Java tips, techniques, and sample code. These are for your convenience to read. Note, however, the copyright from SUN .
For currently available JDC Newsletters, see JDC Newsletter archives and also the Technical Articles Also, SUN has an archive page of the tips

JDC TechTips Vol. 2 No. 2 - September 15, 1998: Covering finally clauses and using synchronized statements.

JDC Tech Tips, Special Edition - September 9, 1998: Tips on debugging Java language applications.

JDC TechTips No. 1 - July 22, 1998 Filter Streams and Default Constructors

June 23, 1998 Covering string tokenizing and the enumeration interface.

May 21, 1998 Including how-to information on creating temporary files to hold transient information, and using resource bundles in internationalization.

April 21, 1998 Using Java Collections and unpacking Zip Files.

March 16, 1998 Javadoc. Using Hashtable, Definite Assignment

February 17, 1998: Program assertions,and serialization and transient values.

January 20, 1998: String versus StringBuffer and using javap with .class files

December 16, 1997: Performance and reflection, also known as introspection

November 18, 1997: ScrollPane, faster I/O, and class literals

October 21, 1997: Specifying Menu Shortcuts, Command Dispatching: Java and C/C++ Compared

September 24, 1997: Java Printing, Global Variables

September 3, 1997: Using JAR Files for Archiving, Performance Tip: Garbage Collection