| /* |
| * Copyright (c) 1994, 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.io; |
| |
| /** |
| * A data input stream lets an application read primitive Java data |
| * types from an underlying input stream in a machine-independent |
| * way. An application uses a data output stream to write data that |
| * can later be read by a data input stream. |
| * <p> |
| * DataInputStream is not necessarily safe for multithreaded access. |
| * Thread safety is optional and is the responsibility of users of |
| * methods in this class. |
| * |
| * @author Arthur van Hoff |
| * @see java.io.DataOutputStream |
| * @since JDK1.0 |
| */ |
| public |
| class DataInputStream extends FilterInputStream implements DataInput { |
| |
| /** |
| * Creates a DataInputStream that uses the specified |
| * underlying InputStream. |
| * |
| * @param in the specified input stream |
| */ |
| public DataInputStream(InputStream in) { |
| super(in); |
| } |
| |
| /** |
| * working arrays initialized on demand by readUTF |
| */ |
| private byte bytearr[] = new byte[80]; |
| private char chararr[] = new char[80]; |
| |
| /** |
| * Reads some number of bytes from the contained input stream and |
| * stores them into the buffer array <code>b</code>. 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. |
| * |
| * <p>If <code>b</code> is null, a <code>NullPointerException</code> is |
| * thrown. If the length of <code>b</code> is zero, then no bytes are |
| * read and <code>0</code> 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 <code>-1</code> is returned; |
| * otherwise, at least one byte is read and stored into <code>b</code>. |
| * |
| * <p>The first byte read is stored into element <code>b[0]</code>, the |
| * next one into <code>b[1]</code>, and so on. The number of bytes read |
| * is, at most, equal to the length of <code>b</code>. Let <code>k</code> |
| * be the number of bytes actually read; these bytes will be stored in |
| * elements <code>b[0]</code> through <code>b[k-1]</code>, leaving |
| * elements <code>b[k]</code> through <code>b[b.length-1]</code> |
| * unaffected. |
| * |
| * <p>The <code>read(b)</code> method has the same effect as: |
| * <blockquote><pre> |
| * read(b, 0, b.length) |
| * </pre></blockquote> |
| * |
| * @param b the buffer into which the data is read. |
| * @return the total number of bytes read into the buffer, or |
| * <code>-1</code> if there is no more data because the end |
| * of the stream has been reached. |
| * @exception IOException if the first byte cannot be read for any reason |
| * other than end of file, the stream has been closed and the underlying |
| * input stream does not support reading after close, or another I/O |
| * error occurs. |
| * @see java.io.FilterInputStream#in |
| * @see java.io.InputStream#read(byte[], int, int) |
| */ |
| public final int read(byte b[]) throws IOException { |
| return in.read(b, 0, b.length); |
| } |
| |
| /** |
| * Reads up to <code>len</code> bytes of data from the contained |
| * input stream into an array of bytes. An attempt is made to read |
| * as many as <code>len</code> bytes, but a smaller number may be read, |
| * possibly zero. The number of bytes actually read is returned as an |
| * integer. |
| * |
| * <p> This method blocks until input data is available, end of file is |
| * detected, or an exception is thrown. |
| * |
| * <p> If <code>len</code> is zero, then no bytes are read and |
| * <code>0</code> 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 <code>-1</code> is returned; otherwise, at least one |
| * byte is read and stored into <code>b</code>. |
| * |
| * <p> The first byte read is stored into element <code>b[off]</code>, the |
| * next one into <code>b[off+1]</code>, and so on. The number of bytes read |
| * is, at most, equal to <code>len</code>. Let <i>k</i> be the number of |
| * bytes actually read; these bytes will be stored in elements |
| * <code>b[off]</code> through <code>b[off+</code><i>k</i><code>-1]</code>, |
| * leaving elements <code>b[off+</code><i>k</i><code>]</code> through |
| * <code>b[off+len-1]</code> unaffected. |
| * |
| * <p> In every case, elements <code>b[0]</code> through |
| * <code>b[off]</code> and elements <code>b[off+len]</code> through |
| * <code>b[b.length-1]</code> are unaffected. |
| * |
| * @param b the buffer into which the data is read. |
| * @param off the start offset in the destination array <code>b</code> |
| * @param len the maximum number of bytes read. |
| * @return the total number of bytes read into the buffer, or |
| * <code>-1</code> if there is no more data because the end |
| * of the stream has been reached. |
| * @exception NullPointerException If <code>b</code> is <code>null</code>. |
| * @exception IndexOutOfBoundsException If <code>off</code> is negative, |
| * <code>len</code> is negative, or <code>len</code> is greater than |
| * <code>b.length - off</code> |
| * @exception IOException if the first byte cannot be read for any reason |
