Mode 2-Immutable

Come to Java multi-thread design mode

I. Method: the synchronized method is not required and remains unchanged. No method can be modified by the outside world. Only the read method is provided.

 Public   Final   Class Person { Private FinalString name;Private FinalString address;      Public Person (string name, string address ){ This . Name = Name; This . Address = address ;} Public String getname (){ Return Name ;} Public String getaddress (){ Return Address ;} Public String tostring (){ Return " [Person: Name = "+ Name +" , Address = "+ Address +" ] ";}}

 
Ii. uneasily discovered errors:
 

 Public   Final   Class Userinfo { Private   Final Stringbuffer Info; Public Userinfo (string name, string address ){ This . Info = New Stringbuffer (" <Info name = \" "+ Name +" \ "Address = \" "+ Address +" \ "/> ");}  PublicStringbuffer getinfo (){ReturnInfo ;}      Public String tostring (){ Return " [Userinfo: "+ Info +" ] ";}}

 Public   Class Main { Public   Static   Void Main (string [] ARGs ){ // Create an object Userinfo = New Userinfo (" Alice "," Alaska "); // Display System. Out. println (" Userinfo = "+ Userinfo );// Status change          Stringbuffer info = userinfo. getinfo (); Info. Replace (12, 17 ,"Bobby");   // "Alice" found 12... 16          // Display again System. Out. println (" Userinfo = "+ Userinfo );}}

 
Result:
 

 
Userinfo = [userinfo: <info name ="Alice"Address ="Alaska"/>] Userinfo = [userinfo: <info name ="Bobby"Address ="Alaska"/>]
 

 

 Public   Final   Class Immutableperson { Private   Final String name; Private   Final String address; Public Immutableperson (string name, string address ){ This . Name = Name; This . Address = address ;} PublicImmutableperson (mutableperson person ){This. Name = person. getname ();This. Address = person. getaddress ();}      Public Mutableperson getmutableperson (){ Return   New Mutableperson ( This );} Public String getname (){ Return Name ;} Public String getaddress (){ Return Address ;} Public String tostring (){ Return " [Immutableperson: "+ Name +" , "+ Address +"] ";}}

 
 Public Synchronized VoidSetperson (string newname, string newaddress){Name = newname; address = newaddress ;}
 

 
When immutableperson (mutableperson person) is executed, the name and address of the person may not match.