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| • |
To
use a library we must import it:
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import
java.util.*;
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– |
This
brings in the entire utility library
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And,
it manages the namespace since it only brings in those classes that
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are
requested
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When
we have multiple source files, each file should have a public class that
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is
the same name as the file (including capitalization but excluding the file
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extension)
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Multiple
files can create a “package”
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If
you place package list_library;
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As
the first non-commented line in your file – you are saying that this
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compilation
unit is part of a larger library that you are building
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SO,
there need not be a public class in each file since we are part of a
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larger
unit.
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And,
then such packages can be imported!
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If
there are collisions in the libraries and packages that you import, then
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Java
will require you to explicitly specify the “classpath” from which the
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class
exists
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