SystemPropertiesTableModel


1   /* ========================================================================
2    * JCommon : a free general purpose class library for the Java(tm) platform
3    * ========================================================================
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5    * (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
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24   * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
25   * in the United States and other countries.]
26   * 
27   * -------------------------------
28   * SystemPropertiesTableModel.java
29   * -------------------------------
30   * (C) Copyright 2000-2004, by Object Refinery Limited.
31   *
32   * Original Author:  David Gilbert (for Object Refinery Limited);
33   * Contributor(s):   -;
34   *
35   * $Id: SystemPropertiesTableModel.java,v 1.5 2005/10/18 13:19:13 mungady Exp $
36   *
37   * Changes (from 26-Oct-2001)
38   * --------------------------
39   * 26-Oct-2001 : Changed package to com.jrefinery.ui (DG);
40   * 28-Feb-2001 : Changed package to com.jrefinery.ui.about (DG);
41   * 15-Mar-2002 : Modified to use a ResourceBundle for elements that require localisation (DG);
42   * 08-Oct-2002 : Fixed errors reported by Checkstyle (DG);
43   *
44   */
45  
46  package org.jfree.ui.about;
47  
48  import java.util.Collections  ;
49  import java.util.Comparator  ;
50  import java.util.Iterator  ;
51  import java.util.List  ;
52  import java.util.Properties  ;
53  import java.util.ResourceBundle  ;
54  
55  import org.jfree.ui.SortableTableModel;
56  
57  /**
58   * A sortable table model containing the system properties.
59   *
60   * @author David Gilbert
61   */
62  public class SystemPropertiesTableModel extends SortableTableModel {
63  
64      /**
65       * Useful class for holding the name and value of a system property.
66       *
67       */
68      protected static class SystemProperty {
69  
70          /** The property name. */
71          private String   name;
72  
73          /** The property value. */
74          private String   value;
75  
76          /**
77           * Standard constructor - builds a new SystemProperty.
78           *
79           * @param name  the property name.
80           * @param value  the property value.
81           */
82          public SystemProperty(final String   name, final String   value) {
83                  this.name = name;
84                  this.value = value;
85          }
86  
87          /**
88           * Returns the property name.
89           *
90           * @return the property name.
91           */
92          public String   getName() {
93              return this.name;
94          }
95  
96          /**
97           * Returns the property value.
98           *
99           * @return the property value.
100          */
101         public String   getValue() {
102             return this.value;
103         }
104 
105     }
106 
107     /**
108      * A class for comparing SystemProperty objects.
109      *
110      */
111     protected static class SystemPropertyComparator implements Comparator   {
112 
113         /** Indicates the sort order. */
114         private boolean ascending;
115 
116         /**
117          * Standard constructor.
118          *
119          * @param ascending  a flag that controls the sort order (ascending or descending).
120          */
121         public SystemPropertyComparator(final boolean ascending) {
122             this.ascending = ascending;
123         }
124 
125         /**
126          * Compares two objects.
127          *
128          * @param o1  the first object.
129          * @param o2  the second object.
130          *
131          * @return an integer that indicates the relative order of the objects.
132          */
133         public int compare(final Object   o1, final Object   o2) {
134 
135             if ((o1 instanceof SystemProperty) && (o2 instanceof SystemProperty)) {
136                 final SystemProperty sp1 = (SystemProperty) o1;
137                 final SystemProperty sp2 = (SystemProperty) o2;
138                 if (this.ascending) {
139                     return sp1.getName().compareTo(sp2.getName());
140                 }
141                 else {
142                     return sp2.getName().compareTo(sp1.getName());
143                 }
144             }
145             else {
146                 return 0;
147             }
148 
149         }
150 
151         /**
152          * Returns <code>true</code> if this object is equal to the specified object, and
153          * <code>false</code> otherwise.
154          *
155          * @param o  the other object.
156          *
157          * @return A boolean.
