Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2013 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation * Pawel Pogorzelski - <Pawel.Pogorzelski@pl.ibm.com> - fix for bug 289599 *******************************************************************************/ package org.eclipse.jface.preference; import org.eclipse.core.commands.common.EventManager; import org.eclipse.core.runtime.Assert; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintStream; import java.io.PrintWriter; import java.util.Properties; import java.util.Set; /** * A concrete preference store implementation based on an internal * <code>java.util.Properties</code> object, with support for persisting the * non-default preference values to files or streams. * <p> * This class was not designed to be subclassed. * </p> * * @see IPreferenceStore * @noextend This class is not intended to be subclassed by clients. */ public class PreferenceStore extends EventManager implements IPreferenceStore { /** * The mapping from preference name to preference value (represented as * strings). */ private Properties properties; /** * The mapping from preference name to default preference value (represented * as strings); <code>null</code> if none. */ private Properties defaultProperties; /** * Indicates whether a value as been changed by <code>setToDefault</code> * or <code>setValue</code>; initially <code>false</code>. */ private boolean dirty = false; /** * The file name used by the <code>load</code> method to load a property * file. This filename is used to save the properties file when * <code>save</code> is called. */ private String filename; /** * Creates an empty preference store. * <p> * Use the methods <code>load(InputStream)</code> and * <code>save(InputStream)</code> to load and store this preference store. * </p> * * @see #load(InputStream) * @see #save(OutputStream, String) */ public PreferenceStore() { defaultProperties = new Properties(); properties = new Properties(defaultProperties); } /** * Creates an empty preference store that loads from and saves to the a * file. * <p> * Use the methods <code>load()</code> and <code>save()</code> to load * and store this preference store. * </p> * * @param filename * the file name * @see #load() * @see #save() */ public PreferenceStore(String filename) { this(); Assert.isNotNull(filename); this.filename = filename; } // @Override // public void addPropertyChangeListener(IPropertyChangeListener listener) { // addListenerObject(listener); // } @Override public boolean contains(String name) { return (properties.containsKey(name) || defaultProperties.containsKey(name)); } @Override public void firePropertyChangeEvent(String name, Object oldValue, Object newValue) { // final Object[] finalListeners = getListeners(); // // Do we need to fire an event. // if (finalListeners.length > 0 // && (oldValue == null || !oldValue.equals(newValue))) { // final PropertyChangeEvent pe = new PropertyChangeEvent(this, name, // oldValue, newValue); // for (int i = 0; i < finalListeners.length; ++i) { // final IPropertyChangeListener l = (IPropertyChangeListener) finalListeners[i]; // SafeRunnable.run(new SafeRunnable(JFaceResources // .getString("PreferenceStore.changeError")) { //$NON-NLS-1$ // @Override // public void run() { // l.propertyChange(pe); // } // }); // } // } } @Override public boolean getBoolean(String name) { return getBoolean(properties, name); } /** * Helper function: gets boolean for a given name. * * @param p * @param name * @return boolean */ private boolean getBoolean(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) { return BOOLEAN_DEFAULT_DEFAULT; } if (value.equals(TRUE)) { return true; } return false; } @Override public boolean getDefaultBoolean(String name) { return getBoolean(defaultProperties, name); } @Override public double getDefaultDouble(String name) { return getDouble(defaultProperties, name); } @Override public float getDefaultFloat(String name) { return getFloat(defaultProperties, name); } @Override public int getDefaultInt(String name) { return getInt(defaultProperties, name); } @Override public long getDefaultLong(String name) { return getLong(defaultProperties, name); } @Override public String getDefaultString(String name) { return getString(defaultProperties, name); } @Override public double getDouble(String name) { return getDouble(properties, name); } /** * Helper function: gets double for a given name. * * @param p * @param name * @return double */ private double getDouble(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) { return DOUBLE_DEFAULT_DEFAULT; } double ival = DOUBLE_DEFAULT_DEFAULT; try { ival = new Double(value).doubleValue(); } catch (NumberFormatException e) { } return ival; } @Override public float getFloat(String name) { return getFloat(properties, name); } /** * Helper function: gets float for a given name. * * @param p * @param name * @return float */ private float getFloat(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) { return FLOAT_DEFAULT_DEFAULT; } float ival = FLOAT_DEFAULT_DEFAULT; try { ival = new Float(value).floatValue(); } catch (NumberFormatException e) { } return ival; } @Override public int getInt(String name) { return getInt(properties, name); } /** * Helper function: gets int for a given name. * * @param p * @param name * @return int */ private int getInt(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) { return INT_DEFAULT_DEFAULT; } int ival = 0; try { ival = Integer.parseInt(value); } catch (NumberFormatException e) { } return ival; } @Override public long getLong(String name) { return getLong(properties, name); } /** * Helper function: gets long for a given name. * * @param p * the properties storage (may be <code>null</code>) * @param name * the name of the property * @return the long or a default value of if: * <ul> * <li>properties storage is <code>null</code></li> * <li>property is not found</li> * <li>property value is not a number</li> * </ul> * @see IPreferenceStore#LONG_DEFAULT_DEFAULT */ private long getLong(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) { return LONG_DEFAULT_DEFAULT; } long ival = LONG_DEFAULT_DEFAULT; try { ival = Long.parseLong(value); } catch (NumberFormatException e) { } return ival; } @Override public String getString(String name) { return getString(properties, name); } /** * Helper function: gets string for a given name. * * @param p * the properties storage (may be <code>null</code>) * @param name * the name of the property * @return the value or a default value of if: * <ul> * <li>properties storage is <code>null</code></li> * <li>property is not found</li> * <li>property value is not a number</li> * </ul> * @see IPreferenceStore#STRING_DEFAULT_DEFAULT */ private String getString(Properties p, String name) { String value = p != null ? p.getProperty(name) : null; if (value == null) { return STRING_DEFAULT_DEFAULT; } return value; } @Override public boolean isDefault(String name) { return (!properties.containsKey(name) && defaultProperties.containsKey(name)); } /** * Prints the contents of this preference store to the given print stream. * * @param out * the print stream */ public void list(PrintStream out) { properties.list(out); } /** * Prints the contents of this preference store to the given print writer. * * @param out * the print writer */ public void list(PrintWriter out) { properties.list(out); } /** * Loads this preference store from the file established in the constructor * <code>PreferenceStore(java.lang.String)</code> (or by * <code>setFileName</code>). Default preference values are not affected. * * @exception IOException * if there is a problem loading this store */ public void load() throws IOException { if (filename == null) { throw new IOException("File name not specified");//$NON-NLS-1$ } FileInputStream in = new FileInputStream(filename); load(in); in.close(); } /** * Loads this preference store from the given input stream. Default * preference values are not affected. * * @param in * the input stream * @exception IOException * if there is a problem loading this store */ public void load(InputStream in) throws IOException { properties.load(in); dirty = false; } @Override public boolean needsSaving() { return dirty; } /** * Returns an enumeration of all preferences known to this store which have * current values other than their default value. * * @return an array of preference names */ public String[] preferenceNames() { Set<String> set = properties.stringPropertyNames(); return set.toArray(new String[set.size()]); } @Override public void putValue(String name, String value) { String oldValue = getString(name); if (oldValue == null || !oldValue.equals(value)) { setValue(properties, name, value); dirty = true; } } // @Override // public void removePropertyChangeListener(IPropertyChangeListener listener) { // removeListenerObject(listener); // } // /** // * Saves the non-default-valued preferences known to this preference store // * to the file from which they were originally loaded. // * // * @exception IOException // * if there is a problem saving this store // */ // @Override // public void save() throws IOException { // if (filename == null) { // throw new IOException("File name not specified");//$NON-NLS-1$ // } // FileOutputStream out = null; // try { // out = new FileOutputStream(filename); // save(out, null); // } finally { // if (out != null) { // out.close(); // } // } // } /** * Saves this preference store to the given output stream. The given string * is inserted as header information. * * @param out * the output stream * @param header * the header * @exception IOException * if there is a problem saving this store */ public void save(OutputStream out, String header) throws IOException { properties.store(out, header); dirty = false; } @Override public void setDefault(String name, double value) { setValue(defaultProperties, name, value); } @Override public void setDefault(String name, float value) { setValue(defaultProperties, name, value); } @Override public void setDefault(String name, int value) { setValue(defaultProperties, name, value); } @Override public void setDefault(String name, long value) { setValue(defaultProperties, name, value); } @Override public void setDefault(String name, String value) { setValue(defaultProperties, name, value); } @Override public void setDefault(String name, boolean value) { setValue(defaultProperties, name, value); } /** * Sets the name of the file used when loading and storing this preference * store. * <p> * Afterward, the methods <code>load()</code> and <code>save()</code> * can be used to load and store this preference store. * </p> * * @param name * the file name * @see #load() * @see #save() */ public void setFilename(String name) { filename = name; } @Override public void setToDefault(String name) { if (!properties.containsKey(name)) return; Object oldValue = properties.get(name); properties.remove(name); dirty = true; Object newValue = null; if (defaultProperties != null) { newValue = defaultProperties.get(name); } firePropertyChangeEvent(name, oldValue, newValue); } @Override public void setValue(String name, double value) { double oldValue = getDouble(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, new Double(oldValue), new Double(value)); } } @Override public void setValue(String name, float value) { float oldValue = getFloat(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, new Float(oldValue), new Float(value)); } } @Override public void setValue(String name, int value) { int oldValue = getInt(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, new Integer(oldValue), new Integer(value)); } } @Override public void setValue(String name, long value) { long oldValue = getLong(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, new Long(oldValue), new Long(value)); } } @Override public void setValue(String name, String value) { String oldValue = getString(name); if (oldValue == null || !oldValue.equals(value)) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, oldValue, value); } } @Override public void setValue(String name, boolean value) { boolean oldValue = getBoolean(name); if (oldValue != value) { setValue(properties, name, value); dirty = true; firePropertyChangeEvent(name, oldValue ? Boolean.TRUE : Boolean.FALSE, value ? Boolean.TRUE : Boolean.FALSE); } } /** * Helper method: sets value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, double value) { Assert.isTrue(p != null); p.put(name, Double.toString(value)); } /** * Helper method: sets value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, float value) { Assert.isTrue(p != null); p.put(name, Float.toString(value)); } /** * Helper method: sets value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, int value) { Assert.isTrue(p != null); p.put(name, Integer.toString(value)); } /** * Helper method: sets the value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, long value) { Assert.isTrue(p != null); p.put(name, Long.toString(value)); } /** * Helper method: sets the value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, String value) { Assert.isTrue(p != null && value != null); p.put(name, value); } /** * Helper method: sets the value for a given name. * * @param p * @param name * @param value */ private void setValue(Properties p, String name, boolean value) { Assert.isTrue(p != null); p.put(name, value == true ? TRUE : FALSE); } }