This chapter describes how your Java program can deal with its
immediate surroundings, what we call the runtime
. In one sense, everything you do in a Java
program using almost any Java API involves the environment. Here we
focus more narrowly on things that directly surround your program.
Along the way we’ll meet the
which knows a lot about our system.
Two other runtime classes deserve brief mention. The first,
java.lang.Runtime, lies behind many of the methods
System.exit( ), for example, just calls
Runtime.exit( ). This is technically part of “the
environment,” but the only time we use it directly is to run
other programs, which is covered in Section 26.2. The
java.awt.Toolkit object is also part of the
environment and is discussed in Chapter 12.