//: Map1.java
//////////////////////////////////////////////////
// Copyright (c) Bruce Eckel, 1998
// Source code file from the book "Thinking in Java"
// All rights reserved EXCEPT as allowed by the
// following statements: You can freely use this file
// for your own work (personal or commercial),
// including modifications and distribution in
// executable form only. Permission is granted to use
// this file in classroom situations, including its
// use in presentation materials, as long as the book
// "Thinking in Java" is cited as the source.
// Except in classroom situations, you cannot copy
// and distribute this code; instead, the sole
// distribution point is http://www.BruceEckel.com
// (and official mirror sites) where it is
// freely available. You cannot remove this
// copyright and notice. You cannot distribute
// modified versions of the source code in this
// package. You cannot use this file in printed
// media without the express permission of the
// author. Bruce Eckel makes no representation about
// the suitability of this software for any purpose.
// It is provided "as is" without express or implied
// warranty of any kind, including any implied
// warranty of merchantability, fitness for a
// particular purpose or non-infringement. The entire
// risk as to the quality and performance of the
// software is with you. Bruce Eckel and the
// publisher shall not be liable for any damages
// suffered by you or any third party as a result of
// using or distributing software. In no event will
// Bruce Eckel or the publisher be liable for any
// lost revenue, profit, or data, or for direct,
// indirect, special, consequential, incidental, or
// punitive damages, however caused and regardless of
// the theory of liability, arising out of the use of
// or inability to use software, even if Bruce Eckel
// and the publisher have been advised of the
// possibility of such damages. Should the software
// prove defective, you assume the cost of all
// necessary servicing, repair, or correction. If you
// think you've found an error, please email all
// modified files with clearly commented changes to:
// Bruce@EckelObjects.com. (Please use the same
// address for non-code errors found in the book.)
/////////////////////////////////////////////////
// Things you can do with Maps
package c08.newcollections;
import java.util.*;
public class Map1 {
public final static String[][] testData1 = {
{ "Happy", "Cheerful disposition" },
{ "Sleepy", "Prefers dark, quiet places" },
{ "Grumpy", "Needs to work on attitude" },
{ "Doc", "Fantasizes about advanced degree"},
{ "Dopey", "'A' for effort" },
{ "Sneezy", "Struggles with allergies" },
{ "Bashful", "Needs self-esteem workshop"},
};
public final static String[][] testData2 = {
{ "Belligerent", "Disruptive influence" },
{ "Lazy", "Motivational problems" },
{ "Comatose", "Excellent behavior" }
};
public static Map fill(Map m, Object[][] o) {
for(int i = 0; i < o.length; i++)
m.put(o[i][0], o[i][1]);
return m;
}
// Producing a Set of the keys:
public static void printKeys(Map m) {
System.out.print("Size = " + m.size() +", ");
System.out.print("Keys: ");
Collection1.print(m.keySet());
}
// Producing a Collection of the values:
public static void printValues(Map m) {
System.out.print("Values: ");
Collection1.print(m.values());
}
// Iterating through Map.Entry objects (pairs):
public static void print(Map m) {
Collection entries = m.entries();
Iterator it = entries.iterator();
while(it.hasNext()) {
Map.Entry e = (Map.Entry)it.next();
System.out.println("Key = " + e.getKey() +
", Value = " + e.getValue());
}
}
public static void test(Map m) {
fill(m, testData1);
// Map has 'Set' behavior for keys:
fill(m, testData1);
printKeys(m);
printValues(m);
print(m);
String key = testData1[4][0];
String value = testData1[4][1];
System.out.println("m.containsKey(\"" + key +
"\"): " + m.containsKey(key));
System.out.println("m.get(\"" + key + "\"): "
+ m.get(key));
System.out.println("m.containsValue(\""
+ value + "\"): " +
m.containsValue(value));
Map m2 = fill(new TreeMap(), testData2);
m.putAll(m2);
printKeys(m);
m.remove(testData2[0][0]);
printKeys(m);
m.clear();
System.out.println("m.isEmpty(): "
+ m.isEmpty());
fill(m, testData1);
// Operations on the Set change the Map:
m.keySet().removeAll(m.keySet());
System.out.println("m.isEmpty(): "
+ m.isEmpty());
}
public static void main(String args[]) {
System.out.println("Testing HashMap");
test(new HashMap());
System.out.println("Testing TreeMap");
test(new TreeMap());
}
} ///:~ |