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Spring中的集合注入代码实例

2023-11-01 10:03:45 作者：端脑

这篇文章主要介绍了Spring中的集合注入代码实例,集合注入是指在Spring框架中,通过配置文件或注解的方式将集合类型的数据注入到Bean中,集合类型包括List、Set、Map和Properties等,需要的朋友可以参考下

Spring中的集合注入

集合注入重要是对数组、List、Set、map的注入，具体注入方法请参照一下代码

重点是applicationContext.xml中对这几个集合注入的方式

代码看懂，你就会了

collection

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                http://www.springframework.org/schema/beans/spring-beans.xsd
                http://www.springframework.org/schema/context
                http://www.springframework.org/schema/context/spring-context.xsd">

    <bean id="department" class="com.chenny.entity.Department">
        <property name="name" value="财务部门" />
        <!-- 给数组注入值 -->
        <property name="empName">
            <array>
                <value>张三</value>
                <value>李四</value>
                <value>王五</value>
            </array>
        </property>

        <!-- 给list注入值 可以有相同的多个对象  -->
        <property name="empList">
            <list>
                <ref bean="emp1" />
                <ref bean="emp2"/>
                <ref bean="emp3"></ref>
            </list>
        </property>
        <!-- 给set注入值 不能有相同的对象 -->
        <property name="empSets">
            <set>
                <ref bean="emp1" />
                <ref bean="emp2"/>
                <ref bean="emp3"></ref>
            </set>
        </property>

        <!-- 给map注入值 只要map中的key值不一样就可以装配value -->
        <property name="empMap">
            <map>
                <entry key="1" value-ref="emp1" />
                <entry key="2" value-ref="emp2" />
                <entry key="3" value-ref="emp3"></entry>
            </map>
        </property>

        <!-- 给属性集合配置 -->
        <property name="pp">
            <props>
                <prop key="pp1">hello</prop>
                <prop key="pp2">world</prop>
            </props>
        </property>
    </bean>


    <bean id="emp1" class="com.chenny.entity.Employee">
        <property name="id" value="1"></property>
        <property name="name" value="张三"></property>
    </bean>
    <bean id="emp2" class="com.chenny.entity.Employee">
        <property name="id" value="2"></property>
        <property name="name" value="李四"></property>
    </bean>

    <bean id="emp3" class="com.chenny.entity.Employee">
        <property name="id" value="3"></property>
        <property name="name" value="王五"></property>
    </bean>

</beans>

Testbean

package com.chenny.test;

import com.chenny.entity.Department;
import com.chenny.entity.Employee;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;

public class TestBean {
    public static void main(String[] args) {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("collection.xml");
        Department department = (Department) applicationContext.getBean("department");
        System.out.println("*********输出全部的department的信息******");
        System.out.println(department);

        System.out.println("*********取出数组中，部门人员姓名的全部数据******");
        for(String emName : department.getEmpName()){
            System.out.println(emName);
        }
        System.out.println("*********通过List集合取出数据******");
        for(Employee e : department.getEmpList()){
            System.out.println("id" + e.getId() +"name = "+ e.getName());
        }

        System.out.println("*********通过Set集合取出数据******");
        for(Employee e : department.getEmpSets()){
            System.out.println("id = " + e.getId() +", name = "+ e.getName());
        }

        System.out.println("*********通过Map集合取出数据(迭代器方法)******");
        //迭代器
        Map<String,Employee> empMap = department.getEmpMap();
        Iterator it = empMap.keySet().iterator();
        while(it.hasNext()){
            String key = (String) it.next();
            Employee emp = empMap.get(key);
            System.out.println("key = " + key + ", id = " + emp.getId() + ", name = " + emp.getName() );
        }

        System.out.println("*********通过Map集合取出数据(Emtry简洁法)******");
        //简洁方法
        for(Map.Entry<String,Employee> entry : department.getEmpMap().entrySet()){

            System.out.println("key = " + entry.getKey()+ " id = " + entry.getValue().getId() + " name = " + entry.getValue().getName());
        }


        System.out.println("*********通过Propertis取出数据(通过Entry对象取)******");
        Properties pp = department.getPp();
        for(Map.Entry<Object,Object> entry : pp.entrySet()){
            System.out.println(entry.getKey().toString() + ", "+ entry.getValue().toString());
        }


        System.out.println("*********通过Propertis取出数据(通过Enumeration对象取)******");
        Enumeration en = pp.keys();
        while(en.hasMoreElements()){
            String key = (String) en.nextElement();
            System.out.println(key + " " + pp.getProperty(key));
        }
    }
}

Department

package com.chenny.entity;

import java.util.*;

/**
 * @author 73981
 */
public class Department {
    private String name;
    private String[] empName;
    private List<Employee> empList;
    private Set<Employee> empSets;
    private Map<String,Employee> empMap;
    private Properties pp;

    @Override
    public String toString() {
        return "Department{" +
                "name='" + name + '\'' +
                ", empName=" + Arrays.toString(empName) +
                ", empList=" + empList +
                ", empSets=" + empSets +
                ", empMap=" + empMap +
                ", pp=" + pp +
                '}';
    }

    public String getName() {
        return name;
    }

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

    public String[] getEmpName() {
        return empName;
    }

    public void setEmpName(String[] empName) {
        this.empName = empName;
    }

    public List<Employee> getEmpList() {
        return empList;
    }

    public void setEmpList(List<Employee> empList) {
        this.empList = empList;
    }

    public Set<Employee> getEmpSets() {
        return empSets;
    }

    public void setEmpSets(Set<Employee> empSets) {
        this.empSets = empSets;
    }

    public Map<String, Employee> getEmpMap() {
        return empMap;
    }

    public void setEmpMap(Map<String, Employee> empMap) {
        this.empMap = empMap;
    }

    public Properties getPp() {
        return pp;
    }

    public void setPp(Properties pp) {
        this.pp = pp;
    }

    public Department() {
    }

    public Department(String name, String[] empName, List<Employee> empList, Set<Employee> empSets, Map<String, Employee> empMap, Properties pp) {
        this.name = name;
        this.empName = empName;
        this.empList = empList;
        this.empSets = empSets;
        this.empMap = empMap;
        this.pp = pp;
    }
}

Employee

package com.chenny.entity;

public class Employee {
    private String name;
    private int id;

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

    public String getName() {
        return name;
    }

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

    public int getId() {
        return id;
    }

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

    public Employee() {
    }

    public Employee(String name, int id) {
        this.name = name;
        this.id = id;
    }
}

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