158          */
159         public boolean equals(final Object   o) {
160             if (this == o) {
161                 return true;
162             }
163             if (!(o instanceof SystemPropertyComparator)) {
164                 return false;
165             }
166 
167             final SystemPropertyComparator systemPropertyComparator = (SystemPropertyComparator) o;
168 
169             if (this.ascending != systemPropertyComparator.ascending) {
170                 return false;
171             }
172 
173             return true;
174         }
175 
176         /**
177          * Returns a hash code value for the object.
178          *
179          * @return the hashcode
180          */
181         public int hashCode() {
182             return (this.ascending ? 1 : 0);
183         }
184     }
185 
186     /** Storage for the properties. */
187     private List   properties;
188 
189     /** Localised name column label. */
190     private String   nameColumnLabel;
191 
192     /** Localised property column label. */
193     private String   valueColumnLabel;
194 
195     /**
196      * Creates a new table model using the properties of the current Java Virtual Machine.
197      */
198     public SystemPropertiesTableModel() {
199 
200         this.properties = new java.util.ArrayList  ();
201         try {
202             final Properties   p = System.getProperties();
203             final Iterator   iterator = p.keySet().iterator();
204             while (iterator.hasNext()) {
205                 final String   name = (String  ) iterator.next();
206                     final String   value = System.getProperty(name);
207                     final SystemProperty sp = new SystemProperty(name, value);
208                     this.properties.add(sp);
209             }
210         }
211         catch (SecurityException   se) {
212             // ignore SecurityExceptions
213         }
214 
215         Collections.sort(this.properties, new SystemPropertyComparator(true));
216 
217         final String   baseName = "org.jfree.ui.about.resources.AboutResources";
218         final ResourceBundle   resources = ResourceBundle.getBundle(baseName);
219 
220         this.nameColumnLabel = resources.getString("system-properties-table.column.name");
221         this.valueColumnLabel = resources.getString("system-properties-table.column.value");
222 
223     }
224 
225     /**
226      * Returns true for the first column, and false otherwise - sorting is only allowed on the
227      * first column.
228      *
229      * @param column  the column index.
230      *
231      * @return true for column 0, and false for all other columns.
232      */
233     public boolean isSortable(final int column) {
234 
235         if (column == 0) {
236             return true;
237         }
238         else {
239             return false;
240         }
241 
242     }
243 
244     /**
245      * Returns the number of rows in the table model (that is, the number of system properties).
246      *
247      * @return the row count.
248      */
249     public int getRowCount() {
250         return this.properties.size();
251     }
252 
253     /**
254      * Returns the number of columns in the table model.  In this case, there are two columns: one
255      * for the property name, and one for the property value.
256      *
257      * @return the column count (always 2 in this case).
258      */
259     public int getColumnCount() {
260         return 2;
261     }
262 
263     /**
264      * Returns the name of the specified column.
265      *
266      * @param column  the column index.
267      *
268      * @return the column name.
269      */
270     public String   getColumnName(final int column) {
271 
272         if (column == 0) {
273             return this.nameColumnLabel;
274         }
275         else {
276             return this.valueColumnLabel;
277         }
278 
279     }
280 
281     /**
282      * Returns the value at the specified row and column.  This method supports the TableModel
283      * interface.
284      *
285      * @param row  the row index.
286      * @param column  the column index.
287      *
288      * @return the value.
289      */
290     public Object   getValueAt(final int row, final int column) {
291 
292         final SystemProperty sp = (SystemProperty) this.properties.get(row);
293         if (column == 0) {
294             return sp.getName();
295         }
296         else {
297             if (column == 1) {
298                 return sp.getValue();
299             }
300             else {
301                 return null;
302             }
303         }
304 
305     }
306 
307     /**
308      * Sorts on the specified column.
309      *
310      * @param column  the column index.
311      * @param ascending  a flag that controls the sort order.
312      *
313      */
314     public void sortByColumn(final int column, final boolean ascending) {
315 
316         if (isSortable(column)) {
317             super.sortByColumn(column, ascending);
318             Collections.sort(this.properties, new SystemPropertyComparator(ascending));
319         }
320 
321     }
322 
323 
324 }
325
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