| * other than end of file, the stream has been closed and the underlying |
| * input stream does not support reading after close, or another I/O |
| * error occurs. |
| * @see java.io.FilterInputStream#in |
| * @see java.io.InputStream#read(byte[], int, int) |
| */ |
| public final int read(byte b[], int off, int len) throws IOException { |
| return in.read(b, off, len); |
| } |
| |
| /** |
| * See the general contract of the <code>readFully</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @param b the buffer into which the data is read. |
| * @exception EOFException if this input stream reaches the end before |
| * reading all the bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final void readFully(byte b[]) throws IOException { |
| readFully(b, 0, b.length); |
| } |
| |
| /** |
| * See the general contract of the <code>readFully</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @param b the buffer into which the data is read. |
| * @param off the start offset of the data. |
| * @param len the number of bytes to read. |
| * @exception EOFException if this input stream reaches the end before |
| * reading all the bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final void readFully(byte b[], int off, int len) throws IOException { |
| if (len < 0) |
| throw new IndexOutOfBoundsException(); |
| int n = 0; |
| while (n < len) { |
| int count = in.read(b, off + n, len - n); |
| if (count < 0) |
| throw new EOFException(); |
| n += count; |
| } |
| } |
| |
| /** |
| * See the general contract of the <code>skipBytes</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes for this operation are read from the contained |
| * input stream. |
| * |
| * @param n the number of bytes to be skipped. |
| * @return the actual number of bytes skipped. |
| * @exception IOException if the contained input stream does not support |
| * seek, or the stream has been closed and |
| * the contained input stream does not support |
| * reading after close, or another I/O error occurs. |
| */ |
| public final int skipBytes(int n) throws IOException { |
| int total = 0; |
| int cur = 0; |
| |
| while ((total<n) && ((cur = (int) in.skip(n-total)) > 0)) { |
| total += cur; |
| } |
| |
| return total; |
| } |
| |
| /** |
| * See the general contract of the <code>readBoolean</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes for this operation are read from the contained |
| * input stream. |
| * |
| * @return the <code>boolean</code> value read. |
| * @exception EOFException if this input stream has reached the end. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final boolean readBoolean() throws IOException { |
| int ch = in.read(); |
| if (ch < 0) |
| throw new EOFException(); |
| return (ch != 0); |
| } |
| |
| /** |
| * See the general contract of the <code>readByte</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next byte of this input stream as a signed 8-bit |
| * <code>byte</code>. |
| * @exception EOFException if this input stream has reached the end. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final byte readByte() throws IOException { |
| int ch = in.read(); |
| if (ch < 0) |
| throw new EOFException(); |
| return (byte)(ch); |
| } |
| |
| /** |
| * See the general contract of the <code>readUnsignedByte</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next byte of this input stream, interpreted as an |
| * unsigned 8-bit number. |
| * @exception EOFException if this input stream has reached the end. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final int readUnsignedByte() throws IOException { |
| int ch = in.read(); |
| if (ch < 0) |
| throw new EOFException(); |
| return ch; |
| } |
| |
| /** |
| * See the general contract of the <code>readShort</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next two bytes of this input stream, interpreted as a |
| * signed 16-bit number. |
| * @exception EOFException if this input stream reaches the end before |
| * reading two bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final short readShort() throws IOException { |
| int ch1 = in.read(); |
| int ch2 = in.read(); |
| if ((ch1 | ch2) < 0) |
| throw new EOFException(); |
| return (short)((ch1 << 8) + (ch2 << 0)); |
| } |
| |
| /** |
| * See the general contract of the <code>readUnsignedShort</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next two bytes of this input stream, interpreted as an |
| * unsigned 16-bit integer. |
| * @exception EOFException if this input stream reaches the end before |
| * reading two bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final int readUnsignedShort() throws IOException { |
| int ch1 = in.read(); |
| int ch2 = in.read(); |
| if ((ch1 | ch2) < 0) |
| throw new EOFException(); |
| return (ch1 << 8) + (ch2 << 0); |
| } |
| |
| /** |
| * See the general contract of the <code>readChar</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next two bytes of this input stream, interpreted as a |
| * <code>char</code>. |
