setter;

/**
 * Created by thinkpad on 2019/9/3.
 */
public class Person {


    private Dog dog;


    public void setDog(Dog dog) {
        this.dog = dog;
    }

    public String toString() {
        return "Person{" +
                "dog=" + dog +
                '}';
    }
}

Dog.java：

package text.spring._01_setter;

/**
 * Created by thinkpad on 2019/9/3.
 */
public class Dog {

    private String name;

    public void setName(String name) {
        this.name = name;
    }


    @Override
    public String toString() {
        return "Dog{" +
                "name='" + name + '\'' +
                '}';
    }
}

集合数据类型：
CollectionBean.java：

package text.spring._01_setter;

import java.util.*;

/**
 * Created by thinkpad on 2019/9/3.
 */
public class CollectionBean {


    private Set set;

    private List<String> list;

    private String[] array;

    private Map<String, String> map;

    private Properties prop;


    public void setSet(Set set) {
        this.set = set;
    }

    public void setList(List<String> list) {
        this.list = list;
    }

    public void setArray(String[] array) {
        this.array = array;
    }

    public void setMap(Map<String, String> map) {
        this.map = map;
    }

    public void setProp(Properties prop) {
        this.prop = prop;
    }


    @Override
    public String toString() {
        return "CollectionBean{" +
                "set=" + set +
                ", list=" + list +
                ", array=" + Arrays.toString(array) +
                ", map=" + map +
                ", prop=" + prop +
                '}';
    }
}