Spring对象注入和复杂(Array、List、Map、Properties)属性注入

忘是亡心i 2022-01-28 01:23 665阅读 0赞

### 对象注入 ###

创建两个对象：

public class UserService { 
        private UserDao userDao;
        //set一定要小写
        public void setUserDao(UserDao dao) { 
            userDao = dao;
        }
         public void add() { 
             System.out.println("Service........");
            userDao.add();
         }
    }

package ioc;
    
    public class UserDao { 
        public void add() { 
            System.out.println("Dao........");
        }
    }

然后使用set方法进行属性注入**注意：set方法一定要小写，否则会报错**  
配置xml文件，注意不是value，而是ref表示bean对象的引用，有两个对象，因此创建两个bean

然后运行：

public class TestService { 
        @Test
        public void test() { 
            ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");
            UserService service = (UserService) context.getBean("service");
            service.add();
        }
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zNjM3Mjg3OQ_size_16_color_FFFFFF_t_70]  
可以看到对象注入成功。

--------------------

### 复杂属性注入 ###

Person类里面有一些复杂属性：

package property;
    import java.util.*;
    
    public class Person { 
        //使用p名称空间来进行属性注入
        private String name;
    
        public void setName(String name) { 
            this.name = name;
        }
        public void test() { 
            System.out.println(name);
        }
    
        private String[] arrs;
        private List<String> list;
        private Map<String, String> map;
        private Properties properties;
    
        public void setArrs(String[] arrs) { 
            this.arrs = arrs;
        }
    
        public void setList(List<String> list) { 
            this.list = list;
        }
    
        public void setMap(Map<String, String> map) { 
            this.map = map;
        }
    
        public void setProperties(Properties properties) { 
            this.properties = properties;
        }
    
        public void test1() { 
            System.out.println("array" + arrs);
            System.out.println("list" + list);
            System.out.println("map" + map);
            System.out.println("pro" + properties);
        }
    }

注入方法：

<bean id="person" class="property.Person">
            
             <property name="arrs">
                 <list>
                     <value>"hello"</value>
                     <value>"world"</value>
                     <value>"array"</value>
                 </list>
             </property>
            
            <property name="list">
                <list>
                    <value>"pig"</value>
                    <value>"cat"</value>
                </list>
            </property>
            
            <property name="map">
                <map>
                    <entry key="aa" value="Lucy"></entry>
                    <entry key="bb" value="Mary"></entry>
                    <entry key="cc" value="Tom"></entry>
                </map>
            </property>
            
            <property name="properties">
                <props>
                    <prop key="driverClass">com.mysql.jdbc.Driver</prop>
                    <prop key="userName">root</prop>
                </props>
            </property>
        </bean>

Properties是键值对的意思  
注意之后不能回车，否则将把回车和换行都加入到List里面。  
测试：

public void testPerson() { 
             ApplicationContext context = new ClassPathXmlApplicationContext("bean1.xml");
             Person person = (Person) context.getBean("person");
             person.test1();
        }

测试结果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zNjM3Mjg3OQ_size_16_color_FFFFFF_t_70 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zNjM3Mjg3OQ_size_16_color_FFFFFF_t_70]: /images/20220128/21b25211118e44bbaf993eeaf89d3e46.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl8zNjM3Mjg3OQ_size_16_color_FFFFFF_t_70 1]: /images/20220128/0ba0bb68605d461f9ff5934ae5c79648.png