| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (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.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package java.io; |
| |
| import org.apache.harmony.luni.util.Msg; |
| import org.apache.harmony.luni.util.Util; |
| |
| /** |
| * Wraps an existing {@link InputStream} and reads typed data from it. |
| * Typically, this stream has been written by a DataOutputStream. Types that can |
| * be read include byte, 16-bit short, 32-bit int, 32-bit float, 64-bit long, |
| * 64-bit double, byte strings, and strings encoded in |
| * {@link DataInput modified UTF-8}. |
| * |
| * @see DataOutputStream |
| */ |
| public class DataInputStream extends FilterInputStream implements DataInput { |
| |
| byte[] buff; |
| |
| /** |
| * Constructs a new DataInputStream on the InputStream {@code in}. All |
| * reads are then filtered through this stream. Note that data read by this |
| * stream is not in a human readable format and was most likely created by a |
| * DataOutputStream. |
| * |
| * @param in |
| * the source InputStream the filter reads from. |
| * @see DataOutputStream |
| * @see RandomAccessFile |
| */ |
| public DataInputStream(InputStream in) { |
| super(in); |
| buff = new byte[8]; |
| } |
| |
| /** |
| * Reads bytes from this stream into the byte array {@code buffer}. Returns |
| * the number of bytes that have been read. |
| * |
| * @param buffer |
| * the buffer to read bytes into. |
| * @return the number of bytes that have been read or -1 if the end of the |
| * stream has been reached. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#write(byte[]) |
| * @see DataOutput#write(byte[], int, int) |
| */ |
| @Override |
| public final int read(byte[] buffer) throws IOException { |
| return in.read(buffer, 0, buffer.length); |
| } |
| |
| /** |
| * Reads at most {@code length} bytes from this stream and stores them in |
| * the byte array {@code buffer} starting at {@code offset}. Returns the |
| * number of bytes that have been read or -1 if no bytes have been read and |
| * the end of the stream has been reached. |
| * |
| * @param buffer |
| * the byte array in which to store the bytes read. |
| * @param offset |
| * the initial position in {@code buffer} to store the bytes |
| * read from this stream. |
| * @param length |
| * the maximum number of bytes to store in {@code buffer}. |
| * @return the number of bytes that have been read or -1 if the end of the |
| * stream has been reached. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#write(byte[]) |
| * @see DataOutput#write(byte[], int, int) |
| */ |
| @Override |
| public final int read(byte[] buffer, int offset, int length) |
| throws IOException { |
| return in.read(buffer, offset, length); |
| } |
| |
| /** |
| * Reads a boolean from this stream. |
| * |
| * @return the next boolean value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before one byte |
| * has been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeBoolean(boolean) |
| */ |
| public final boolean readBoolean() throws IOException { |
| int temp = in.read(); |
| if (temp < 0) { |
| throw new EOFException(); |
| } |
| return temp != 0; |
| } |
| |
| /** |
| * Reads an 8-bit byte value from this stream. |
| * |
| * @return the next byte value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before one byte |
| * has been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeByte(int) |
| */ |
| public final byte readByte() throws IOException { |
| int temp = in.read(); |
| if (temp < 0) { |
| throw new EOFException(); |
| } |
| return (byte) temp; |
| } |
| |
| /** |
| * Reads a 16-bit character value from this stream. |
| * |
| * @return the next char value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before two bytes |
| * have been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeChar(int) |
| */ |
| private int readToBuff(int count) throws IOException { |
| int offset = 0; |
| |
| while(offset < count) { |
| int bytesRead = in.read(buff, offset, count - offset); |
| if(bytesRead == -1) return bytesRead; |
| offset += bytesRead; |
| } |
| return offset; |
| } |
| |
| public final char readChar() throws IOException { |
| if (readToBuff(2) < 0){ |
| throw new EOFException(); |
| } |
| return (char) (((buff[0] & 0xff) << 8) | (buff[1] & 0xff)); |
| |
| } |
| |
| /** |
| * Reads a 64-bit double value from this stream. |
| * |
| * @return the next double value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before eight |
| * bytes have been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeDouble(double) |
