Spring – 带有集合的 Setter 注入

依赖注入是Spring IOC（Inversion of Control）提供的主要功能。 Spring-Core 模块负责通过 Constructor 或 Setter 方法注入依赖项。在 Setter 依赖注入（SDI）中，依赖将在 setter 和 getter 方法的帮助下注入。 bean 配置文件用于将 DI 设置为 bean 中的 SDI。为此，要使用 SDI 设置的属性在 bean-config 文件中的 标记下声明。

Java中的 Collection 是一组单独的对象。 Spring 框架使用以下集合为我们提供了 Setter 注入工具：

• 列表
• 地图
• 放

执行：

一家公司。Java

A company has a list of employees.

Java

// Java program to Illustrate Company Class
 
package com.geeksforgeeks.org;
 
// Importing required classes
import java.util.*;
 
// Company Class
class Company {
 
    // Class data members
    private String companyName;
    private List employees;
 
    // Setter
    public void setCompanyName(String companyName)
    {
        this.companyName = companyName;
    }
 
    // Setter
    public void setEmployees(List employees)
    {
        this.employees = employees;
    }
 
    // Getter
    public String getCompanyName() { return companyName; }
 
    // Getter
    public List getEmployees() { return employees; }
 
    // Method
    public void display()
    {
        System.out.println("Company: " + companyName);
        System.out.println("Employee list: " + companyName);
 
        // Iterating over using for each loop
        for (String employee : employees) {
            System.out.println("-" + employee);
        }
    }
}

B.applicationContext.xml

我们将使用属性元素进行 setter 注入。 property 属性的name元素将等于变量名称，而value元素将包含您要分配给该变量的值。

XML

 
 
   
     
         
        
            
                 "John"
                "Max"
                "Sam"
             
         
     
 

C. 主要的。Java

Java

// Java Program to Illustrate Application Class
 
package com.geeksforgeeks.org;
 
// Importing required classes
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;
 
// Application (Main) Class
public class Main {
 
    // Main driver method
    public static void main(String[] args)
    {
        // Creating a new class path resource
        Resource resource = new ClassPathResource(
            "applicationContext.xml");
 
        // Creating an object of BeanFactory class
        BeanFactory factory = new XmlBeanFactory(resource);
 
        // Creating an object of Employee class
        Employee e = (Employee)factory.getBean("employee");
 
        // Calling display() method inside main() method
        e.display();
    }
}

输出：

Company: GeeksForGeeks
Employee list:
-John
-Max
-Sam