/trunk/org.mwc.cmap.legacy/src/MWC/GUI/S57/support/BinaryFile.java

// **********************************************************************
// 
// <copyright>
// 
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  (617) 873-8000
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// 
// </copyright>
// **********************************************************************
// 
// $Source: i:/mwc/coag/asset/cvsroot/util/MWC/GUI/S57/support/BinaryFile.java,v $
// $RCSfile: BinaryFile.java,v $
// $Revision: 1.1 $
// $Date: 2007/04/27 09:20:00 $
// $Author: ian.mayo $
// 
// **********************************************************************

package MWC.GUI.S57.support;

import java.io.EOFException;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.WeakReference;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.Vector;

import com.bbn.openmap.Environment;
import com.bbn.openmap.MoreMath;
import com.bbn.openmap.util.Debug;

/**
 * The BinaryFile is the standard object used to access data files. It
 * acts like a RandomAccessFile, but will work on jar file contents
 * and URLs, too. The source of the data is isolated through the
 * InputReader interface.
 */
public class BinaryFile {

    private InputReader inputReader = null;

    /**
     * The byte order of the underlying file. (<code>true</code>==
     * MSB-First == big-endian)
     */
    protected boolean MSBFirst = false;

    /**
     * Constructs a new BinaryFile with the specified file as the
     * input. The default byte-order is LSB first. Reads start at the
     * first byte of the file.
     * 
     * @param f the file to be opened for reading
     * @exception IOException pass-through errors from opening a
     *            RandomAccessFile with f
     * @see java.io.RandomAccessFile
     */
    public BinaryFile(final File f) throws IOException {
        inputReader = new FileInputReader(f);
    }

    /**
     * Constructs a new BinaryFile with the specified file as the
     * input. The byte-order is undefined. Reads start at the first
     * byte of the file. This constructor looks for the file with the
     * string given, and will call the correct constructor as
     * appropriate. If the string represents a file available locally,
     * then the BinaryFile will be accessed with a FileInputReader
     * using a RandomAccessFile. If it's only available as a resource,
     * then a StreamInputReader will be used. The name should be a
     * path to a file, or the name of a resource that can be found in
     * the classpath, or a URL.
     * 
     * @param name the name of the file to be opened for reading
     * @exception IOException pass-through errors from opening the
     *            file.
     */
    public BinaryFile(final String name) throws IOException {
        boolean showDebug = false;
        if (Debug.debugging("binaryfile")) {
            showDebug = true;
        }

        if (showDebug) {
            Debug.output("BinaryFile: trying to figure out how to handle "
                    + name);
        }

        try {
            File file = null;
            URL url = null;

            if (!Environment.isApplet()) {
                file = new File(name);
            }

            if (file != null && file.exists()) {
                // If the string represents a file, then we want to
                // use the RandomAccessFile aspect of the BinaryFile.
                setInputReader(new FileInputReader(file));
            } else {
                // url = ClassLoader.getSystemResource(name);
                url = Thread.currentThread()
                        .getContextClassLoader()
                        .getResource(name);

                // OK, now we want to look around for the file, in the
                // classpaths, and as a resource. It may be a file in
                // a classpath, available for direct access.
                if (url != null) {

                    final String newname = url.getFile();
                    if (showDebug) {
                        Debug.output("BinaryFile: looking for " + newname);
                    }

                    if (!Environment.isApplet()) {
                        file = new File(newname);
                    }

                    if (file != null && file.exists()) {
                        // It's still a file, available directly.
                        // Access it with the RandomAccessFile
                        setInputReader(new FileInputReader(file));
                    } else {
                        // Need to get it as a resource. Needs
                        // special handling if it's coming in a jar
                        // file. Jar file references have a "!" in
                        // them
                        if (!setJarInputReader(newname)) {
                            if (showDebug) {
                                Debug.output(" trying as url: " + url);
                            }
                            setInputReader(new URLInputReader(url));
                        }

