尝试根据错误代码捕获Java SQLException separate

Question

我需要根据ErrorCode分隔SQLExceptions。我在catch block中有以下if语句，但是else条件总是打印出来的

catch (SQLException ex) {

      if (ex.getErrorCode() == 28502){
         System.out.println("Username Problem");
      }

      else{
         System.out.println("Other Problem");
      }  

     Logger.getLogger(FirstTimeMainFrame.class.getName()).log(Level.SEVERE, null, ex);

}

实际上，当我在创建DB时输入意外的username时，会抛出以下SQLExceptions

java.sql.SQLException: Failed to create database 'myDB', see the next exception for details.
//rest of exception.
Caused by: ERROR XJ041: Failed to create database 'myDB', see the next exception for details.
//rest of exception.
Caused by: ERROR XBM01: Startup failed due to an exception. See next exception for details
//rest of exception.
Caused by: ERROR 28502: The user name 'AAA.AAA' is not valid.
//rest of exception.

但是我的catch总是打印Other Problem。如何根据上一个ErrorCode分隔不同的SQLExceptions

Answer 1

-已解决-

感谢您对@blm first的评论

技巧是其他即将到来的Exceptions（第一和第二）在其SQLState中有String值，在其ErrorCode中只有数值

SQLException第三链exception既有SQLState又有ErrorCode。我想这就是第一和第二的区别

所以我改变了主意

捕捉块

catch (SQLException se) {

      do {

         if(se.getSQLState().equals("28502")){
            System.out.println("Username Problem");
         }

         else{
            System.out.println("Other Problem");
         }  

      } while ((se = se.getNextException()) != null);

}

输出为

Other Problem
Other Problem
Username Problem

Answer 2

您应该使用捕获的SqlExeption对象的“getCause（）”方法获取原因异常。然后，您可以将结果强制转换为异常并检查其错误代码
检查此项以了解更多信息：Throwable.getCause()

编辑：

SQLException temp = ex;
while(temp.getCause() != null)
{
     temp = (Exception)temp.getCause();
}
//  check if temp is SQLException and if it is check ((SQLException)temp).getErrorCode() == whatever you want