import java.io.File; import java.util.Hashtable; import java.util.Enumeration; import javax.swing.*; import javax.swing.filechooser.*;public class MyFileFilter extends FileFilter { private static String TYPE_UNKNOWN = "Type Unknown"; private static String HIDDEN_FILE = "Hidden File"; private Hashtable filters = null; private String description = null; private String fullDescription = null; private boolean useExtensionsInDescription = true; /** * Creates a file filter. If no filters are added, then all * files are accepted. * * @see #addExtension */ public MyFileFilter() { this.filters = new Hashtable(); } /** * Creates a file filter that accepts files with the given extension. * Example: new ExampleFileFilter("jpg"); * * @see #addExtension */ public MyFileFilter(String extension) { this(extension,null); } /** * Creates a file filter that accepts the given file type. * Example: new ExampleFileFilter("jpg", "JPEG Image Images"); * * Note that the "." before the extension is not needed. If * provided, it will be ignored. * * @see #addExtension */ public MyFileFilter(String extension, String description) { this(); if(extension!=null) addExtension(extension); if(description!=null) setDescription(description); } /** * Creates a file filter from the given string array. * Example: new ExampleFileFilter(String {"gif", "jpg"}); * * Note that the "." before the extension is not needed adn * will be ignored. * * @see #addExtension */ public MyFileFilter(String[] filters) { this(filters, null); } /** * Creates a file filter from the given string array and description. * Example: new ExampleFileFilter(String {"gif", "jpg"}, "Gif and JPG Images"); * * Note that the "." before the extension is not needed and will be ignored. * * @see #addExtension */ public MyFileFilter(String[] filters, String description) { this(); for (int i = 0; i < filters.length; i++) { // add filters one by one addExtension(filters[i]); } if(description!=null) setDescription(description); } /** * Return true if this file should be shown in the directory pane, * false if it shouldn't. * * Files that begin with "." are ignored. * * @see #getExtension * @see FileFilter#accepts */ public boolean accept(File f) { if(f != null) { if(f.isDirectory()) { return true; } String extension = getExtension(f); if(extension != null && filters.get(getExtension(f)) != null) { return true; } } return false; } /** * Return the extension portion of the file's name . * * @see #getExtension * @see FileFilter#accept */ public String getExtension(File f) { if(f != null) { String filename = f.getName(); int i = filename.lastIndexOf('.'); if(i>0 && i<filename.length()-1) { return filename.substring(i+1).toLowerCase(); }; } return null; } /** * Adds a filetype "dot" extension to filter against. * * For example: the following code will create a filter that filters * out all files except those that end in ".jpg" and ".tif": * * ExampleFileFilter filter = new ExampleFileFilter(); * filter.addExtension("jpg"); * filter.addExtension("tif"); * * Note that the "." before the extension is not needed and will be ignored. */ public void addExtension(String extension) { if(filters == null) { filters = new Hashtable(5); } filters.put(extension.toLowerCase(), this); fullDescription = null; } /** * Returns the human readable description of this filter. For * example: "JPEG and GIF Image Files (*.jpg, *.gif)" * * @see setDescription * @see setExtensionListInDescription * @see isExtensionListInDescription * @see FileFilter#getDescription */ public String getDescription() { if(fullDescription == null) { if(description == null || isExtensionListInDescription()) { fullDescription = description==null ? "(" : description + " ("; // build the description from the extension list Enumeration extensions = filters.keys(); if(extensions != null) { fullDescription += "." + (String) extensions.nextElement(); while (extensions.hasMoreElements()) { fullDescription += ", " + (String) extensions.nextElement(); } } fullDescription += ")"; } else { fullDescription = description; } } return fullDescription; } /** * Sets the human readable description of this filter. For * example: filter.setDescription("Gif and JPG Images"); * * @see setDescription * @see setExtensionListInDescription * @see isExtensionListInDescription */ public void setDescription(String description) { this.description = description; fullDescription = null; } /** * Determines whether the extension list (.jpg, .gif, etc) should * show up in the human readable description. * * Only relevent if a description was provided in the constructor * or using setDescription(); * * @see getDescription * @see setDescription * @see isExtensionListInDescription */ public void setExtensionListInDescription(boolean b) { useExtensionsInDescription = b; fullDescription = null; } /** * Returns whether the extension list (.jpg, .gif, etc) should * show up in the human readable description. * * Only relevent if a description was provided in the constructor * or using setDescription(); * * @see getDescription * @see setDescription * @see setExtensionListInDescription */ public boolean isExtensionListInDescription() { return useExtensionsInDescription; } }
import java.util.Hashtable;
import java.util.Enumeration;
import javax.swing.*;
import javax.swing.filechooser.*;public class MyFileFilter extends FileFilter { private static String TYPE_UNKNOWN = "Type Unknown";
private static String HIDDEN_FILE = "Hidden File"; private Hashtable filters = null;
private String description = null;
private String fullDescription = null;
private boolean useExtensionsInDescription = true; /**
* Creates a file filter. If no filters are added, then all
* files are accepted.
