Doc that can
* be used in many common printing requests.
* It can handle all of the presently defined "pre-defined" doc flavors
* defined as static variables in the DocFlavor class.
* * In particular this class implements certain required semantics of the * Doc specification as follows: *
* If the print data is a stream, or a print job requests data as a
* stream, then SimpleDoc does not monitor if the service
* properly closes the stream after data transfer completion or job
* termination.
* Clients may prefer to use provide their own implementation of doc that
* adds a listener to monitor job completion and to validate that
* resources such as streams are freed (ie closed).
*/
public final class SimpleDoc implements Doc {
private DocFlavor flavor;
private DocAttributeSet attributes;
private Object printData;
private Reader reader;
private InputStream inStream;
/**
* Constructs a SimpleDoc with the specified
* print data, doc flavor and doc attribute set.
* @param printData the print data object
* @param flavor the DocFlavor object
* @param attributes a DocAttributeSet, which can
* be null
* @throws IllegalArgumentException if flavor or
* printData is null, or the
* printData does not correspond
* to the specified doc flavor--for example, the data is
* not of the type specified as the representation in the
* DocFlavor.
*/
public SimpleDoc(Object printData,
DocFlavor flavor, DocAttributeSet attributes) {
if (flavor == null || printData == null) {
throw new IllegalArgumentException("null argument(s)");
}
Class repClass = null;
try {
String className = flavor.getRepresentationClassName();
sun.reflect.misc.ReflectUtil.checkPackageAccess(className);
repClass = Class.forName(className, false,
Thread.currentThread().getContextClassLoader());
} catch (Throwable e) {
throw new IllegalArgumentException("unknown representation class");
}
if (!repClass.isInstance(printData)) {
throw new IllegalArgumentException("data is not of declared type");
}
this.flavor = flavor;
if (attributes != null) {
this.attributes = AttributeSetUtilities.unmodifiableView(attributes);
}
this.printData = printData;
}
/**
* Determines the doc flavor in which this doc object will supply its
* piece of print data.
*
* @return Doc flavor.
*/
public DocFlavor getDocFlavor() {
return flavor;
}
/**
* Obtains the set of printing attributes for this doc object. If the
* returned attribute set includes an instance of a particular attribute
* X, the printer must use that attribute value for this doc,
* overriding any value of attribute X in the job's attribute set.
* If the returned attribute set does not include an instance
* of a particular attribute X or if null is returned, the printer
* must consult the job's attribute set to obtain the value for
* attribute X, and if not found there, the printer must use an
* implementation-dependent default value. The returned attribute set is
* unmodifiable.
*
* @return Unmodifiable set of printing attributes for this doc, or null
* to obtain all attribute values from the job's attribute
* set.
*/
public DocAttributeSet getAttributes() {
return attributes;
}
/*
* Obtains the print data representation object that contains this doc
* object's piece of print data in the format corresponding to the
* supported doc flavor.
* The getPrintData() method returns an instance of
* the representation class whose name is given by
* {@link DocFlavor#getRepresentationClassName() getRepresentationClassName},
* and the return value can be cast
* from class Object to that representation class.
*
* @return Print data representation object.
*
* @exception IOException if the representation class is a stream and
* there was an I/O error while constructing the stream.
*/
public Object getPrintData() throws IOException {
return printData;
}
/**
* Obtains a reader for extracting character print data from this doc.
* The Doc implementation is required to support this
* method if the DocFlavor has one of the following print
* data representation classes, and return null
* otherwise:
*
char[]
* java.lang.String
* java.io.Reader
* Reader for reading the print data as a stream
* of characters from the print data representation object.
* However, if the print data representation object is itself a
* Reader then the print data representation object is
* simply returned.
*
* @return a Reader for reading the print data
* characters from this doc.
* If a reader cannot be provided because this doc does not meet
* the criteria stated above, null is returned.
*
* @exception IOException if there was an I/O error while creating
* the reader.
*/
public Reader getReaderForText() throws IOException {
if (printData instanceof Reader) {
return (Reader)printData;
}
synchronized (this) {
if (reader != null) {
return reader;
}
if (printData instanceof char[]) {
reader = new CharArrayReader((char[])printData);
}
else if (printData instanceof String) {
reader = new StringReader((String)printData);
}
}
return reader;
}
/**
* Obtains an input stream for extracting byte print data from
* this doc.
* The Doc implementation is required to support this
* method if the DocFlavor has one of the following print
* data representation classes; otherwise this method
* returns null:
*
byte[]
* java.io.InputStream
*
* @return an InputStream for reading the print data
* bytes from this doc. If an input stream cannot be
* provided because this doc does not meet
* the criteria stated above, null is returned.
*
* @exception IOException
* if there was an I/O error while creating the input stream.
*/
public InputStream getStreamForBytes() throws IOException {
if (printData instanceof InputStream) {
return (InputStream)printData;
}
synchronized (this) {
if (inStream != null) {
return inStream;
}
if (printData instanceof byte[]) {
inStream = new ByteArrayInputStream((byte[])printData);
}
}
return inStream;
}
}