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**** BEGIN LICENSE BLOCK ***** Version: CPL 1.0/GPL 2.0/LGPL 2.1 The contents of this file are subject to the Common Public License Version 1.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.eclipse.org/legal/cpl-v10.html Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License. Copyright (C) 2009-2010 Yoko Harada <yokolet@gmail.com> Alternatively, the contents of this file may be used under the terms of either of the GNU General Public License Version 2 or later (the "GPL"), or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), in which case the provisions of the GPL or the LGPL are applicable instead of those above. If you wish to allow use of your version of this file only under the terms of either the GPL or the LGPL, and not to allow others to use your version of this file under the terms of the CPL, indicate your decision by deleting the provisions above and replace them with the notice and other provisions required by the GPL or the LGPL. If you do not delete the provisions above, a recipient may use your version of this file under the terms of any one of the CPL, the GPL or the LGPL. **** END LICENSE BLOCK *****
 
 package org.jruby.embed.io;
 
 import java.io.Reader;
 import java.util.List;

A ReaderInputStream converts java.io.Reader to java.io.InputStream. The ReaderInputStream reads data in a given Reader object into its internal buffer so that users of this class can access the file that Reader read by using methods defined in java.io.InputStream.

Author(s):
Yoko Harada <yokolet@gmail.com>
 
 public class ReaderInputStream extends InputStream {
 
     private static final int DEFAULT_CHAR_BUFFER_SIZE = 8192;
     private static final int DEFAULT_BYTE_BUFFER_SIZE = 8192;
     private final Reader reader;
     private byte[] bytes = null;
     private int totalBytes = 0;
     private int position = 0;
     private int markedIndex = -1;
     private int readlimit = 0;
     private boolean isOpen = true;
     private CharsetEncoder encoder;
     private final Object lock = new Object();

    
Creates ReaderInputStream from a given Reader type object with a default encoding.

Parameters:
reader java.io.Reader object to be read data from.
 
     public ReaderInputStream(Reader reader) {
         this(readernull);
     }

    
Creates ReaderInputStream from a given Reader type object with a specifed encoding.

Parameters:
reader java.io.Reader object to be read data from.
encoding an encoding of the created stream.
 
     public ReaderInputStream(Reader readerString encoding) {
         this. = reader;
         if (encoding == null) {
             if (reader instanceof InputStreamReader) {
                 encoding = ((InputStreamReaderreader).getEncoding();
             } else {
                 encoding = Charset.defaultCharset().name();
             }
         } else if (!Charset.isSupported(encoding)) {
             throw new IllegalArgumentException(encoding + " is not supported");
         }
          = Charset.forName(encoding).newEncoder();
         try {
             fillByteBuffer(reader);
         } catch (IOException ex) {
             throw new RuntimeException(ex);
        }
    }
    private void fillByteBuffer(Reader readerthrows IOException {
        CharBuffer cbuf = CharBuffer.allocate();
        ByteBuffer bbuf = ByteBuffer.allocate();
        List<byte[]> list = new ArrayList<byte[]>();
        while (true) {
            cbuf.clear();
            int size = reader.read(cbuf);
            if (size <= 0) {
                break;
            }
            cbuf.limit(cbuf.position());
            cbuf.rewind();
            boolean eof = false;
            while (!eof) {
                CoderResult cr = .encode(cbufbbufeof);
                if (cr.isError()) {
                    cr.throwException();
                } else if (cr.isUnderflow()) {
                    appendBytes(listbbuf);
                    eof = true;
                } else if (cr.isOverflow()) {
                    appendBytes(listbbuf);
                    bbuf.clear();
                }
            }
        }
        getByteArray(list);
    }
    private void appendBytes(List<byte[]> listByteBuffer bb) {
        bb.flip();
        int length = bb.limit();
         += length;
        byte[] dst = new byte[length];
        System.arraycopy(bb.array(), bb.position(), dst, 0, length);
        list.add(dst);
    }
    private void getByteArray(List<byte[]> list) {
         = new byte[];
        int index = 0;
        for (byte[] bb : list) {
            for (int i=0; i<bb.lengthi++) {
                [index++] = bb[i];
            }
        }
    }
    private void confirmOpen() throws IOException {
        if (!) {
            throw new IOException("This stream has been closed.");
        }
    }

    
Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking by the next invocation of a method for this input stream. The next invocation might be the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

Note that while some implementations of InputStream will return the total number of bytes in the stream, many will not. It is never correct to use the return value of this method to allocate a buffer intended to hold all data in this stream.

A subclass' implementation of this method may choose to throw an java.io.IOException if this input stream has been closed by invoking the close() method.

The available method for class InputStream always returns 0.

Returns:
an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream.
Throws:
java.io.IOException if an I/O error occurs.
    @Override
    public int available() throws IOException {
        synchronized () {
            confirmOpen();
            if ( == null) {
                throw new IOException("This stream is not available.");
            }
            return  - ;
        }
    }

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

Throws:
java.io.IOException if an I/O error occurs.
    @Override
    public void close() throws IOException {
        synchronized () {
            confirmOpen();
             = false;
             = null;
             = null;
            //reader.close();
        }
    }

    
Marks the current position in this input stream. A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.

The readlimit arguments tells this input stream to allow that many bytes to be read before the mark position gets invalidated.