                    }

                } else if (Environment.isApplet()) {
                    if (showDebug) {
                        Debug.output(" As applet, checking codebase...");
                    }
                    // Look in the codebase for applets...
                    final URL[] cba = new URL[1];
                    cba[0] = Environment.getApplet().getCodeBase();

                    final URLClassLoader ucl = URLClassLoader.newInstance(cba);
                    url = ucl.getResource(name);

                    if (url != null) {
                        setInputReader(new URLInputReader(url));
                    }
                }

                // It's not in the classpath, so try it as a URL.
                if (inputReader == null) {

                    if (showDebug) {
                        Debug.output(" lastly, trying as URL: " + name);
                    }
                    try {
                        setInputReader(new URLInputReader(new URL(name)));
                    } catch (final java.security.AccessControlException ace) {
                        Debug.output("BinaryFile: " + name
                                + " couldn't be accessed.");
                        throw new IOException("AccessControlException trying to fetch "
                                + name + " as a URL");
                    }
                }

            }

            if (inputReader == null) {
                throw new FileNotFoundException("BinaryFile can't find: "
                        + name);
            }

        } catch (final IOException ioe) {
            throw ioe;
        }
    }

    /**
     * Takes a name of a file, and checks to see if it reflects an
     * entry in a jar file. (Check the filename and see if it looks
     * like "jarfile!jarfileentry".) If it is, it separates the path,
     * and set the inputReader to a JarInputReader and returns true.
     * If not, it returns false.
     */
    protected boolean setJarInputReader(final String name) throws IOException {

        try {
            final int index = name.indexOf("!");
            if (index != -1) {

                // Used to be this, modified by Erik Sanders to work
                // with jdk 1.4 plugin
                // String jarFileName =
                // name.substring(name.indexOf(":") + 1, index);

                // changed to this...
                String jarFileName;

                if (name.startsWith("file:")) {
                    // java-plugin 1.3 returns local file: strip file:
                    // from string
                    jarFileName = name.substring(name.indexOf(":") + 1, index);
                } else {
                    // java-plugin 1.4 returns reference to server, so
                    // leave http:// part

                    // Used to start the substring from 1, but changed
                    // to 0 thanks to DGK
                    jarFileName = name.substring(0, index);
                }

                // skip !/ "
                final String jarEntryName = name.substring(index + 2);
                if (Debug.debugging("binaryfile")) {
                    Debug.output(" got: \n" + jarFileName + "\n" + jarEntryName);
                }

                // If the jar doesn't exist, should return something
                // that indicates this. Should check the performance
                // impllications of this call, though, at some point.

                // DGK added
                final File f = new File(jarFileName); 
                if (f.exists() == false) {
                    return false; 
                }
                
                setInputReader(new JarInputReader(jarFileName, jarEntryName));
                return true;
            }
        } catch (final java.security.AccessControlException ace) {
            if (Debug.debugging("binaryfile")) {
                Debug.output("BinaryFile.setJarInputFile: AccessControlException for "
                        + name);
            }
        }

        return false;
    }

    /**
     * A simple test method to determine if a file or directory,
     * represented by a string, can be found by the current Java
     * environment. Uses the same tests as BinaryFile constructor for
     * tracking down a file.
     * 
     * @param name A path to a file, a URL, or a path to a jar file
     *        entry.
     */
    public static boolean exists(final String name) {
        boolean exists = false;
        try {
            File file = null;
            URL url = null;

            if (!Environment.isApplet()) {
                file = new File(name);
            }

            if (file != null && file.exists()) {
                exists = true;
            } else {
                // url = ClassLoader.getSystemResource(name);
                url = Thread.currentThread()
                        .getContextClassLoader()
                        .getResource(name);

                // OK, now we want to look around for the file, in the
                // classpaths, and as a resource. It may be a file in
                // a classpath, available for direct access.
                if (url != null) {
                    exists = true;
                } else if (Environment.isApplet()) {
                    if (Debug.debugging("binaryfile")) {
                        Debug.output(" As applet, checking codebase...");
                    }
                    // Look in the codebase for applets...
                    final URL[] cba = new URL[1];
                    cba[0] = Environment.getApplet().getCodeBase();

                    final URLClassLoader ucl = URLClassLoader.newInstance(cba);
                    if (ucl.getResource(name) != null) {
                        exists = true;

                        // This has been commented out because the
                        // AppletDataNugget has been deprecated, and
                        // is not needed.

