DI（Dependency Injection），依赖注入是一种技术，即一个对象提供另一个对象的依赖关系。

 

构造注入

前提：类型必须有构造，index与参数类型保持一致

1.创建Student类

package cn.happy.day03aop.aop;/** * Created by Administrator on 2018/3/5. *///构造注入public class Student {    private String name;    private Integer age;    public Student() {    }    public Student(String name, Integer age) {        this.name = name;        this.age = age;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public Integer getAge() {        return age;    }    public void setAge(Integer age) {        this.age = age;    }}

2.配置applicationContext.xml文件

3.编写测试类

@Test    public void SpringStructure(){        ApplicationContext ctx=new ClassPathXmlApplicationContext("applicationContext-day04di.xml");        Student service=(Student)ctx.getBean("dao");        System.out.println( service.getName()+"\n"+service.getAge());    }

4.查看测试结果

 

p命名空间的注入

使用前要先要在applicationContext.xml配置文件中引入p命名空间

xmlns:p="http://www.springframework.org/schema/p"

1.1创建一个Car类

public class Car {    private String color;    public String getColor() {        return color;    }    public void setColor(String color) {        this.color = color;    }}

1.2在Student类中加入一个Car类型的car属性，并封装

2.配置applicationContext.xml

3.查看测试结果

 

集合属性注入

1.创建Mycollection类

package cn.happy.day03aop.aop;import java.util.*;/** * Created by Administrator on 2018/3/5. *///集合属性注入public class Mycollection {    private String[] array;    private List
     
       list;    private Set
      
        set;    private Map
       
         map;    private Properties properties;    @Override    public String toString() {        return "Mycollection{" +                "array=" + Arrays.toString(array) +                ", list=" + list +                ", set=" + set +                ", map=" + map +                ", properties=" + properties +                '}';    }    public String[] getArray() {        return array;    }    public void setArray(String[] array) {        this.array = array;    }    public List
        
          getList() {        return list;    }    public void setList(List
         
           list) {        this.list = list;    }    public Set
          
            getSet() { return set; } public void setSet(Set
           
             set) { this.set = set; } public Map
            
              getMap() { return map; } public void setMap(Map
             
               map) { this.map = map; } public Properties getProperties() { return properties; } public void setProperties(Properties properties) { this.properties = properties; }}
             
            
           
          
         
        
       
      
     

2.配置applicationContext.xml

         
             
              
                  
                       
        
         小李
                        
        
         小王
                    
               
              
              
                  
                       
        
         小张
                        
        
         小黄
                    
               
              
              
                  
                       
        
         小赵
                        
        
         小辉
                    
               
              
              
                  
               
              
              
                  
                       
        
         1
                        
        
         2
                    
               
          
     

3.测试

 

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