| */ |
| public final double readDouble() throws IOException { |
| return Double.longBitsToDouble(readLong()); |
| } |
| |
| /** |
| * Reads a 32-bit float value from this stream. |
| * |
| * @return the next float value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before four |
| * bytes have been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeFloat(float) |
| */ |
| public final float readFloat() throws IOException { |
| return Float.intBitsToFloat(readInt()); |
| } |
| |
| /** |
| * Reads bytes from this stream into the byte array {@code buffer}. This |
| * method will block until {@code buffer.length} number of bytes have been |
| * read. |
| * |
| * @param buffer |
| * to read bytes into. |
| * @throws EOFException |
| * if the end of the source stream is reached before enough |
| * bytes have been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#write(byte[]) |
| * @see DataOutput#write(byte[], int, int) |
| */ |
| public final void readFully(byte[] buffer) throws IOException { |
| readFully(buffer, 0, buffer.length); |
| } |
| |
| /** |
| * Reads bytes from this stream and stores them in the byte array {@code |
| * buffer} starting at the position {@code offset}. This method blocks until |
| * {@code length} bytes have been read. If {@code length} is zero, then this |
| * method returns without reading any bytes. |
| * |
| * @param buffer |
| * the byte array into which the data is read. |
| * @param offset |
| * the offset in {@code buffer} from where to store the bytes |
| * read. |
| * @param length |
| * the maximum number of bytes to read. |
| * @throws EOFException |
| * if the end of the source stream is reached before enough |
| * bytes have been read. |
| * @throws IndexOutOfBoundsException |
| * if {@code offset < 0} or {@code length < 0}, or if {@code |
| * offset + length} is greater than the size of {@code buffer}. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @throws NullPointerException |
| * if {@code buffer} or the source stream are null. |
| * @see java.io.DataInput#readFully(byte[], int, int) |
| */ |
| public final void readFully(byte[] buffer, int offset, int length) |
| throws IOException { |
| if (length < 0) { |
| throw new IndexOutOfBoundsException(); |
| } |
| if (length == 0) { |
| return; |
| } |
| if (in == null) { |
| throw new NullPointerException(Msg.getString("KA00b")); //$NON-NLS-1$ |
| } |
| if (buffer == null) { |
| throw new NullPointerException(Msg.getString("K0047")); //$NON-NLS-1$ |
| } |
| if (offset < 0 || offset > buffer.length - length) { |
| throw new IndexOutOfBoundsException(); |
| } |
| while (length > 0) { |
| int result = in.read(buffer, offset, length); |
| if (result < 0) { |
| throw new EOFException(); |
| } |
| offset += result; |
| length -= result; |
| } |
| } |
| |
| /** |
| * Reads a 32-bit integer value from this stream. |
| * |
| * @return the next int value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before four |
| * bytes have been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeInt(int) |
| */ |
| public final int readInt() throws IOException { |
| if (readToBuff(4) < 0){ |
| throw new EOFException(); |
| } |
| return ((buff[0] & 0xff) << 24) | ((buff[1] & 0xff) << 16) | |
| ((buff[2] & 0xff) << 8) | (buff[3] & 0xff); |
| } |
| |
| /** |
| * Returns a string that contains the next line of text available from the |
| * source stream. A line is represented by zero or more characters followed |
| * by {@code '\n'}, {@code '\r'}, {@code "\r\n"} or the end of the stream. |
| * The string does not include the newline sequence. |
| * |
| * @return the contents of the line or {@code null} if no characters were |
| * read before the end of the source stream has been reached. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @deprecated Use {@link BufferedReader} |
| */ |
| @Deprecated |
| public final String readLine() throws IOException { |
| StringBuilder line = new StringBuilder(80); // Typical line length |
| boolean foundTerminator = false; |
| while (true) { |
| int nextByte = in.read(); |
| switch (nextByte) { |
| case -1: |
| if (line.length() == 0 && !foundTerminator) { |
| return null; |
| } |
| return line.toString(); |
| case (byte) '\r': |
| if (foundTerminator) { |
| ((PushbackInputStream) in).unread(nextByte); |
| return line.toString(); |
| } |
| foundTerminator = true; |
| /* Have to be able to peek ahead one byte */ |
| if (!(in.getClass() == PushbackInputStream.class)) { |
| in = new PushbackInputStream(in); |
| } |
| break; |
| case (byte) '\n': |
| return line.toString(); |
| default: |
