Controlling javac optimization when compiling

Could someone tell me how to control the optimization performed by javac? Prior to JDK 1.5, javac had a command-line optimization flag, but nothing like it is documented for 1.5.

I ask because I've been using Eclipse 3.1 to debug JDK-compiled Java and Java-via-JSP classes, mostly like a dream. But occasionally I can't step into code selections, usually the very ones causing an Exception - the debugger jumps straight to the Exception handling code. I assume this is because the compiler has done some optimization. btw, I'm compiling using JDK 1.5.0 javac, not whatever Eclipse/Ant would give me.

Thanks in advance.

Jon

[650 byte] By [JonRWoodsa] at [2007-10-2 4:48:57]