I wrote the Io class to make console input and output easier.  It may be 
found on the disk included with the text.  The Io class methods (all 
static) are:
      public static int readInt(String prompt)
      public static int readDouble(String prompt)
      public static int readLong(String prompt)
      public static void print$(double d)
      public static void println$(double d)
      public static void print(double d, int n)
      public static void println(double d, int n)
      public static char readChar(String prompt)
      public static String readString(String prompt)

The Io class is found in the package iopack.  To use these methods use 
the line
       import iopack.Io;

at the beginning of the program, and make sure the iopack directory is on 
the class path.  IDE's have their own menus to add packages to the 
classpath.  Using the JDK or SDK from Sun, the easiest way to get iopack 
in the classpath is to copy it into the current directory, making iopack 
a subdirectory.
    Another approach is the add the classpath option to the javac and 
java commands.  For example to compile and execute the program Inherit.java

   in Java 1.1 using Windows
javac -classpath .;a:\gittleman;c:\jdk1.1.8\lib\classes.zip  Inherit.java
java -classpath .;a:\gittleman;c:\jad1.1.8\lib\classes.zip  Inherit

   in Java 2 (1.2) using Windows
javac -classpath .;a:\gittleman Inherit.java
java -classpath .;a:\gittleman Inherit

where the directory iopack is found in a:\gittleman.
    The difference between 1.1 and Java 2 occurs because the classpath in 
Java 2 only refers to user classes, not system classes.

It is also possible to set the classpath environment variable.