say I have the following
try{
//something
}catch(Exception generic){
//catch all
}catch(SpecificException se){
//catch specific exception only
}
What would happen when it comes across SpecificException ? Does it catch it as a generic exception first, and then catch the specificexception ?
Or does it only catch SpecificException while ignoring generic exceptions.
I don't want both generic and specificexception being caught.
This won't compile. You'll be told that the specific exception block isn't reachable.
You have to have the more specific exception catch block first, followed by the general one.
try
{
//something
}
catch(SpecificException se)
{
//catch specific exception only
}
catch(Exception generic)
{
//catch all
}
No. All exceptions would be caught by the first block. The second will never be reached (which the compiler recognizes, leading to an error due to unreachable code). If you want to treat SpecificException specifically, you have to do it the other way round:
}catch(SpecificException se){
//catch specific exception only
}catch(Exception generic){
//catch all
}
Then SpecificException will be caught by the first block, and all others by the second.
.class file is created, so no code to run.This does not compile with eclipse compiler:
Unreachable catch block for IOException. It is already handled by the catch block for Exception
So define them the other way. Only the specific one will be caught.
The catch blocks are tried in order, and the first one that matches the type of the exception is executed. Since Exception is the superclass of all exception types, it will always be executed in this instance and the specific cases will never be executed. In fact the compiler is smart enough to notice this and raise a compilation error.
Just reorder the catch clauses.
As a side note, the only way to have both catch blocks called is to use nested exceptions.
try {
try{
//something
}catch(SpecificException se){
//catch specific exception only
throw se;
}
}catch(Exception generic){
//catch all
}
My proposition - catch SQLException and check code.
try {
getConnectionSYS(dbConfigFile, properties);
} catch (SQLException e){
if (e.getErrorCode()==1017){
getConnectionUSER(dbConfigFile, properties);
} else {
throw e;
}
}