                        // } else {
                        // url = AppletDataNugget.findResource(name);

                        // if (url != null) {
                        // exists = true;
                        // }
                    }
                }

                // It's not in the classpath, so try it as a URL to a
                // webserver.
                if (!exists && name.indexOf("http:") != -1) {

                    try {
                        final InputStream stream = new URL(name).openStream();
                        stream.close();
                        exists = true;
                    } catch (final java.security.AccessControlException ace) {
                        exists = false;
                    }
                }
            }

        } catch (final IOException ioe) {
            Debug.message("binaryfile",
                    "BinaryFile.exists() caught IOException");
            exists = false;
        }

        if (Debug.debugging("binaryfile")) {
            Debug.output("BinaryFile.exists(" + name + ") = " + exists);
        }

        return exists;
    }

    /**
     * Get the source name from the input reader.
     */
    public String getName() {
        if (inputReader != null) {
            return inputReader.getName();
        }
        return null;
    }

    /**
     * Get the inputReader used for accessing the file, for quering
     * purposes. Don't use it to get data, or the file pointers may
     * get messed up.
     */
    public InputReader getInputReader() {
        return inputReader;
    }

    /**
     * Set the input reader used by the BinaryFile. Make sure it's
     * intialized properly.
     */
    public void setInputReader(final InputReader reader) {
        if (Debug.debugging("binaryfile")) {
            Debug.output("Setting inputReader");
        }
        inputReader = reader;
    }

    /**
     * Set the byte-ordering used to read shorts, int, etc.
     * 
     * @param msbfirst <code>true</code>= MSB first,
     *        <code>false</code>= LSB first
     */
    public void byteOrder(final boolean msbfirst) {
        MSBFirst = msbfirst;
    }

    /**
     * Accessor for the byte ordering used to read multibyte types.
     * 
     * @return byte ordering
     */
    public boolean byteOrder() {
        return MSBFirst;
    }

    /**
     * Skip over n bytes in the input file
     * 
     * @param n the number of bytes to skip
     * @return the actual number of bytes skipped. annoying, isn't it?
     * @exception IOException Any IO errors that occur in skipping
     *            bytes in the underlying file
     */
    public long skipBytes(final long n) throws IOException {
        return inputReader.skipBytes(n);
    }

    /**
     * Get the index of the next character to be read
     * 
     * @return the index
     * @exception IOException Any IO errors that occur in accessing
     *            the underlying file
     */
    public long getFilePointer() throws IOException {
        return inputReader.getFilePointer();
    }

    /**
     * Set the index of the next character to be read.
     * 
     * @param pos the position to seek to.
     * @exception IOException Any IO Errors that occur in seeking the
     *            underlying file.
     */
    public void seek(final long pos) throws IOException {
        inputReader.seek(pos);
    }

    /**
     * The length of the InputReader source.
     */
    public long length() throws IOException {
        return inputReader.length();
    }

    /**
     * Return how many bytes left to be read in the file.
     * 
     * @return the number of bytes remaining to be read (counted in
     *         bytes)
     * @exception IOException Any IO errors encountered in accessing
     *            the file
     */
    public long available() throws IOException {
        return inputReader.available();
    }

    /**
     * Closes the underlying file
     * 
     * @exception IOException Any IO errors encountered in accessing
     *            the file
     */
    public void close() throws IOException {
        if (inputReader != null) {
            inputReader.close();
        }
        inputReader = null;
    }

    /**
     * Read from the file.
     * 
     * @return one byte from the file. -1 for EOF
     * @exception IOException Any IO errors encountered in reading
     *            from the file
     */
    public int read() throws IOException {
        return inputReader.read();
    }

