依赖注入的三种方式
1. 构造器注入
class UserService {
   private UserDao userDao;

   public UserService(UserDao userDao){
       this.userDao = userDao;
   }
}

2. setter注入
class Uservice {
   private UserDao userDao;

   public void setUserDao(UserDao userDao){
       this.userDao = userDao;
}

3. 感知接口注入
interface UserDaoAware {
   public void injectUserDao(UserDao userDao);
}

class UserService implements UserDaoAware {

   private UserDao userDao;

   public void injectUserDao(UserDao userDao){
       this.userDao = userDao;
   }
}

Spring支持前两种方式

Employee

package main.com.lee.e_di;
/**
 * 雇员
 *
 * @author Lynch
 *
 */
public class Employee {
    private Integer age;
    private String name;
    private Product product;
    public void setProduct(Product product) {
        this.product = product;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public void setName(String name) {
        this.name = name;
    }
    @Override
    public String toString() {
        return "Employee [age=" + age + ", name=" + name + ", product=" + product + "]";
    }
}


EmployeeInfo

package main.com.lee.e_di;
/**
 * 数据bean
 *
 * @author Lynch
 *
 */
public class EmployeeInfo {
    private String name = "周通";
    private Integer age = 23;
    public String getName() {
        return name;
    }
    public Integer peekAge() {
        return age;
    }
}

Product

package main.com.lee.e_di;
/**
 * 商品
 */
public class Product {
    private String name;
    private Double price;
    public Product(String name, Double price) {
        this.name = name;
        this.price = price;
    }
    @Override
    public String toString() {
        return "Product [name=" + name + ", price=" + price + "]";
    }
}

Student

package main.com.lee.e_di;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
public class Student {
    private String[] aArr;
    private List aList;
    private Set aSet;
    private Map aMap;
    private Properties properties;
    public void setProperties(Properties properties) {
        this.properties = properties;
    }
    public void setaArr(String[] aArr) {
        this.aArr = aArr;
    }
    public void setaList(List aList) {
        this.aList = aList;
    }
    public void setaSet(Set aSet) {
        this.aSet = aSet;
    }
    public void setaMap(Map aMap) {
        this.aMap = aMap;
    }
    @Override
    public String toString() {
        return "Student [aArr=" + Arrays.toString(aArr) + ", aList=" + aList + ", aSet=" + aSet + ", aMap=" + aMap + ", properties=" + properties
                + "]";
    }
}

applicationCotext.xml



    
    



    
    
    



                                    



    
    
    



    
        
            数组值1
            数组值2
        
    
    
        
            列表值1
            列表值2
        
    
    
        
            集合值1
            集合值2
            集合值2
        
    
    
        
            
            
                
                    key2
                
                映射值2
            
        
    
    
        
            值1
            值2

Test

package main.com.lee.e_di;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
/**
 * 依赖注入方式小测
 *
 * @author Lynch
 *
 */
public class BeanDITest {
    @Test
    public void demo1() {
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        // 构造器注入
        Product product = (Product) applicationContext.getBean("product");
        System.out.println(product);
        // setter注入
        Employee employee = (Employee) applicationContext.getBean("employee");
        System.out.println(employee);
        // p名称空间注入
        Employee employee2 = (Employee) applicationContext.getBean("employee2");
        System.out.println(employee2);
        // SpEL注入
        Employee employee3 = (Employee) applicationContext.getBean("employee3");
        System.out.println(employee3);
        // 集合注入
        Student student = (Student) applicationContext.getBean("student");
        System.out.println(student);
    }
}

out

Product [name=宝马, price=1111.1]
Employee [age=23, name=成龙, product=Product [name=宝马, price=1111.1]]
Employee [age=44, name=李连杰, product=Product [name=宝马, price=1111.1]]
Employee [age=23, name=周通, product=Product [name=宝马, price=1111.1]]
Student [aArr=[数组值1, 数组值2], aList=[列表值1, 列表值2], aSet=[集合值1, 集合值2], aMap={key1=映射值1, key2=映射值2}, properties={key2=值2, key1=值1}]