systempropertiestablemodel.java

这是一个segy数据显示程序

/* ========================================================================
 * JCommon : a free general purpose class library for the Java(tm) platform
 * ========================================================================
 *
 * (C) Copyright 2000-2004, by Object Refinery Limited and Contributors.
 * 
 * Project Info:  http://www.jfree.org/jcommon/index.html
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
 * in the United States and other countries.]
 * 
 * -------------------------------
 * SystemPropertiesTableModel.java
 * -------------------------------
 * (C) Copyright 2000-2004, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * $Id: SystemPropertiesTableModel.java,v 1.11 2004/04/26 19:15:45 taqua Exp $
 *
 * Changes (from 26-Oct-2001)
 * --------------------------
 * 26-Oct-2001 : Changed package to com.jrefinery.ui (DG);
 * 28-Feb-2001 : Changed package to com.jrefinery.ui.about (DG);
 * 15-Mar-2002 : Modified to use a ResourceBundle for elements that require localisation (DG);
 * 08-Oct-2002 : Fixed errors reported by Checkstyle (DG);
 *
 */

package org.jfree.ui.about;

import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
import java.util.Properties;
import java.util.ResourceBundle;

import org.jfree.ui.SortableTableModel;

/**
 * A sortable table model containing the system properties.
 *
 */
public class SystemPropertiesTableModel extends SortableTableModel {

    /** Storage for the properties. */
    private List properties;

    /** Localised name column label. */
    private String nameColumnLabel;

    /** Localised property column label. */
    private String valueColumnLabel;

    /**
     * Creates a new table model using the properties of the current Java Virtual Machine.
     */
    public SystemPropertiesTableModel() {

        this.properties = new java.util.ArrayList();
        final Properties p = System.getProperties();
        final Iterator iterator = p.keySet().iterator();
        while (iterator.hasNext()) {
            final String name = (String) iterator.next();
            final String value = System.getProperty(name);
            final SystemProperty sp = new SystemProperty(name, value);
            this.properties.add(sp);
        }

        Collections.sort(this.properties, new SystemPropertyComparator(true));

        final String baseName = "org.jfree.ui.about.resources.AboutResources";
        final ResourceBundle resources = ResourceBundle.getBundle(baseName);

        this.nameColumnLabel = resources.getString("system-properties-table.column.name");
        this.valueColumnLabel = resources.getString("system-properties-table.column.value");

    }

    /**
     * Returns true for the first column, and false otherwise - sorting is only allowed on the
     * first column.
     *
     * @param column  the column index.
     *
     * @return true for column 0, and false for all other columns.
     */
    public boolean isSortable(final int column) {

        if (column == 0) {
            return true;
        }
        else {
            return false;
        }

    }

    /**
     * Returns the number of rows in the table model (that is, the number of system properties).
     *
     * @return the row count.
     */
    public int getRowCount() {
        return this.properties.size();
    }

    /**
     * Returns the number of columns in the table model.  In this case, there are two columns: one
     * for the property name, and one for the property value.
     *
     * @return the column count (always 2 in this case).
     */
    public int getColumnCount() {
        return 2;
    }

    /**
     * Returns the name of the specified column.
     *
     * @param column  the column index.
     *
     * @return the column name.
     */
    public String getColumnName(final int column) {

        if (column == 0) {
            return this.nameColumnLabel;
        }
        else {
            return this.valueColumnLabel;
        }

    }

    /**
     * Returns the value at the specified row and column.  This method supports the TableModel
     * interface.
     *
     * @param row  the row index.
     * @param column  the column index.
     *
     * @return the value.
     */
    public Object getValueAt(final int row, final int column) {

        final SystemProperty sp = (SystemProperty) this.properties.get(row);
        if (column == 0) {
            return sp.getName();
        }
        else {
            if (column == 1) {
                return sp.getValue();
            }
            else {
                return null;
            }
        }

    }

    /**
     * Sorts on the specified column.
     *
     * @param column  the column index.
     * @param ascending  a flag that controls the sort order.
     *
     */
    public void sortByColumn(final int column, final boolean ascending) {

        if (isSortable(column)) {
            super.sortByColumn(column, ascending);
            Collections.sort(this.properties, new SystemPropertyComparator(ascending));
        }

    }


}

/**
 * Useful class for holding the name and value of a system property.
 *
 */
class SystemProperty {

    /** The property name; */
    private String name;

    /** The property value; */
    private String value;

    /**
     * Standard constructor - builds a new SystemProperty.
     *
     * @param name  the property name.
     * @param value  the property value.
     */
    public SystemProperty(final String name, final String value) {
            this.name = name;
            this.value = value;
    }

    /**
     * Returns the property name.
     *
     * @return the property name.
     */
    public String getName() {
        return this.name;
    }

    /**
     * Returns the property value.
     *
     * @return the property value.
     */
    public String getValue() {
        return this.value;
    }

}

/**
 * A class for comparing SystemProperty objects.
 *
 */
class SystemPropertyComparator implements Comparator {

    /** Indicates the sort order. */
    private boolean ascending;

    /**
     * Standard constructor.
     *
     * @param ascending  a flag that controls the sort order (ascending or descending).
     */
    public SystemPropertyComparator(final boolean ascending) {
        this.ascending = ascending;
    }

    /**
     * Compares two objects.
     *
     * @param o1  the first object.
     * @param o2  the second object.
     *
     * @return an integer that indicates the relative order of the objects.
     */
    public int compare(final Object o1, final Object o2) {

        if ((o1 instanceof SystemProperty) && (o2 instanceof SystemProperty)) {
            final SystemProperty sp1 = (SystemProperty) o1;
            final SystemProperty sp2 = (SystemProperty) o2;
            if (this.ascending) {
                return sp1.getName().compareTo(sp2.getName());
            }
            else {
                return sp2.getName().compareTo(sp1.getName());
            }
        }
        else {
            return 0;
        }

    }

    /**
     * Returns <code>true</code> if this object is equal to the specified object, and
     * <code>false</code> otherwise.
     *
     * @param o  the other object.
     *
     * @return A boolean.
     */
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        }
        if (!(o instanceof SystemPropertyComparator)) {
            return false;
        }

        final SystemPropertyComparator systemPropertyComparator = (SystemPropertyComparator) o;

        if (this.ascending != systemPropertyComparator.ascending) {
            return false;
        }

        return true;
    }

    /**
     * Returns a hash code value for the object.
     *
     * @return the hashcode
     */
    public int hashCode() {
        return (this.ascending ? 1 : 0);
    }
}