/**
* This method has the same behavior as {@link #equals(Object)}. The only difference being that it
* takes a {@code DataFlavor} instance as a parameter.
*
* @param that the <code>DataFlavor</code> to compare with <code>this</code>
* @return <code>true</code> if <code>that</code> is equivalent to this <code>DataFlavor</code>;
* <code>false</code> otherwise
* @see #selectBestTextFlavor
*/
public boolean equals(DataFlavor that) {
if (that == null) {
return false;
}
if (this == that) {
return true;
}
if (representationClass == null) {
if (that.getRepresentationClass() != null) {
return false;
}
} else {
if (!representationClass.equals(that.getRepresentationClass())) {
return false;
}
}
if (mimeType == null) {
if (that.mimeType != null) {
return false;
}
} else {
if (!mimeType.match(that.mimeType)) {
return false;
}
if ("text".equals(getPrimaryType())
&& DataTransferer.doesSubtypeSupportCharset(this)
&& representationClass != null
&& !(isRepresentationClassReader()
|| String.class.equals(representationClass)
|| isRepresentationClassCharBuffer()
|| DataTransferer.charArrayClass.equals(representationClass))) {
String thisCharset = DataTransferer.canonicalName(getParameter("charset"));
String thatCharset = DataTransferer.canonicalName(that.getParameter("charset"));
if (thisCharset == null) {
if (thatCharset != null) {
return false;
}
} else {
if (!thisCharset.equals(thatCharset)) {
return false;
}
}
}
}
return true;
}
/**
* Compares two <code>DataFlavor</code> objects. Returns a negative integer, zero, or a positive
* integer as the first <code>DataFlavor</code> is worse than, equal to, or better than the
* second.
*
* <p><code>DataFlavor</code>s are ordered according to the rules outlined for <code>
* selectBestTextFlavor</code>.
*
* @param obj1 the first <code>DataFlavor</code> to be compared
* @param obj2 the second <code>DataFlavor</code> to be compared
* @return a negative integer, zero, or a positive integer as the first argument is worse, equal
* to, or better than the second
* @throws ClassCastException if either of the arguments is not an instance of <code>DataFlavor
* </code>
* @throws NullPointerException if either of the arguments is <code>null</code>
* @see #selectBestTextFlavor
*/
public int compare(Object obj1, Object obj2) {
DataFlavor flavor1 = (DataFlavor) obj1;
DataFlavor flavor2 = (DataFlavor) obj2;
if (flavor1.isFlavorTextType()) {
if (flavor2.isFlavorTextType()) {
return super.compare(obj1, obj2);
} else {
return 1;
}
} else if (flavor2.isFlavorTextType()) {
return -1;
} else {
return 0;
}
}
/**
* Common initialization code called from various constructors.
*
* @param mimeType the MIME Content Type (must have a class= param)
* @param humanPresentableName the human Presentable Name or <code>null</code>
* @param classLoader the fallback class loader to resolve against
* @throws MimeTypeParseException
* @throws ClassNotFoundException
* @throws NullPointerException if <code>mimeType</code> is null
* @see tryToLoadClass
*/
private void initialize(String mimeType, String humanPresentableName, ClassLoader classLoader)
throws MimeTypeParseException, ClassNotFoundException {
if (mimeType == null) {
throw new NullPointerException("mimeType");
}
this.mimeType = new MimeType(mimeType); // throws
String rcn = getParameter("class");
if (rcn == null) {
if ("application/x-java-serialized-object".equals(this.mimeType.getBaseType()))
throw new IllegalArgumentException("no representation class specified for:" + mimeType);
else representationClass = java.io.InputStream.class; // default
} else { // got a class name
representationClass = DataFlavor.tryToLoadClass(rcn, classLoader);
}
this.mimeType.setParameter("class", representationClass.getName());
if (humanPresentableName == null) {
humanPresentableName = this.mimeType.getParameter("humanPresentableName");
if (humanPresentableName == null)
humanPresentableName = this.mimeType.getPrimaryType() + "/" + this.mimeType.getSubType();
}
this.humanPresentableName = humanPresentableName; // set it.
this.mimeType.removeParameter("humanPresentableName"); // just in case
}
/** Restores this <code>DataFlavor</code> from a Serialized state. */
public synchronized void readExternal(ObjectInput is) throws IOException, ClassNotFoundException {
String rcn = null;
mimeType = (MimeType) is.readObject();
if (mimeType != null) {
humanPresentableName = mimeType.getParameter("humanPresentableName");
mimeType.removeParameter("humanPresentableName");
rcn = mimeType.getParameter("class");
if (rcn == null) {
throw new IOException("no class parameter specified in: " + mimeType);
}
}
try {
representationClass = (Class) is.readObject();
} catch (OptionalDataException ode) {
if (!ode.eof || ode.length != 0) {
throw ode;
}
// Ensure backward compatibility.
// Old versions didn't write the representation class to the stream.
if (rcn != null) {
representationClass = DataFlavor.tryToLoadClass(rcn, getClass().getClassLoader());
}
}
}
/**
* Selects the best text <code>DataFlavor</code> from an array of <code>
* DataFlavor</code>s. Only <code>DataFlavor.stringFlavor</code>, and equivalent flavors, and
* flavors that have a primary MIME type of "text", are considered for selection.
