Only accept a file type in JFileChooser ?

[Steven Zeng]

Hi all,
Would you please tell me how to let a JFileChooser only accept one file type for example "*.jar"(I know FileFilter). In fact, I don't want that user can select "all files" in JFileChooser, but I don't know how to disable the JCombobox.
Thanks ahead!

[aminur rashid]

make ur own class extenidng
javax.swing.filechooser.FileFilter

like

import java.io.File;
import java.util.Hashtable;
import java.util.Enumeration;
import javax.swing.*;
import javax.swing.filechooser.*;
/**
 * A convenience implementation of FileFilter that filters out
 * all files except for those type extensions that it knows about.
 *
 * Extensions are of the type ".foo", which is typically found on
 * Windows and Unix boxes, but not on Macinthosh. Case is ignored.
 *
 * Example - create a new filter that filerts out all files
 * but gif and jpg image files:
 *
 *     JFileChooser chooser = new JFileChooser();
 *     ExampleFileFilter filter = new ExampleFileFilter(
 *                   new String{"gif", "jpg"}, "JPEG & GIF Images")
 *     chooser.addChoosableFileFilter(filter);
 *     chooser.showOpenDialog(this);
 *
 */
public class ExtensionFileFilter 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 ExtensionFileFilter() {
this.filters = new Hashtable();
    }
    /**
     * Creates a file filter that accepts files with the given extension.
     * Example: new ExampleFileFilter("jpg");
     *
     * @see #addExtension
     */
    public ExtensionFileFilter(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 ExtensionFileFilter(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 ExtensionFileFilter(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 ExtensionFileFilter(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;
    }

now add this filter to ur filechooser

ExtensionFileFilter jarFilter = new ExtensionFileFilter( 
                   new String("jar"), "Jar Files");
  fileChooser.addChoosableFileFilter( jarFilter);

Hope this will help....

[Steven Zeng]

In fact i want that in JFileChooser user can not select "all files *.*" in file type ComBoBox. However thanks for your reply

[Manish Hatwalne]

Originally posted by Steven Zeng:
In fact i want that in JFileChooser user can not select "all files *.*" in file type ComBoBox. However thanks for your reply

Use -
fileChooser.setAcceptAllFileFilterUsed(false);
HTH,
- Manish