| if (foundTerminator) { |
| ((PushbackInputStream) in).unread(nextByte); |
| return line.toString(); |
| } |
| line.append((char) nextByte); |
| } |
| } |
| } |
| |
| /** |
| * Reads a 64-bit long value from this stream. |
| * |
| * @return the next long value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before eight |
| * bytes have been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeLong(long) |
| */ |
| public final long readLong() throws IOException { |
| if (readToBuff(8) < 0){ |
| throw new EOFException(); |
| } |
| int i1 = ((buff[0] & 0xff) << 24) | ((buff[1] & 0xff) << 16) | |
| ((buff[2] & 0xff) << 8) | (buff[3] & 0xff); |
| int i2 = ((buff[4] & 0xff) << 24) | ((buff[5] & 0xff) << 16) | |
| ((buff[6] & 0xff) << 8) | (buff[7] & 0xff); |
| |
| return ((i1 & 0xffffffffL) << 32) | (i2 & 0xffffffffL); |
| } |
| |
| /** |
| * Reads a 16-bit short value from this stream. |
| * |
| * @return the next short value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before two bytes |
| * have been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeShort(int) |
| */ |
| public final short readShort() throws IOException { |
| if (readToBuff(2) < 0){ |
| throw new EOFException(); |
| } |
| return (short) (((buff[0] & 0xff) << 8) | (buff[1] & 0xff)); |
| } |
| |
| /** |
| * Reads an unsigned 8-bit byte value from this stream and returns it as an |
| * int. |
| * |
| * @return the next unsigned byte value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream has been reached before one |
| * byte has been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeByte(int) |
| */ |
| public final int readUnsignedByte() throws IOException { |
| int temp = in.read(); |
| if (temp < 0) { |
| throw new EOFException(); |
| } |
| return temp; |
| } |
| |
| /** |
| * Reads a 16-bit unsigned short value from this stream and returns it as an |
| * int. |
| * |
| * @return the next unsigned short value from the source stream. |
| * @throws EOFException |
| * if the end of the filtered stream is reached before two bytes |
| * have been read. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeShort(int) |
| */ |
| public final int readUnsignedShort() throws IOException { |
| if (readToBuff(2) < 0){ |
| throw new EOFException(); |
| } |
| return (char) (((buff[0] & 0xff) << 8) | (buff[1] & 0xff)); |
| } |
| |
| /** |
| * Reads an string encoded in {@link DataInput modified UTF-8} from this |
| * stream. |
| * |
| * @return the next {@link DataInput MUTF-8} encoded string read from the |
| * source stream. |
| * @throws EOFException if the end of the input is reached before the read |
| * request can be satisfied. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutput#writeUTF(java.lang.String) |
| */ |
| public final String readUTF() throws IOException { |
| return decodeUTF(readUnsignedShort()); |
| } |
| |
| |
| String decodeUTF(int utfSize) throws IOException { |
| return decodeUTF(utfSize, this); |
| } |
| |
| private static String decodeUTF(int utfSize, DataInput in) throws IOException { |
| byte[] buf = new byte[utfSize]; |
| char[] out = new char[utfSize]; |
| in.readFully(buf, 0, utfSize); |
| |
| return Util.convertUTF8WithBuf(buf, out, 0, utfSize); |
| } |
| |
| /** |
| * Reads a string encoded in {@link DataInput modified UTF-8} from the |
| * {@code DataInput} stream {@code in}. |
| * |
| * @param in |
| * the input stream to read from. |
| * @return the next {@link DataInput MUTF-8} encoded string from the source |
| * stream. |
| * @throws IOException |
| * if a problem occurs while reading from this stream. |
| * @see DataOutputStream#writeUTF(java.lang.String) |
| */ |
| public static final String readUTF(DataInput in) throws IOException { |
| return decodeUTF(in.readUnsignedShort(), in); |
| } |
| |
| /** |
| * Skips {@code count} number of bytes in this stream. Subsequent {@code |
| * read()}s will not return these bytes unless {@code reset()} is used. |
| * |
| * This method will not throw an {@link EOFException} if the end of the |
| * input is reached before {@code count} bytes where skipped. |
| * |
| * @param count |
| * the number of bytes to skip. |
| * @return the number of bytes actually skipped. |
| * @throws IOException |
| * if a problem occurs during skipping. |
| * @see #mark(int) |
| * @see #reset() |
| */ |
| public final int skipBytes(int count) throws IOException { |
| int skipped = 0; |
| long skip; |
| while (skipped < count && (skip = in.skip(count - skipped)) != 0) { |
| skipped += skip; |
| } |
| if (skipped < 0) { |
| throw new EOFException(); |
| } |
| return skipped; |
| } |
| } |