Hibernate generates a custom primary key (similar to user000000001-you can configure it by yourself through the configuration file)

Primary Key Generation class

View code

 1   Package  Action;  2   3   Import  Java. Io. serializable;  4   Import  Java. util. List;  5   Import  Java. util. properties;  6   7  Import  Org. hibernate. hibernateexception;  8   Import  Org. hibernate. mappingexception;  9   Import  Org. hibernate. dialect. dialect;  10   Import  Org. hibernate. Engine. queryparameters;  11   Import  Org. hibernate. Engine. sessionimplementor;  12  Import  Org. hibernate. Id. retriable;  13   Import  Org. hibernate. Id. identifiergenerator;  14   Import  Org. hibernate. type. type;  15   /**  16   *  17   * Class Name: generatepk  18  * Class description: automatically generates a custom primary key based on hibernate.  19   * Created by: andy_lj  20   * Creation Time: 11:40:50 AM  21   * Modify remarks:  22   *  @ Version  23    */  24   Public   Class Generatepk Implements Retriable, identifiergenerator {  25       Public String sign; //  User in user000000001  26       Public String classname; //  Object Class Name  27       Public String PK; //  Primary Key name  28       Public String idlength;//  Length of user000000001  29       30       /**  31   * Get the custom value in user. HBM. xml.  32        */  33   @ Override  34       Public   Void  Configure (type arg0, properties arg1, dialect arg2)  35              Throws  Mappingexception {  36           This . Classname = arg1.getproperty ("classname" );  37           This . PK = arg1.getproperty ("Pk" );  38           This . Sign = arg1.getproperty ("sign" );  39           This . Idlength = arg1.getproperty ("idlength" ); 40   }  41       /**  42   * Generate a primary key  43        */  44   @ Override  45       Public  Serializable generate (sessionimplementor arg0, object arg1)  46               Throws  Hibernateexception { 47            //  Obtain the length of the primary key  48           Int Leng = Integer. valueof (idlength );  49           //  The maximum ID number in the database to be queried  50 Stringbuffer SQL = New Stringbuffer ("select max (." ). Append (PK)  51 . Append (") from" ) 52   . Append (classname)  53 . Append ("as a where ." )  54   . Append (PK)  55 . Append ("like '" )  56   . Append (sign)  57 . Append ("% '" );  58 Queryparameters QP = New  Queryparameters ();  59 List ls = Arg0.list (SQL. tostring (), qP );  60 String max = (string) ls. Get (0 );  61           Int I = 0 ;  62           // If it is the first time to add a record, it is similar to user000000001.  63           If (Max = Null | Max. Trim (). Equals ("" )){  64 Max = "1" ;  65               For (; I <leng-sign.length ()-1; I ++ ){  66 Max = "0" + Max;  67   } 68 I = 0 ;  69               Return Sign + Max;  70 } //  This is not the first operation, and the record length does not exceed the length read from the configuration file  71           Else   If (Max! = Null & MAX. Length () <= Leng ){  72 Max = max. replaceall (sign ,"");  73 Integer IMAX = integer. parseint (max) + 1 ;  74 String returnnum = String. valueof (IMAX );  75               Int Zero = leng-sign.length ()- Returnnum. Length ();  76               For (; I <zero; I ++ ){  77 Returnnum = "0" + Returnnum; 78   }  79 I = 0 ;  80               Return Sign + Returnnum;  81 } //  This is not the first operation. The record length exceeds the length read from the configuration file.  82           Else  {  83 Leng = Max. Length (); 84 Max = max. replaceall (sign ,"" );  85 Integer IMAX = integer. parseint (max) + 1 ;  86 String returnnum = String. valueof (IMAX );  87               Int Zero = leng-sign.length ()- Returnnum. Length ();  88               For (; I <zero; I ++ ){  89 Returnnum = "0" + Returnnum;  90   }  91               Return Sign + Returnnum;  92   }  93   }  94   95 }

 

Configuration File: User. HBM. xml

View code

 1  <?  XML version = "1.0" encoding = "UTF-8"  ?>  2   <!  Doctype hibernate-mapping public  3   "-// Hibernate/hibernate mapping DTD 3.0 // en"  4   Http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"  >  5   <  Hibernate-Mapping  Package = "Entity"  >  6       <  Class  Name  = "User"  Table  = "Temp"  Lazy  = "False"  >  7           <  ID  Name  = "Userid" Column  = "Userid"  >  8               <  Generator  Class  = "Action. generatepk"   >  9                 <  Param  Name  = "Classname"  > User </  Param >  10                 <  Param  Name  = "Pk"  > Userid </  Param  >  11                 <  Param  Name  = "Sign"  > Poli </ Param  >  12                 <  Param  Name  = "Idlength"  > 13 </  Param  >  13               </  Generator  >  14           </ ID  >  15           <  Property  Name  = "Name"  Column  = "Name"   />  16           <  Property  Name  = "Age"  Column  = "Age" Type  = "Integer"  />  17           <  Property  Name  = "Address"  Column  = "Address"   />  18       </  Class  >  19   </ Hibernate-Mapping  >