5.注入参数详解

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
 4     xmlns:context="http://www.springframework.org/schema/context"
 5     xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
 6     xsi:schemaLocation="http://www.springframework.org/schema/beans
 7        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
 8        http://www.springframework.org/schema/context
 9        http://www.springframework.org/schema/context/spring-context-3.1.xsd
10        http://www.springframework.org/schema/tx
11        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
12        http://www.springframework.org/schema/aop
13        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
14        
15      
16     <bean id="car" class="com.asm.Car" >
17         <property name="maxSpeed">
18             <value>200</value>
19         </property>
20         <property name="brand">
21             <value><![CDATA[奥迪&CA72]]></value>
22         </property>
23     </bean>
24     
25  </beans>

当有特殊字符的时候<![CDATA[]]>

2.引用其他bean

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
 4     xmlns:context="http://www.springframework.org/schema/context"
 5     xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
 6     xsi:schemaLocation="http://www.springframework.org/schema/beans 
 7        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
 8        http://www.springframework.org/schema/context 
 9        http://www.springframework.org/schema/context/spring-context-3.1.xsd
10        http://www.springframework.org/schema/tx 
11        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
12        http://www.springframework.org/schema/aop
13        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
14        
15      
16     
17     <bean id="car" class="com.asm.Car" />
18     <bean id="boss" class="com.asm.Boss">
19         <property name="car">
20             <ref bean="car"/>
21         </property>
22     </bean>
23  </beans>

3.集合类属性

List;

 1 package com.asm;
 2 
 3 
 4 import java.util.ArrayList;
 5 import java.util.List;
 6 
 7 import org.springframework.beans.BeansException;
 8 import org.springframework.beans.factory.BeanFactory;
 9 import org.springframework.beans.factory.BeanFactoryAware;
10 import org.springframework.beans.factory.BeanNameAware;
11 import org.springframework.beans.factory.DisposableBean;
12 import org.springframework.beans.factory.InitializingBean;
13 
14 public class Car {
15     private String brand;
16     private String color;
17     private int maxSpeed;
18     
19     private List abc = new ArrayList();    
20     
21     public List getAbc() {
22         return abc;
23     }
24     public void setAbc(List abc) {
25         this.abc = abc;
26     }
27     public String getBrand() {
28         return brand;
29     }
30     public void setBrand(String brand) {
31         this.brand = brand;
32     }
33     public String getColor() {
34         return color;
35     }
36     public void setColor(String color) {
37         this.color = color;
38     }
39     public int getMaxSpeed() {
40         return maxSpeed;
41     }
42     public void setMaxSpeed(int maxSpeed) {
43         this.maxSpeed = maxSpeed;
44     }
45 
46 
47 }

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
 4     xmlns:context="http://www.springframework.org/schema/context"
 5     xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
 6     xsi:schemaLocation="http://www.springframework.org/schema/beans 
 7        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
 8        http://www.springframework.org/schema/context 
 9        http://www.springframework.org/schema/context/spring-context-3.1.xsd
10        http://www.springframework.org/schema/tx 
11        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
12        http://www.springframework.org/schema/aop
13        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
14        
15      
16     <bean id="car" class="com.asm.Car" >
17         <property name="maxSpeed">
18             <value>200</value>
19         </property>
20         <property name="brand">
21             <value><![CDATA[奥迪&CA72]]></value>
22         </property>
23         <property name="abc">
24             <list>
25                 <value>看报</value>
26                 <value>赛车</value>
27                 <value>高尔夫</value>
28             </list>
29         </property>
30     </bean>
31 
32  </beans>

Map:

 1 package com.asm;
 2 
 3 
 4 import java.util.ArrayList;
 5 import java.util.HashMap;
 6 import java.util.List;
 7 import java.util.Map;
 8 
 9 import org.springframework.beans.BeansException;
10 import org.springframework.beans.factory.BeanFactory;
11 import org.springframework.beans.factory.BeanFactoryAware;
12 import org.springframework.beans.factory.BeanNameAware;
13 import org.springframework.beans.factory.DisposableBean;
14 import org.springframework.beans.factory.InitializingBean;
15 
16 public class Car {
17     private String brand;
18     private String color;
19     private int maxSpeed;
20     
21     private List abc = new ArrayList();    
22     private Map map = new HashMap();
23     
24     
25     
26     public Map getMap() {
27         return map;
28     }
29     public void setMap(Map map) {
30         this.map = map;
31     }
32     public List getAbc() {
33         return abc;
34     }
35     public void setAbc(List abc) {
36         this.abc = abc;
37     }
38     public String getBrand() {
39         return brand;
40     }
41     public void setBrand(String brand) {
42         this.brand = brand;
43     }
44     public String getColor() {
45         return color;
46     }
47     public void setColor(String color) {
48         this.color = color;
49     }
50     public int getMaxSpeed() {
51         return maxSpeed;
52     }
53     public void setMaxSpeed(int maxSpeed) {
54         this.maxSpeed = maxSpeed;
55     }
56 
57 
58 }

