/*******************************************************************************
* Companion code for the book "Introduction to Software Design with Java",
* 2nd edition by Martin P. Robillard.
*
* Copyright (C) 2022 by Martin P. Robillard
*
* This code is licensed under a Creative Commons
* Attribution-NonCommercial-NoDerivatives 4.0 International License.
*
* See http://creativecommons.org/licenses/by-nc-nd/4.0/
*
*******************************************************************************/
package e2.chapter7;
/**
* Decorator that prints the card drawn on the console.
*/
public class LoggingDecorator extends AbstractDecorator {
public LoggingDecorator(CardSource pElement) {
super(pElement);
}
@Override
public Card draw() {
Card card = super.draw();
System.out.println(String.format("Draws %s", card));
return card;
}
}System class contains several useful class fields
and methods. It cannot be instantiated.
Among the facilities provided by the System class
are standard input, standard output, and error output streams;
access to externally defined properties and environment
variables; a means of loading files and libraries; and a utility
method for quickly copying a portion of an array.System class contains several useful class fields
and methods. It cannot be instantiated.
Among the facilities provided by the System class
are standard input, standard output, and error output streams;
access to externally defined properties and environment
variables; a means of loading files and libraries; and a utility
method for quickly copying a portion of an array.Here it can be observed that the behavior of the decorated element is accessed via a call to the delegating method in the super class, not by accessing the decorated element directly and calling a method on it.
Here it can be observed that the behavior of the decorated element is accessed via a call to the delegating method in the super class, not by accessing the decorated element directly and calling a method on it.
The locale always used is the one returned by Locale.getDefault(Locale.Category) with
FORMAT category specified.
format - A format stringargs - Arguments referenced by the format specifiers in the format
string. If there are more arguments than format specifiers, the
extra arguments are ignored. The number of arguments is
variable and may be zero. The maximum number of arguments is
limited by the maximum dimension of a Java array as defined by
The Java Virtual Machine Specification.
The behaviour on a
null argument depends on the conversion.IllegalFormatException - If a format string contains an illegal syntax, a format
specifier that is incompatible with the given arguments,
insufficient arguments given the format string, or other
illegal conditions. For specification of all possible
formatting errors, see the Details section of the
formatter class specification.String class represents character strings. All
string literals in Java programs, such as "abc", are
implemented as instances of this class.
String class represents character strings. All
string literals in Java programs, such as "abc", are
implemented as instances of this class.
Strings are constant; their values cannot be changed after they are created. String buffers support mutable strings. Because String objects are immutable they can be shared. For example:
String str = "abc";
is equivalent to:
char data[] = {'a', 'b', 'c'};
String str = new String(data);
Here are some more examples of how strings can be used:
System.out.println("abc");
String cde = "cde";
System.out.println("abc" + cde);
String c = "abc".substring(2, 3);
String d = cde.substring(1, 2);
The class String includes methods for examining
individual characters of the sequence, for comparing strings, for
searching strings, for extracting substrings, and for creating a
copy of a string with all characters translated to uppercase or to
lowercase. Case mapping is based on the Unicode Standard version
specified by the Character class.
The Java language provides special support for the string concatenation operator ( + ), and for conversion of other objects to strings. For additional information on string concatenation and conversion, see The Java Language Specification.
Unless otherwise noted, passing a null argument to a constructor
or method in this class will cause a NullPointerException to be
thrown.
A String represents a string in the UTF-16 format
in which supplementary characters are represented by surrogate
pairs (see the section Unicode
Character Representations in the Character class for
more information).
Index values refer to char code units, so a supplementary
character uses two positions in a String.
The String class provides methods for dealing with
Unicode code points (i.e., characters), in addition to those for
dealing with Unicode code units (i.e., char values).
Unless otherwise noted, methods for comparing Strings do not take locale
into account. The Collator class provides methods for
finer-grain, locale-sensitive String comparison.
javac compiler
may implement the operator with StringBuffer, StringBuilder,
or java.lang.invoke.StringConcatFactory depending on the JDK version. The
implementation of string conversion is typically through the method toString,
defined by Object and inherited by all classes in Java.print(String) and then
println().print(String) and then
println().x - The String to be printed.Console.charset() if the Console exists,
stdout.encoding otherwise.
Console.charset() if the Console exists,
stdout.encoding otherwise.
For simple stand-alone Java applications, a typical way to write a line of output data is:
System.out.println(data)
See the println methods in class PrintStream.