com.sun.squawk.util
Class StructuredFileInputStream

java.lang.Object
  com.sun.squawk.util.StructuredFileInputStream

public abstract class StructuredFileInputStream
extends Object

An instance of StructuredInputStream is used to read a file that must conform to some given format such as a class file or a suite file.

Author:

Doug Simon

Constructor Summary

StructuredFileInputStream(InputStream in, String filePath, String traceFeature)
Creates a StructuredFileInputStream that reads class components from a given input stream.

Method Summary

void	close() Closes this reader and releases any system resources associated with the underlying input stream.
abstract Error	formatError(String msg) Throw a LinkageError to indicate there was an IO error or the file did not conform to the structure expected by the client of this class.
int	getBytesRead() Gets the number of bytes that have been read so far.
String	getFileName() Gets the name of the file from which this reader is reading.
int	readByte(String prefix) Reads a signed byte from the file.
double	readDouble(String prefix) Reads a double value from the file.
void	readEOF() Ensures that the input stream is at the end of the file.
float	readFloat(String prefix) Reads a float value from the file.
void	readFully(byte[] b, String prefix) Reads some bytes from the class file and stores them into the buffer array b.
int	readInt(String prefix) Reads an integer from the class file.
long	readLong(String prefix) Reads a long value from the file.
int	readShort(String prefix) Reads a signed short from the file.
int	readUnsignedByte(String prefix) Reads an unsigned byte from the file.
int	readUnsignedShort(String prefix) Reads an unsigned short from the class file.
String	readUTF(String prefix) Reads a UTF-8 encoded string from the file.
void	skip(int n, String prefix) Skips over and discards n bytes of data from the file.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StructuredFileInputStream

public StructuredFileInputStream(InputStream in,
                                 String filePath,
                                 String traceFeature)

Creates a StructuredFileInputStream that reads class components from a given input stream.

Parameters:

in - the input stream

filePath - the file from which in was created

traceFeature - the tracing feature that must be enabled if tracing is to be enabled

Method Detail

getFileName

public final String getFileName()

Gets the name of the file from which this reader is reading.

Returns:

the name of the file from which this reader is reading

formatError

public abstract Error formatError(String msg)

Throw a LinkageError to indicate there was an IO error or the file did not conform to the structure expected by the client of this class.

Parameters:

msg - the cause of the error

Returns:

the LinkageError raised

getBytesRead

public int getBytesRead()

Gets the number of bytes that have been read so far. This only accounts for whole units that have been successfully read. For example, if a call to readInt(java.lang.String) failed with an IOException, any bytes read during the call will not be included in the total.

Returns:

int

readFully

public final void readFully(byte[] b,
                            String prefix)

Reads some bytes from the class file and stores them into the buffer array b. The number of bytes read is equal to the length of b.

Parameters:

b - the buffer to fill

prefix - the optional prefix used when tracing this read

readInt

public final int readInt(String prefix)

Reads an integer from the class file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readInt()

readUnsignedShort

public final int readUnsignedShort(String prefix)

Reads an unsigned short from the class file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readUnsignedShort()

readUnsignedByte

public final int readUnsignedByte(String prefix)

Reads an unsigned byte from the file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readUnsignedByte()

readShort

public final int readShort(String prefix)

Reads a signed short from the file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readShort()

readByte

public final int readByte(String prefix)

Reads a signed byte from the file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readByte()

readLong

public final long readLong(String prefix)

Reads a long value from the file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readLong()

readFloat

public final float readFloat(String prefix)

Reads a float value from the file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readFloat()

readDouble

public final double readDouble(String prefix)

Reads a double value from the file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readDouble()

readUTF

public final String readUTF(String prefix)

Reads a UTF-8 encoded string from the file.

Parameters:

prefix - the optional prefix used when tracing this read

Returns:

the value read

See Also:

DataInputStream.readUTF()

skip

public final void skip(int n,
                       String prefix)

Skips over and discards n bytes of data from the file.

Parameters:

n - the number of bytes to be skipped.

prefix - the optional prefix used when tracing this read

readEOF

public void readEOF()

Ensures that the input stream is at the end of the file.

Throws:

a - LinkageError if the input stream is not at the end of the file

close

public final void close()

Closes this reader and releases any system resources associated with the underlying input stream.