Advanced spring Functions

Automatic Assembly

Spring can automatically assemble the dependencies between Bean and Bean without using ref to display specified dependent beans.
Pass The default-autowire attribute of the element can also be specified through the autowire attribute.
No: automatic assembly is not used and must be defined by ref.
ByName: Automatic Assembly Based on Attribute names
ByType: Automatic Assembly Based on the property type
Constructor: automatically assembled Based on the attribute name, using constructor
Autodetect: byType or constructor is determined by beanFactory. There is a default constructor, and byType is used;

Spring will be automatically searched and assembled at startup. If you do not want automatic assembly, you can use
Autowire-candidate = "false"

Example 1:

Reply. java

Package auto; public class Reply {private String id; private String title; private String content; private Topic topic; // constructor public Reply () {System. out. println ("reply created");} public String getId () {return id;} public void setId (String id) {this. id = id;} public String getTitle () {return title;} public void setTitle (String title) {this. title = title;} public String getContent () {return content;} public void setContent (String content) {this. content = content;} public Topic getTopic () {return topic;} public void setTopic (Topic topic) {this. topic = topic ;}}

Topic. java

Package auto; import java. util. List; public class Topic {private String id; private String title; private String Content; // The set inherits the private List
 
  
Names; public List
  
   
GetNames () {return names;} public void setNames (List
   
    
Names) {this. names = names;} public String getId () {return id;} public void setId (String id) {this. id = id;} public String getContent () {return Content;} public void setContent (String content) {Content = content;} public String getTitle () {return title ;} public void setTitle (String title) {this. title = title ;}}
   
  
 

ApplicationContext. xml

 
 
  
   
    
     
1
    
   
   
    
     
Xxxx
    
   
   
    
     
Yy
    
   
  
   
   
   
    
   
    
     
1
    
   
   
    
     
Zhenhao
    
   
   
    
     
Xuexi
    
   
   
   
 

Test code

/** Query by XML file */ApplicationContext context = new ClassPathXmlApplicationContext ("applicationContext. xml "); Reply reply = context. getBean ("reply", Reply. class); System. out. println (reply. getTopic (). getTitle ());

Running result:

Reply created
Xxxx

Construct a annotation configuration class through configuration class Query

Config. java

Package cofig; import org. springframework. beans. factory. annotation. value; import org. springframework. context. annotation. bean; import org. springframework. context. annotation. configuration; import auto. topic; // annotation injection, change config to Configuration class @ Configuration public class Config {// assign a Value to the attribute @ value (Value = "csdn") public String name; // obtain the object named topic3 @ Bean (name = "topic3") public Topic getTopic () {Topic topic = new Topic (); topic. setTitle ("java"); topic. setContent ("ccxcc"); return topic ;}}

Test code

/** Construct a annotation configuration class through configuration class query and perform manual intervention */ApplicationContext context = new AnnotationConfigApplicationContext (Config. class); Topic topic = context. getBean ("topic3", Topic. class); System. out. println (topic. getTitle () + "--" + topic. getContent ());

Running result:

Java -- ccxcc

Inherit parent class labels

Configure in XML file

 
    
  
      
         
    
     
789
       
   
  
 

Test code

/*** Inherit from the Collection class and output all attributes in the Set */ApplicationContext context = new ClassPathXmlApplicationContext ("applicationContext. xml "); Topic topic = context. getBean ("topic1", Topic. class); System. out. println (topic. getNames ());

Running result:

Reply created
[123,245,789]

Different types of Inheritance

Talk. java

Package auto; import java. util. List; public class Talk {private String id; private String title; private String Content; private List
 
  
Names; public String getId () {return id;} // implements the constructor public Talk () {System. out. println ("talk created");} public void setId (String id) {this. id = id;} public String getTitle () {return title;} public void setTitle (String title) {this. title = title;} public String getContent () {return Content;} public void setContent (String content) {Content = content;} public List
  
   
GetNames () {return names;} public void setNames (List
   
    
Names) {this. names = names ;}}
   
  
 

Configure in XML file

Test code

/*** Different types of inheritance */ApplicationContext context = new ClassPathXmlApplicationContext ("applicationContext. xml "); Talk topic = context. getBean ("talk", Talk. class); System. out. println (topic. getNames (); System. out. println (topic. getTitle ());

Running result:

Talk created
Reply created
[123,245]
Xxxx

Factory TopicFactory. java

Package factory; import org. springframework. beans. factory. FactoryBean; import auto. Topic; public class TopicFactory implements FactoryBean
 
  
{Private Topic topic; // returned object @ Overridepublic Topic getObject () throws Exception {// Singleton mode if (topic = null) {topic = new Topic ();} return topic;} // return object type @ Overridepublic Class
  GetObjectType () {return Topic. class;} // determines whether the object is a singleton () {return true ;}}
 

Bean. xml

Test code:

// Factory ApplicationContext context = new ClassPathXmlApplicationContext ("bean. xml "); Topic topic = context. getBean ("topic", Topic. class); topic. setId ("110"); System. out. println (topic. getId (); Topic topic1 = context. getBean ("topic", Topic. class); System. out. println (topic1.getId ());

Running result:

110
110