The general contract of mark is that, if the method markSupported returns true, the stream somehow remembers all the bytes read after the call to mark and stands ready to supply those same bytes again if and whenever the method reset is called. However, the stream is not required to remember any data at all if more than readlimit bytes are read from the stream before reset is called.

Marking a closed stream should not have any effect on the stream.

The mark method of InputStream does nothing.

Parameters:
readlimit the maximum limit of bytes that can be read before the mark position becomes invalid.
See also:
java.io.InputStream.reset()
    @Override
    public synchronized void mark(int readlimit) {
        if (readlimit < 0) {
            throw new IllegalArgumentException("Read limit < 0");
        }
        synchronized () {
            if () {
                this. = readlimit;
                 = ;
            }
        }
    }

    
Tests if this input stream supports the mark and reset methods. Whether or not mark and reset are supported is an invariant property of a particular input stream instance.

Returns:
true if this stream instance supports the mark and reset methods; false otherwise.
See also:
java.io.InputStream.mark(int)
java.io.InputStream.reset()
    @Override
    public boolean markSupported() {
        return true;
    }

    
Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

A subclass must provide an implementation of this method.

Returns:
the next byte of data, or -1 if the end of the stream is reached.
Throws:
java.io.IOException if an I/O error occurs.
    @Override
    public int read() throws IOException {
        synchronized () {
            confirmOpen();
            if ( >= ) {
                return -1;
            } else {
                return [++];
            }
        }
    }

    
Reads some number of bytes from the input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

If the length of b is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at the end of the file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[0], the next one into b[1], and so on. The number of bytes read is, at most, equal to the length of b. Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected.

The read(b) method for class InputStream has the same effect as:

 read(b, 0, b.length) 

Parameters:
b the buffer into which the data is read.
Returns:
the total number of bytes read into the buffer, or -1 is there is no more data because the end of the stream has been reached.
Throws:
java.io.IOException If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.
java.lang.NullPointerException if b is null.
See also:
java.io.InputStream.read(byte[],int,int)
    @Override
    public int read(byte[] bthrows IOException {
        return read(b, 0, b.length);
    }

    
Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.

This method blocks until input data is available, end of file is detected, or an exception is thrown.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

In every case, elements b[0] through b[off] and elements b[off+len] through b[b.length-1] are unaffected.

The read(b, off, len) method for class InputStream simply calls the method read() repeatedly. If the first such call results in an IOException, that exception is returned from the call to the read(b, off, len) method. If any subsequent call to read() results in a IOException, the exception is caught and treated as if it were end of file; the bytes read up to that point are stored into b and the number of bytes read before the exception occurred is returned. The default implementation of this method blocks until the requested amount of input data len has been read, end of file is detected, or an exception is thrown. Subclasses are encouraged to provide a more efficient implementation of this method.

Parameters:
b the buffer into which the data is read.
off the start offset in array b at which the data is written.
len the maximum number of bytes to read.
Returns:
the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.
Throws:
java.io.IOException If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.
java.lang.NullPointerException If b is null.
java.lang.IndexOutOfBoundsException If off is negative, len is negative, or len is greater than b.length - off
See also:
java.io.InputStream.read()
    @Override
    public int read(byte[] bint offint lenthrows IOException {
        synchronized () {
            confirmOpen();
            if (len == 0) {
                return 0;
            }
            if ( >= ) {
                return -1;
            }
            if (off < 0 || off >  || len < 0) {
                throw new IllegalArgumentException("Either one of, or both of off and len are invalid.");
            }
            int start =  + off;
            start = start <  ? start :  - 1;
            int end = start + len;
            end = end <  ? end :  - 1;
            int actuallyRead = Math.min((end - start) + 1, len);
            System.arraycopy(startb, 0, actuallyRead);
             += actuallyRead;
            return actuallyRead;
        }
    }

    
Repositions this stream to the position at the time the mark method was last called on this input stream.

The general contract of reset is:

  • If the method markSupported returns true, then:
    • If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown.
    • If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.
  • If the method markSupported returns false, then:
    • The call to reset may throw an IOException.
    • If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.

Throws:
java.io.IOException if this stream has not been marked or if the mark has been invalidated.
See also:
java.io.InputStream.mark(int)
java.io.IOException
    @Override
    public synchronized void reset() throws IOException {
        synchronized () {
            if (!) {
                throw new IOException("This stream has been closed.");
            }
            if ( < 0) {
                throw new IOException("This stream is not marked.");
            }
            if (( - ) > ) {
                throw new IOException("Mark is invalidated.");
            }
             = ;
        }
    }

    
Skips over and discards n bytes of data from this input stream. The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned. If n is negative, no bytes are skipped.

Parameters:
n the number of bytes to be skipped.
Returns:
the actual number of bytes skipped.
Throws:
java.io.IOException if the stream does not support seek, or if some other I/O error occurs.
    @Override
    public long skip(long nthrows IOException {
        if (n < 0L) {
            throw new IllegalArgumentException("Negarive skip");
        }
        synchronized () {
            if (!) {
                throw new IOException("This stream has been closed.");
            }
            long skipped;
            if (( - ) < n) {
                skipped =  - ;
                 = ;
            } else {
                skipped = n;
                 += n;
            }
            return skipped;
        }
    }
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