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
 4     xmlns:context="http://www.springframework.org/schema/context"
 5     xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
 6     xsi:schemaLocation="http://www.springframework.org/schema/beans 
 7        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
 8        http://www.springframework.org/schema/context 
 9        http://www.springframework.org/schema/context/spring-context-3.1.xsd
10        http://www.springframework.org/schema/tx 
11        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
12        http://www.springframework.org/schema/aop
13        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
14        
15      
16     <bean id="car" class="com.asm.Car" >
17         <property name="maxSpeed">
18             <value>200</value>
19         </property>
20         <property name="brand">
21             <value><![CDATA[奥迪&CA72]]></value>
22         </property>
23         <property name="abc">
24             <list>
25                 <value>看报</value>
26                 <value>赛车</value>
27                 <value>高尔夫</value>
28             </list>
29         </property>
30         <property name="map">
31             <map>
32                 <entry>
33                     <key><value>AM</value></key>
34                     <value>abcabc</value>
35                 </entry>
36                 <entry>
37                     <key><value>AM111</value></key>
38                     <value>abcabc1111</value>
39                 </entry>
40             </map>
41         </property>
42     </bean>
43 
44  </beans>

property

 1 package com.asm;
 2 
 3 
 4 import java.util.ArrayList;
 5 import java.util.HashMap;
 6 import java.util.List;
 7 import java.util.Map;
 8 import java.util.Properties;
 9 
10 import org.springframework.beans.BeansException;
11 import org.springframework.beans.factory.BeanFactory;
12 import org.springframework.beans.factory.BeanFactoryAware;
13 import org.springframework.beans.factory.BeanNameAware;
14 import org.springframework.beans.factory.DisposableBean;
15 import org.springframework.beans.factory.InitializingBean;
16 
17 public class Car {
18     private String brand;
19     private String color;
20     private int maxSpeed;
21     
22     private List abc = new ArrayList();    
23     private Map map = new HashMap();
24     private Properties mail = new Properties();
25     
26     public Properties getMail() {
27         return mail;
28     }
29     public void setMail(Properties mail) {
30         this.mail = mail;
31     }
32     public Map getMap() {
33         return map;
34     }
35     public void setMap(Map map) {
36         this.map = map;
37     }
38     public List getAbc() {
39         return abc;
40     }
41     public void setAbc(List abc) {
42         this.abc = abc;
43     }
44     public String getBrand() {
45         return brand;
46     }
47     public void setBrand(String brand) {
48         this.brand = brand;
49     }
50     public String getColor() {
51         return color;
52     }
53     public void setColor(String color) {
54         this.color = color;
55     }
56     public int getMaxSpeed() {
57         return maxSpeed;
58     }
59     public void setMaxSpeed(int maxSpeed) {
60         this.maxSpeed = maxSpeed;
61     }
62 
63 
64 }

 1 <?xml version="1.0" encoding="UTF-8" ?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
 4     xmlns:context="http://www.springframework.org/schema/context"
 5     xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
 6     xsi:schemaLocation="http://www.springframework.org/schema/beans 
 7        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
 8        http://www.springframework.org/schema/context 
 9        http://www.springframework.org/schema/context/spring-context-3.1.xsd
10        http://www.springframework.org/schema/tx 
11        http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
12        http://www.springframework.org/schema/aop
13        http://www.springframework.org/schema/aop/spring-aop-3.1.xsd">
14        
15      
16     <bean id="car" class="com.asm.Car" >
17         <property name="maxSpeed">
18             <value>200</value>
19         </property>
20         <property name="brand">
21             <value><![CDATA[奥迪&CA72]]></value>
22         </property>
23         <property name="abc">
24             <list>
25                 <value>看报</value>
26                 <value>赛车</value>
27                 <value>高尔夫</value>
28             </list>
29         </property>
30         <property name="map">
31             <map>
32                 <entry>
33                     <key><value>AM</value></key>
34                     <value>abcabc</value>
35                 </entry>
36                 <entry>
37                     <key><value>AM111</value></key>
38                     <value>abcabc1111</value>
39                 </entry>
40             </map>
41         </property>
42         <property name="mail">
43             <props>
44                 <prop key="mail">
45                     abcbaacacac
46                 </prop>
47             </props>
48         </property>
49     </bean>
50 
51  </beans>