    /**
     * Read from the file
     * 
     * @param b The byte array to read into
     * @param off the first array position to read into
     * @param len the number of bytes to read
     * @return the number of bytes read
     * @exception IOException Any IO errors encountered in reading
     *            from the file
     */
    public int read(final byte b[], final int off, final int len) throws IOException {
        return inputReader.read(b, off, len);
    }

    /**
     * Read from the file.
     * 
     * @param b the byte array to read into. Equivelent to
     *        <code>read(b, 0, b.length)</code>
     * @return the number of bytes read
     * @exception IOException Any IO errors encountered in reading
     *            from the file
     * @see java.io.RandomAccessFile#read(byte[])
     */
    public int read(final byte b[]) throws IOException {
        return inputReader.read(b);
    }

    /**
     * Read from the file.
     * 
     * @param howmany the number of bytes to read
     * @param allowless if we can return fewer bytes than requested
     * @return the array of bytes read.
     * @exception FormatException Any IO Exceptions, plus an
     *            end-of-file encountered after reading some, but now
     *            enough, bytes when allowless was <code>false</code>
     * @exception EOFException Encountered an end-of-file while
     *            allowless was <code>false</code>, but NO bytes
     *            had been read.
     */
    public byte[] readBytes(final int howmany, final boolean allowless)
            throws EOFException, FormatException {

        return inputReader.readBytes(howmany, allowless);
    }

    /**
     * Reads and returns a single byte, cast to a char
     * 
     * @return the byte read from the file, cast to a char
     * @exception EOFException the end-of-file has been reached, so no
     *            chars where available
     * @exception FormatException a rethrown IOException
     */
    public char readChar() throws EOFException, FormatException {
        try {
            final int retv = inputReader.read();

            if (retv == -1) {
                throw new EOFException("Error in ReadChar, EOF reached");
            }
            return (char) retv;
        } catch (final IOException i) {
            throw new FormatException("readChar IOException: " + i.getMessage());
        }
    }

    /**
     * Reads and returns a short.
     * 
     * @return the 2 bytes merged into a short, according to the
     *         current byte ordering
     * @exception EOFException there were less than 2 bytes left in
     *            the file
     * @exception FormatException rethrow of IOExceptions encountered
     *            while reading the bytes for the short
     * @see #read(byte[])
     */
    public short readShort() throws EOFException, FormatException {
        // MSBFirst must be set when we are called
        return MoreMath.BuildShort(readBytes(2, false), MSBFirst);
    }

    /**
     * Reads and returns a long
     * 
     * @return the 4 bytes merged into a long, according to the
     *         current byte ordering
     * @exception EOFException there were less than 4 bytes left in
     *            the file
     * @exception FormatException rethrow of IOExceptions encountered
     *            while reading the bytes for the integer
     * @see #read(byte[])
     */
    public int readInteger() throws EOFException, FormatException {
        // MSBFirst must be set when we are called
        return MoreMath.BuildInteger(readBytes(4, false), MSBFirst);
    }

    public void readIntegerArray(final int vec[], final int offset, final int len)
            throws EOFException, FormatException {
    	int idx = offset;
        for (int i = 0; i < len; i++) {
            vec[idx++] = readInteger();
        }
    }

    /**
     * Reads and returns a long
     * 
     * @return the 8 bytes merged into a long, according to the
     *         current byte ordering
     * @exception EOFException there were less than 8 bytes left in
     *            the file
     * @exception FormatException rethrow of IOExceptions encountered
     *            while reading the bytes for the long
     * @see #read(byte[])
     */
    public long readLong() throws EOFException, FormatException {
        return MoreMath.BuildLong(readBytes(8, false), MSBFirst);
    }

    /**
     * Reads and returns a float
     * 
     * @return the 4 bytes merged into a float, according to the
     *         current byte ordering
     * @exception EOFException there were less than 4 bytes left in
     *            the file
     * @exception FormatException rethrow of IOExceptions encountered
     *            while reading the bytes for the float
     * @see #read(byte[])
     */
    public float readFloat() throws EOFException, FormatException {
        return Float.intBitsToFloat(readInteger());
    }

    public void readFloatArray(final float vec[], final int offset, final int len)
            throws EOFException, FormatException {
    	int idx = offset;
        for (int i = 0; i < len; i++) {
            vec[idx++] = readFloat();
        }
    }

