數據庫clob轉字符串，大字段 CLOB/BOLB與String互轉

String s1="1234abc我是大字段CLOB或BOLB"; 

1. String轉大字段

//String 轉 clob   
Clob c = new SerialClob(s1.toCharArray()); 
//String 轉 blob    
Blob b = new SerialBlob(s1.getBytes("GBK"));
//也可以這樣不傳字符集名稱，使用系統默認的
//Blob b = new SerialBlob(s1.getBytes());

2. 大字段轉String

//clob 轉 String  
String clobStri = c.getSubString(1, (int) c.length());	
//blob 轉 String      
String blobString = new String(b.getBytes(1, (int) b.length()),"GBK");	
//前面若沒傳入字符集名稱，則這里也不需要傳入，以免出錯
//String blobString = new String(b.getBytes(1, (int) b.length()));        
System.out.println(clobString);        
System.out.println(blobString);

• 轉換函數

public static String convertToString(Object o){if(o == null)return null;if(o instanceof String){return (String)o;}else if(o instanceof Integer){return o.toString();}else if(o instanceof SerializableClob){SerializableClob clob = (SerializableClob) o ;try {return clob.getSubString(1, (int) clob.length());} catch (SQLException e) {throw new RuntimeException(e);}}return o.toString();}

這種數據庫的字段類型轉成Java字段類型的行為，從框架上來說叫做orm(object-relative-model)對象關系模型