FileDocCategorySizeDatePackage
BasicPullSourceStream.javaAPI DocJMF 2.1.1e8503Mon May 12 12:20:54 BST 2003com.sun.media.protocol

BasicPullSourceStream

public class BasicPullSourceStream extends Object implements Seekable, PullSourceStream

Fields Summary
protected InputStream
stream
the stream which PullSourceStream's inheriting classes handles
protected long
location
the current location in the stream
protected boolean
eofReached
a flag to indicate EOF reached
protected long
contentLength
protected URL
url
protected URLConnection
urlC
private boolean
needConnectPermission
private static JMFSecurity
jmfSecurity
private static boolean
securityPrivelege
private Method[]
m
private Class[]
cl
private Object[]
args
Constructors Summary
public BasicPullSourceStream(URL url, InputStream stream, long contentLength, boolean needConnectPermission)


     
	try {
	    jmfSecurity = JMFSecurityManager.getJMFSecurity();
	    securityPrivelege = true;
	} catch (SecurityException e) {
	}
    

	this.needConnectPermission = needConnectPermission;
	// System.out.println("bpss: needConnectPermission is " + needConnectPermission);
        if (stream != null) {
	    this.stream = stream; // stream is opened
	    this.contentLength = contentLength;
        } else {
	    // Check with Doron if we can remove the else block.
	    // TODO: if not, add security stuff.
	    try {
		urlC = url.openConnection();
		this.contentLength = urlC.getContentLength();
		this.stream = urlC.getInputStream();
		if (this.stream == null)
		    throw new IOException("Got null input stream from url connection");
	    } catch (IOException ie) {
   	        throw new IOException("error in connection");
	    }
        }

        location = 0;
   	eofReached = false;
        this.url = url;
Methods Summary
public voidclose()
close the stream which PullSourceStream handles

exception
if an I/O error occurs

	try {
	    stream.close();
	    stream = null;
        } catch (Exception e) {
	    System.out.println("BasicPullSourceStream close - IOException");
        }
public booleanendOfStream()
Find out if the end of the stream has been reached.

returns
true if there is no more data.

        return eofReached;
public javax.media.protocol.ContentDescriptorgetContentDescriptor()
Get the current content type for this stream.

returns
The current ContentDescriptor for this stream.

        return null;
public longgetContentLength()

	return contentLength;
public java.lang.ObjectgetControl(java.lang.String controlType)
Obtain the object that implements the specified Class or Interface The full class or interface name must be used. If the control is not supported then null is returned.

returns
the object that implements the control, or null.

        return null;
public java.lang.Object[]getControls()
Obtain the collection of objects that control the object that implements this interface. If no controls are supported, a zero length array is returned.

returns
the collection of object controls

        Object[] objects = new Object[0];

        return objects;
public booleanisRandomAccess()
Find out if this source can position anywhere in the stream. If the stream is not random access, it can only be repositioned to the beginning.

returns
returns true if the stream is random access, false if the stream can only be reset to the beginning.

        return true;
public intread(byte[] buffer, int offset, int length)
read will perform a blocking read from stream. If buffer is null up to length bytes are read and discarded.

param
buffer buffer to read into
param
offset offset in the buffer to put data
param
length bytes to read
returns
bytes read or -1 for end of media
exception
IOException

        int bytesRead;
        int len = length;
        int off = offset;
        do {
	    bytesRead = stream.read(buffer, off, len);
            if (bytesRead == -1) {
		eofReached = true;
		int totalBytesRead = length - len;
		return (totalBytesRead > 0) ? totalBytesRead : -1;
            } else {
    	    	location += bytesRead;
                len -= bytesRead;
                off += bytesRead;
            }
        } while (len != 0);

        return length;
voidreopenStream()

	// reopen the stream and go to new location
	// System.out.println("$$$ bpss: seek back");
	try {
	    if (stream!=null) {
		stream.close();
	    }
	    // System.out.println("bpss: seek: needConnectPermission " +
	    //	   needConnectPermission);
	    if (needConnectPermission) {
		if ( /*securityPrivelege && */ (jmfSecurity != null) ) {
		    try {
			if (jmfSecurity.getName().startsWith("jmf-security")) {
			    jmfSecurity.requestPermission(m, cl, args, JMFSecurity.CONNECT);
			    m[0].invoke(cl[0], args[0]);
			} else if (jmfSecurity.getName().startsWith("internet")) {
			    PolicyEngine.checkPermission(PermissionID.NETIO);
			    PolicyEngine.assertPermission(PermissionID.NETIO);
			}
		    } catch (Throwable e) {
			if (JMFSecurityManager.DEBUG) {
			    System.err.println("Unable to get connect " +
					       " privilege  " + e);
			}
			securityPrivelege = false;
			throw new IOException(JMFI18N.getResource("error.connectionerror") +
					      e.getMessage());
		    }
		}
	    }
	    
	    urlC = url.openConnection(); // This will not throw Security Exceptions
	    
	    try {
		if ( (jmfSecurity != null) && (jmfSecurity.getName().startsWith("jdk12"))) {
		    Constructor cons = jdk12ConnectionAction.cons;
		    stream = (InputStream) jdk12.doPrivM.invoke(
								jdk12.ac,
								new Object[] {
			cons.newInstance( new Object[] {urlC} )
			    }
								);
		    
		} else {
		    // stream=url.openStream();
		    stream = urlC.getInputStream();
		}
	    } catch (Exception e) {
		System.err.println("Unable to re-open a URL connection " + e);
		throw new IOException(JMFI18N.getResource("error.connectionerror") +
				      e.getMessage());
	    }
	} catch (IOException ex) {
	}
public longseek(long where)
Seek to the specified point in the stream.

param
where the position to seek to
returns
the new stream position

        long oldLocation = location;
	location = where;
       	try {
	    if (where < oldLocation) {
		reopenStream();
    	       	eofReached = false;
		return skip(stream, where);
            } else  {
		return skip(stream, (where - oldLocation));
	    }
        } catch (IOException e) {
// 	    System.err.println("Exception in PullSourceStream::seek(long) " +
// 			       e.toString());
            //System.exit(0);
            return 0; // dummy
        }
private longskip(java.io.InputStream istream, long amount)

	long remaining = amount;
	while (remaining > 0) {
	    long actual = istream.skip(remaining);
	    remaining -= actual;
	}
	return amount;
public longtell()
Obtain the current point in the stream.

returns
the current point in the stream

        return location;
public booleanwillReadBlock()
willReadBlock indicates whether there data available now.

returns
true if read would block, false if not.

        try {
            return (stream.available() == 0);
        } catch (IOException e) {
            System.err.println("Exception PullSourceStream::willReadBlock " +
			       e.toString());
            return true;
        }