Sto scrivendo un'applicazione Java utilizzando l'IDE NetBeans 3.5.1 e la jdk 1.4.2 e nonostante non usi nessun package di java.net, java.lang, .. mi viene in compilazione una miriade di errori del tipo:

java/net/URI.java [2.572:1] warning: as of release 1.4, assert is a keyword, and may not be used as an identifier
assert false;
^
java/net/URI.java [2.572:1] not a statement
assert false;
^
java/net/URI.java [2.572:1] ';' exp

...

java/lang/FloatingDecimal.java [813:1] warning: as of release 1.4, assert is a keyword, and may not be used as an identifier
assert q < 10 : q; // excessively large digit
^
java/lang/FloatingDecimal.java [813:1] ';' expected
assert q < 10 : q; // excessively large digit

...

java/nio/DirectByteBuffer.java [307:1] warning: as of release 1.4, assert is a keyword, and may not be used as an identifier
assert (pos <= lim);
^
java/nio/DirectByteBuffer.java [332:1] warning: as of release 1.4, assert is a keyword, and may not be used as an identifier
assert (pos <= lim);

...

Da cosa può dipendere, visto che tempo fa funzionava tutto ok?

Ciao