*
* @see #addExtension
*/
public MyFileFilter() {
this.filters = new Hashtable();
} /**
* Creates a file filter that accepts files with the given extension.
* Example: new ExampleFileFilter("jpg");
*
* @see #addExtension
*/
public MyFileFilter(String extension) {
this(extension,null);
} /**
* Creates a file filter that accepts the given file type.
* Example: new ExampleFileFilter("jpg", "JPEG Image Images");
*
* Note that the "." before the extension is not needed. If
* provided, it will be ignored.
*
* @see #addExtension
*/
public MyFileFilter(String extension, String description) {
this();
if(extension!=null) addExtension(extension);
if(description!=null) setDescription(description);
} /**
* Creates a file filter from the given string array.
* Example: new ExampleFileFilter(String {"gif", "jpg"});
*
* Note that the "." before the extension is not needed adn
* will be ignored.
*
* @see #addExtension
*/
public MyFileFilter(String[] filters) {
this(filters, null);
} /**
* Creates a file filter from the given string array and description.
* Example: new ExampleFileFilter(String {"gif", "jpg"}, "Gif and JPG Images");
*
* Note that the "." before the extension is not needed and will be ignored.
*
* @see #addExtension
*/
public MyFileFilter(String[] filters, String description) {
this();
for (int i = 0; i < filters.length; i++) {
// add filters one by one
addExtension(filters[i]);
}
if(description!=null) setDescription(description);
} /**
* Return true if this file should be shown in the directory pane,
* false if it shouldn't.
*
* Files that begin with "." are ignored.
*
* @see #getExtension
* @see FileFilter#accepts
*/
public boolean accept(File f) {
if(f != null) {
if(f.isDirectory()) {
return true;
}
String extension = getExtension(f);
if(extension != null && filters.get(getExtension(f)) != null) {
return true;
}
}
return false;
} /**
* Return the extension portion of the file's name .
*
* @see #getExtension
* @see FileFilter#accept
*/
public String getExtension(File f) {
if(f != null) {
String filename = f.getName();
int i = filename.lastIndexOf('.');
if(i>0 && i<filename.length()-1) {
return filename.substring(i+1).toLowerCase();
};
}
return null;
} /**
* Adds a filetype "dot" extension to filter against.
*
* For example: the following code will create a filter that filters
* out all files except those that end in ".jpg" and ".tif":
*
* ExampleFileFilter filter = new ExampleFileFilter();
* filter.addExtension("jpg");
* filter.addExtension("tif");
*
* Note that the "." before the extension is not needed and will be ignored.
*/
public void addExtension(String extension) {
if(filters == null) {
filters = new Hashtable(5);
}
filters.put(extension.toLowerCase(), this);
fullDescription = null;
}
/**
* Returns the human readable description of this filter. For
* example: "JPEG and GIF Image Files (*.jpg, *.gif)"
*
* @see setDescription
* @see setExtensionListInDescription
* @see isExtensionListInDescription
* @see FileFilter#getDescription
*/
public String getDescription() {
if(fullDescription == null) {
if(description == null || isExtensionListInDescription()) {
fullDescription = description==null ? "(" : description + " (";
// build the description from the extension list
Enumeration extensions = filters.keys();
if(extensions != null) {
fullDescription += "." + (String) extensions.nextElement();
while (extensions.hasMoreElements()) {
fullDescription += ", " + (String) extensions.nextElement();
}
}
fullDescription += ")";
} else {
fullDescription = description;
}
}
return fullDescription;
} /**
* Sets the human readable description of this filter. For
* example: filter.setDescription("Gif and JPG Images");
*
* @see setDescription
* @see setExtensionListInDescription
* @see isExtensionListInDescription
*/
public void setDescription(String description) {
this.description = description;
fullDescription = null;
} /**
* Determines whether the extension list (.jpg, .gif, etc) should
* show up in the human readable description.
*
* Only relevent if a description was provided in the constructor
* or using setDescription();
*
* @see getDescription
* @see setDescription
* @see isExtensionListInDescription
*/
public void setExtensionListInDescription(boolean b) {
useExtensionsInDescription = b;
fullDescription = null;
} /**
* Returns whether the extension list (.jpg, .gif, etc) should
* show up in the human readable description.
*
* Only relevent if a description was provided in the constructor
* or using setDescription();
*
* @see getDescription
* @see setDescription
* @see setExtensionListInDescription
*/
public boolean isExtensionListInDescription() {
return useExtensionsInDescription;
}
}