Convert checked exception into unchecked exception

Question

Hi friends
I am little confused, When deciding on checked exceptions vs. unchecked exceptions. I went through the net. they are telling that
Use checked exceptions when the client code can take some useful recovery action based on information in exception. Use unchecked exception when client code cannot do anything.
Here what is the client code. which is the best way is checked exception good or is unchecked exception good or shall i simply tell catch(Exception e){...} or do i have to tell the particular exception like catch(SQLException) {..} instead of mentioning catch(excetpion){....}. I am so much confused...
Could you please tell me how to convert this code from checked exception into unchecked exception.
Connection con = null;
try {
     Class.forName("com.mysql.jdbc.Driver").newInstance();
     con = DriverManager.getConnection("jdbc:mysql://localhost:3306/test",
     "root", "sheik");
     if(!con.isClosed())
     System.out.println("Successfully connected to " +
     "MySQL server using TCP/IP...");
     PreparedStatement ps = con.prepareStatement("DELETE FROM EMPLOYEE WHERE ID=?");
     ps.setInt(1, 3);     
     System.out.println(ps.executeUpdate());
     } catch(Exception e) {
     System.err.println("Exception: " + e.getMessage());
     } finally {
     try {
     if(con != null)
     con.close();
     } catch(SQLException e) {
          System.out.println(e);
Thanks and Regards
Sherin Pooja

Answer 1

pierrot_2 wrote:
I think the words CHECKED and UNCHECKED are misleading.How so? Checked exceptions are those that are checked for by the compiler--requiring either catch or declare, and unchecked exceptions are those that the compiler doesn't check for and hence can be thrown anywhere without a catch or declare.
When a program can't deal with a situation at all, subclasses of <tt>Error</tt> are thrown and the program should terminate. When a program should continue to run, despite an anomaly of some sort, then programs should throw subclasses of <tt>Exception</tt>.No.
When there's a normal exceptional condition that can't be avoided simply by good coding--loss of network connection, disk full, insufficient permissions for an operatiion, and so on--throw a checked exception, that is, a subclass of Exception that is not a subclass of RuntimeException, such as IOExceptoin.
When there's a bug in your code, or in the caller of your code, or in some other code that you use, such as not ensuring preconditions are met, throw RuntimeException or a subclass. These are all unchecked. You generally do not catch these except at major layer boundaries.
When there's an internal error that the JVM has a good chance of not being able to recover from, such as running out of memory, Error or one of its subclasses is thrown. These are also unchecked, and it's pretty rare to explicitly throw one of these from code that you write. You generally do not catch these, except at major layer boundaries, and even then, probably in fewer situations than when you'd catch RuntimeException.