Spring中几种构造方法实例化的方法

1、基本数据类型或String 使用value属性赋值

<bean class="com.jd.vo.Student">
    <constructor-arg value="12"></constructor-arg>
    <constructor-arg value="Jim"></constructor-arg>
</bean>

2、类类型,则使用ref属性赋值

<bean class="com.jd.vo.Student">
    <constructor-arg ref="date"></constructor-arg>
</bean>

3、List 则使用list标签

    <bean id="n" class="java.lang.String">
         <constructor-arg value="黄林"></constructor-arg>
    </bean>
    <bean class="com.jd.vo.Student">
        <constructor-arg>
            <list>
                <value>张三</value>
                <value>李四</value>
                <bean class="java.lang.String">
                    <constructor-arg value="王五"></constructor-arg>
                </bean>
                <ref bean="n"></ref>
            </list>
        </constructor-arg>
    </bean>

4、array 则使用array标签

    <bean name="s" class="java.lang.Integer">
        <constructor-arg value="100"></constructor-arg>
    </bean>
    <bean class="com.jd.vo.Student">
        <constructor-arg>
            <array>
                <value>70</value>
                <bean class="java.lang.Integer">
                    <constructor-arg value="90"></constructor-arg>
                </bean>
                <ref bean="s"></ref>
            </array>
        </constructor-arg>
    </bean>

5、set 则使用set标签

    <bean name="t" class="java.lang.String">
        <constructor-arg value="119"></constructor-arg>
    </bean>
    <bean class="com.jd.vo.Student">
        <constructor-arg>
            <set>
                <value>70</value>
                <bean class="java.lang.String">
                    <constructor-arg value="190"></constructor-arg>
                </bean>
                <ref bean="t"></ref>
            </set>
        </constructor-arg>
    </bean>

6、map 则使用map标签

    <bean name="k" class="java.lang.String">
        <constructor-arg value="ljj"></constructor-arg>
    </bean>
    <bean name="v" class="java.lang.String">
        <constructor-arg value="119"></constructor-arg>
    </bean>
    <bean class="com.jd.vo.Student">
        <constructor-arg>
            <map>
                <entry key="Jim" value="90"></entry>
                <entry key-ref="k" value-ref="v"></entry>
            </map>
        </constructor-arg>
    </bean>

7、properties 则使用props标签

    <bean class="com.jd.vo.Student">
        <constructor-arg>
            <props>
               <prop key="name">Jim</prop>
                <prop key="mobile">789</prop>
            </props>
        </constructor-arg>
    </bean>

    <bean id="s" class="java.lang.Integer">
        <constructor-arg value="100"></constructor-arg>
    </bean>
    <bean class="com.jd.vo.Student">
        <property name="name" value="Jim"></property>
        <property name="scores">
            <array>
                <value>120</value>
                <bean class="java.lang.Integer">
                    <constructor-arg value="90"></constructor-arg>
                </bean>
                <ref bean="s"></ref>
            </array>
        </property>
    </bean>

Test中执行即可得到结果

import com.jd.vo.Student;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.Date;

public class Test {

    public static void main(String[] args) {
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("application.xml");
        /*Date date = applicationContext.getBean(Date.class);
        System.out.println(date);*/

        /*Object object = applicationContext.getBean("ddd");
        System.out.println(object);*/

        applicationContext.close();//关闭applicationContext
    }
}

本文地址：https://blog.csdn.net/m0_46383618/article/details/109276488