Spring3系列8- Spring 自动装配 Bean

1. Auto-Wiring ‘no’

2. Auto-Wiring ‘byName’

3. Auto-Wiring ‘byType

4. Auto-Wiring ‘constructor’

5. Auto-Wiring ‘autodetect’

Spring Auto-Wiring Beans——Spring自动装配Bean

所谓自动装配，就是将一个Bean注入到其他Bean的Property中，类似于以下：

<bean id="customer" class="com.lei.common.Customer" autowire="byName" />

Spring支持5种自动装配模式，如下：

no 　　——默认情况下，不自动装配，通过“ref”attribute手动设定。

buName ——根据Property的Name自动装配，如果一个bean的name，和另一个bean中的Property的name相同，则自动装配这个bean到Property中。

byType 　　——根据Property的数据类型（Type）自动装配，如果一个bean的数据类型，兼容另一个bean中Property的数据类型，则自动装配。

constructor ——根据构造函数参数的数据类型，进行byType模式的自动装配。

autodetect ——如果发现默认的构造函数，用constructor模式，否则，用byType模式。

下例中演示自动装配

Customer.java如下：

package com.lei.common;
 
public class Customer 
{
    private Person person;
 
    public Customer(Person person) {
        this.person = person;
    }
 
    public void setPerson(Person person) {
        this.person = person;
    }
    //...
}

Person.java如下：

package com.lei.common;
 
public class Person 
{
    //...
}

1. Auto-Wiring ‘no’

默认情况下，需要通过'ref’来装配bean，如下：

<bean id="customer" class="com.lei.common.Customer">
    <property name="person" ref="person" />
</bean>
 <bean id="person" class="com.lei.common.Person" />

2. Auto-Wiring ‘byName’

根据属性Property的名字装配bean，这种情况，Customer设置了autowire="byName"，Spring会自动寻找与属性名字“person”相同的bean，找到后，通过调用setPerson(Person person)将其注入属性。

<bean id="customer" class="com.lei.common.Customer" autowire="byName" />

<bean id="person" class="com.lei.common.Person" />

如果根据 Property name找不到对应的bean配置，如下

<bean id="customer" class="com.lei.common.Customer" autowire="byName" />

<bean id="person_another" class="com.lei.common.Person" />

Customer中Property名字是person，但是配置文件中找不到person，只有person_another，这时就会装配失败，运行后，Customer中person=null。

3. Auto-Wiring ‘byType

根据属性Property的数据类型自动装配，这种情况，Customer设置了autowire="byType"，Spring会总动寻找与属性类型相同的bean，找到后，通过调用setPerson(Person person)将其注入。

<bean id="customer" class="com.lei.common.Customer" autowire="byType" />

<bean id="person" class="com.lei.common.Person" />

如果配置文件中有两个类型相同的bean会怎样呢？如下：

<bean id="customer" class="com.lei.common.Customer" autowire="byType" />

<bean id="person" class="com.lei.common.Person" />

<bean id="person_another" class="com.lei.common.Person" />

一旦配置如上，有两种相同数据类型的bean被配置，将抛出UnsatisfiedDependencyException异常，见以下：

Exception in thread "main" org.springframework.beans.factory.UnsatisfiedDependencyException:

所以，一旦选择了’byType’类型的自动装配，请确认你的配置文件中每个数据类型定义一个唯一的bean。

4. Auto-Wiring ‘constructor’

这种情况下，Spring会寻找与参数数据类型相同的bean，通过构造函数public Customer(Person person)将其注入。

<bean id="customer" class="com.lei.common.Customer" autowire="constructor" />

<bean id="person" class="com.lei.common.Person" />

5. Auto-Wiring ‘autodetect’

这种情况下，Spring会先寻找Customer中是否有默认的构造函数，如果有相当于上边的’constructor’这种情况，用构造函数注入，否则，用’byType’这种方式注入，所以，此例中通过调用public Customer(Person person)将其注入。

<bean id="customer" class="com.lei.common.Customer" autowire="autodetect" />

<bean id="person" class="com.lei.common.Person" />

注意：

项目中autowire结合dependency-check一起使用是一种很好的方法，这样能够确保属性总是可以成功注入。

<bean id="customer" class="com.lei.common.Customer"

            autowire="autodetect" dependency-check="objects" />

<bean id="person" class="com.lei.common.Person" />

最后，我认为，自动装配虽然让开发变得更快速，但是同时却要花更大的力气维护，因为它增加了配置文件的复杂性，你甚至不知道哪一个bean会被自动注入到另一个bean中。我更愿意写配置文件来手工装配。

posted on 2016-06-18 00:16 Sharpest 阅读(320) 评论(0) 收藏举报