Convert Enum to smallint using hibernate

For database reasons, smallint must be used to store enumeration types.

Hibernate 3.0 or above also supports Enum type conversion. Here we take smallint as an example (of course, we can also convert it to another type, such as varchar ).

 

First, the following is an enumeration type

1. Public Enum consumertype
2. {
3. Admin, vistor, VIP;
5. }

Then, write another template to implement the usertype interface. In this way, you can convert all the enumeration types written later to smallint and save them to the database.

 

1. Import java. Io. serializable;
2. Import java. SQL. preparedstatement;
3. Import java. SQL. resultset;
4. Import java. SQL. sqlexception;
5. Import java. SQL. types;
7. Import org. hibernate. hibernateexception;
8. Import org. hibernate. usertype. usertype;
11. Public class intenumusertype <E extends Enum <E> implements usertype
12. {
13. Private class <E> clazz = NULL;
14. Private e [] theenumvalues;
17. Protected intenumusertype (class <E> C, E [] E)
18. {
19. This. clazz = C;
20. This. theenumvalues = E;
21. }
23. Private Static final int [] SQL _types = {types. smallint };
26. Public int [] sqltypes ()
27. {
28. Return SQL _types;
29. }
31. Public class <E> returnedclass ()
32. {
33. Return clazz;
34. }
37. Public object nullsafeget (resultset, string [] names, object owner)
38. Throws hibernateexception, sqlexception
39. {
40. Final int val = resultset. getshort (Names [0]);
41. E result = NULL;
42. If (! Resultset. wasnull ())
43. {
44. Try
45. {
46. For (INT I = 0; I <theenumvalues. Length & Result = NULL; I ++)
47. {
48. If (theenumvalues [I]. ordinal () = Val)
49. {
50. Result = theenumvalues [I];
51. }
52. }
53. }
54. Catch (securityexception E)
55. {
56. Result = NULL;
57. }
58. Catch (illegalargumentexception E)
59. {
60. Result = NULL;
61. }
62. }
63. Return result;
64. }
67. Public void nullsafeset (preparedstatement,
68. Object value, int index) throws hibernateexception, sqlexception
69. {
70. If (null = value)
71. {
72. Preparedstatement. setnull (index, types. smallint );
73. }
74. Else
75. {
76. Preparedstatement. setint (index, (Enum) value). ordinal ());
77. }
78. }
80. Public object deepcopy (object Value) throws hibernateexception
81. {
82. Return value;
83. }
85. Public Boolean ismutable ()
86. {
87. Return false;
88. }
90. Public object assemble (serializable cached, object owner) throws hibernateexception
91. {
92. Return cached;
93. }
95. Public serializable disassemble (object Value) throws hibernateexception
96. {
97. Return (serializable) value;
98. }
100. Public object Replace (Object original, object target, object owner) throws hibernateexception
101. {
102. Return Original;
103. }
104. Public int hashcode (Object X) throws hibernateexception
105. {
106. Return X. hashcode ();
107. }
108. Public Boolean equals (Object X, object y) throws hibernateexception
109. {
110. If (x = y)
111. Return true;
112. If (null = x | null = y)
113. Return false;
114. Return X. Equals (y );
115. }
116. }

Next, create a class to implement the template.

 

1. /** This class is used only in the hibernate xml configuration */
2. Public class consumertypeenum extends intenumusertype <consumertype>
3. {
4. Public consumertypeenum ()
5. {
6. // We must give the values of the enum to the parent.
7. Super (consumertype. Class, consumertype. Values ());
8. }
9. }

Finally, use the following code in the mapping XML file:

 

1. <Property column = "usertpye"
2. Not-null = "true"
3. Name = "consumertype"
4. Type = "consumertypeenum"/>

Note that consumertypeenum is used instead of consumertype.

 

At this point, the conversion is complete ~