    /**
     * Reads and returns a double
     * 
     * @return the 8 bytes merged into a double, according to the
     *         current byte ordering
     * @exception EOFException there were less than 8 bytes left in
     *            the file
     * @exception FormatException rethrow of IOExceptions encountered
     *            while reading the bytes for the short
     * @see #read(byte[])
     */
    public double readDouble() throws EOFException, FormatException {
        return Double.longBitsToDouble(readLong());
    }

    /**
     * Reads <code>length</code> bytes and returns a string composed
     * of the bytes cast to chars
     * 
     * @param length the number of bytes to read into the string
     * @return the composed string
     * @exception EOFException there were less than
     *            <code>length</code> bytes left in the file
     * @exception FormatException rethrow of IOExceptions encountered
     *            while reading the bytes for the short
     */
    public String readFixedLengthString(final int length) throws EOFException,
            FormatException {

        final byte foo[] = readBytes(length, false);
        return new String(foo, 0, length);
    }

    /**
     * Read a bytes and throw an InvalidCharException if it doesn't
     * match <code>expected</code>
     * 
     * @param expected what the next char is claimed to be
     * @exception EOFException there wasn't a byte, so we can't check
     *            for a match
     * @exception InvalidCharException throws when the character read
     *            doesn't match <code>expected</code> The .c member
     *            of the thrown exception is the actual char read
     * @exception FormatException some other error from reading the
     *            file
     */
    public void assertChar(final char expected) throws EOFException, FormatException {
        final char c = readChar();
        if (c != expected) {
            throw new InvalidCharException("AssertChar: expected " + expected
                    + " got " + c, c);
        }
    }

    /**
     * Reads a string until the specified delimiter or EOF is
     * encountered
     * 
     * @param delim the end-of-string delimiter
     * @return the string that was read
     * @exception FormatException rethrow of IOExceptions from the
     *            read methods
     */
    public String readToDelimiter(final char delim) throws FormatException {
        final StringBuffer buildretval = new StringBuffer();
        char tmp;
        try {
            while ((tmp = readChar()) != delim)
                buildretval.append(tmp);
        } catch (final EOFException e) {
            // allowable
        } catch (final FormatException fe) {
            if (buildretval.length() == 0) {
                throw fe;
            }
        }
        return buildretval.toString();
    }

    /**
     * Makes sure that the file has been closed.
     * 
     * @exception Throwable what it throws.
     */
    public void finalize() throws Throwable {
        close();
    }

    /**
     * Maintains a list of objects that can be closed so that other
     * files can be opened.
     */
    private static Vector<WeakReference<Closable>> closableList = new Vector<WeakReference<Closable>>();

    /**
     * Add an object that can be closed if needed. Duplicates are
     * allowed. Only holds a WeakReference, so that the object can
     * still be garbage-collected.
     * 
     * @param it the object that can be closed
     */
    public static synchronized void addClosable(final Closable it) {
        closableList.add(new WeakReference<Closable>(it));
    }

    /**
     * Remove an object from the closable list.
     * 
     * @param it the object to remove
     */
    public static synchronized void removeClosable(final Closable it) {
        for (int i = 0; i < closableList.size(); i++) {
            final Object o = ((WeakReference<Closable>) closableList.elementAt(i)).get();
            if ((o == it) || (o == null)) {
                closableList.removeElementAt(i);
                i--; // in case its in the list more than once
            }
        }
    }

    public static synchronized void closeClosable() {
        System.out.println("closeClosable " + closableList.size());
        for (int i = 0; i < closableList.size(); i++) {
            final Closable c = (Closable) (closableList.elementAt(i)).get();
            if ((c == null) || !c.close(false)) {
                closableList.removeElementAt(i);
                i--;
            }
        }
    }
}