*
* <p>Flavors are first sorted by their MIME types in the following order:
*
* <ul>
* <li>"text/sgml"
* <li>"text/xml"
* <li>"text/html"
* <li>"text/rtf"
* <li>"text/enriched"
* <li>"text/richtext"
* <li>"text/uri-list"
* <li>"text/tab-separated-values"
* <li>"text/t140"
* <li>"text/rfc822-headers"
* <li>"text/parityfec"
* <li>"text/directory"
* <li>"text/css"
* <li>"text/calendar"
* <li>"application/x-java-serialized-object"
* <li>"text/plain"
* <li>"text/<other>"
* </ul>
*
* <p>For example, "text/sgml" will be selected over "text/html", and <code>
* DataFlavor.stringFlavor</code> will be chosen over <code>DataFlavor.plainTextFlavor</code>.
*
* <p>If two or more flavors share the best MIME type in the array, then that MIME type will be
* checked to see if it supports the charset parameter.
*
* <p>The following MIME types support, or are treated as though they support, the charset
* parameter:
*
* <ul>
* <li>"text/sgml"
* <li>"text/xml"
* <li>"text/html"
* <li>"text/enriched"
* <li>"text/richtext"
* <li>"text/uri-list"
* <li>"text/directory"
* <li>"text/css"
* <li>"text/calendar"
* <li>"application/x-java-serialized-object"
* <li>"text/plain"
* </ul>
*
* The following MIME types do not support, or are treated as though they do not support, the
* charset parameter:
*
* <ul>
* <li>"text/rtf"
* <li>"text/tab-separated-values"
* <li>"text/t140"
* <li>"text/rfc822-headers"
* <li>"text/parityfec"
* </ul>
*
* For "text/<other>" MIME types, the first time the JRE needs to determine whether the MIME
* type supports the charset parameter, it will check whether the parameter is explicitly listed
* in an arbitrarily chosen <code>DataFlavor</code> which uses that MIME type. If so, the JRE will
* assume from that point on that the MIME type supports the charset parameter and will not check
* again. If the parameter is not explicitly listed, the JRE will assume from that point on that
* the MIME type does not support the charset parameter and will not check again. Because this
* check is performed on an arbitrarily chosen <code>DataFlavor</code>, developers must ensure
* that all <code>DataFlavor</code>s with a "text/<other>" MIME type specify the charset
* parameter if it is supported by that MIME type. Developers should never rely on the JRE to
* substitute the platform's default charset for a "text/<other>" DataFlavor. Failure to
* adhere to this restriction will lead to undefined behavior.
*
* <p>If the best MIME type in the array does not support the charset parameter, the flavors which
* share that MIME type will then be sorted by their representation classes in the following
* order: <code>java.io.InputStream</code>, <code>java.nio.ByteBuffer</code>, <code>[B</code>,
* <all others>.
*
* <p>If two or more flavors share the best representation class, or if no flavor has one of the
* three specified representations, then one of those flavors will be chosen
* non-deterministically.
*
* <p>If the best MIME type in the array does support the charset parameter, the flavors which
* share that MIME type will then be sorted by their representation classes in the following
* order: <code>java.io.Reader</code>, <code>java.lang.String</code>, <code>java.nio.CharBuffer
* </code>, <code>[C</code>, <all others>.
*
* <p>If two or more flavors share the best representation class, and that representation is one
* of the four explicitly listed, then one of those flavors will be chosen non-deterministically.
* If, however, no flavor has one of the four specified representations, the flavors will then be
* sorted by their charsets. Unicode charsets, such as "UTF-16", "UTF-8", "UTF-16BE", "UTF-16LE",
* and their aliases, are considered best. After them, the platform default charset and its
* aliases are selected. "US-ASCII" and its aliases are worst. All other charsets are chosen in
* alphabetical order, but only charsets supported by this implementation of the Java platform
* will be considered.
*
* <p>If two or more flavors share the best charset, the flavors will then again be sorted by
* their representation classes in the following order: <code>java.io.InputStream</code>, <code>
* java.nio.ByteBuffer</code>, <code>[B</code>, <all others>.
*
* <p>If two or more flavors share the best representation class, or if no flavor has one of the
* three specified representations, then one of those flavors will be chosen
* non-deterministically.
*
* @param availableFlavors an array of available <code>DataFlavor</code>s
* @return the best (highest fidelity) flavor according to the rules specified above, or <code>
* null</code>, if <code>availableFlavors</code> is <code>null</code>, has zero length, or
* contains no text flavors
* @since 1.3
*/
public static final DataFlavor selectBestTextFlavor(DataFlavor[] availableFlavors) {
if (availableFlavors == null || availableFlavors.length == 0) {
return null;
}
if (textFlavorComparator == null) {
textFlavorComparator = new TextFlavorComparator();
}
DataFlavor bestFlavor =
(DataFlavor) Collections.max(Arrays.asList(availableFlavors), textFlavorComparator);
if (!bestFlavor.isFlavorTextType()) {
return null;
}
return bestFlavor;
}