| * @exception EOFException if this input stream reaches the end before |
| * reading two bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final char readChar() throws IOException { |
| int ch1 = in.read(); |
| int ch2 = in.read(); |
| if ((ch1 | ch2) < 0) |
| throw new EOFException(); |
| return (char)((ch1 << 8) + (ch2 << 0)); |
| } |
| |
| /** |
| * See the general contract of the <code>readInt</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next four bytes of this input stream, interpreted as an |
| * <code>int</code>. |
| * @exception EOFException if this input stream reaches the end before |
| * reading four bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final int readInt() throws IOException { |
| int ch1 = in.read(); |
| int ch2 = in.read(); |
| int ch3 = in.read(); |
| int ch4 = in.read(); |
| if ((ch1 | ch2 | ch3 | ch4) < 0) |
| throw new EOFException(); |
| return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0)); |
| } |
| |
| private byte readBuffer[] = new byte[8]; |
| |
| /** |
| * See the general contract of the <code>readLong</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next eight bytes of this input stream, interpreted as a |
| * <code>long</code>. |
| * @exception EOFException if this input stream reaches the end before |
| * reading eight bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.FilterInputStream#in |
| */ |
| public final long readLong() throws IOException { |
| readFully(readBuffer, 0, 8); |
| return (((long)readBuffer[0] << 56) + |
| ((long)(readBuffer[1] & 255) << 48) + |
| ((long)(readBuffer[2] & 255) << 40) + |
| ((long)(readBuffer[3] & 255) << 32) + |
| ((long)(readBuffer[4] & 255) << 24) + |
| ((readBuffer[5] & 255) << 16) + |
| ((readBuffer[6] & 255) << 8) + |
| ((readBuffer[7] & 255) << 0)); |
| } |
| |
| /** |
| * See the general contract of the <code>readFloat</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next four bytes of this input stream, interpreted as a |
| * <code>float</code>. |
| * @exception EOFException if this input stream reaches the end before |
| * reading four bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.DataInputStream#readInt() |
| * @see java.lang.Float#intBitsToFloat(int) |
| */ |
| public final float readFloat() throws IOException { |
| return Float.intBitsToFloat(readInt()); |
| } |
| |
| /** |
| * See the general contract of the <code>readDouble</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return the next eight bytes of this input stream, interpreted as a |
| * <code>double</code>. |
| * @exception EOFException if this input stream reaches the end before |
| * reading eight bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @see java.io.DataInputStream#readLong() |
| * @see java.lang.Double#longBitsToDouble(long) |
| */ |
| public final double readDouble() throws IOException { |
| return Double.longBitsToDouble(readLong()); |
| } |
| |
| private char lineBuffer[]; |
| |
| /** |
| * See the general contract of the <code>readLine</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @deprecated This method does not properly convert bytes to characters. |
| * As of JDK 1.1, the preferred way to read lines of text is via the |
| * <code>BufferedReader.readLine()</code> method. Programs that use the |
| * <code>DataInputStream</code> class to read lines can be converted to use |
| * the <code>BufferedReader</code> class by replacing code of the form: |
| * <blockquote><pre> |
| * DataInputStream d = new DataInputStream(in); |
| * </pre></blockquote> |
| * with: |
| * <blockquote><pre> |
| * BufferedReader d |
| * = new BufferedReader(new InputStreamReader(in)); |
| * </pre></blockquote> |
| * |
| * @return the next line of text from this input stream. |
| * @exception IOException if an I/O error occurs. |
| * @see java.io.BufferedReader#readLine() |
| * @see java.io.FilterInputStream#in |
| */ |
| @Deprecated |
| public final String readLine() throws IOException { |
| char buf[] = lineBuffer; |
| |
| if (buf == null) { |
| buf = lineBuffer = new char[128]; |
| } |
| |
| int room = buf.length; |
| int offset = 0; |
| int c; |
| |
| loop: while (true) { |
| switch (c = in.read()) { |
| case -1: |
| case '\n': |
| break loop; |
| |
| case '\r': |
| int c2 = in.read(); |
| if ((c2 != '\n') && (c2 != -1)) { |
| if (!(in instanceof PushbackInputStream)) { |
| this.in = new PushbackInputStream(in); |
| } |
| ((PushbackInputStream)in).unread(c2); |
| } |
| break loop; |
| |
| default: |
| if (--room < 0) { |
| buf = new char[offset + 128]; |
| room = buf.length - offset - 1; |
| System.arraycopy(lineBuffer, 0, buf, 0, offset); |
| lineBuffer = buf; |
| } |
| buf[offset++] = (char) c; |
| break; |
| } |
| } |
| if ((c == -1) && (offset == 0)) { |
| return null; |
| } |
| return String.copyValueOf(buf, 0, offset); |
| } |
| |
| /** |
| * See the general contract of the <code>readUTF</code> |
| * method of <code>DataInput</code>. |
| * <p> |
| * Bytes |
| * for this operation are read from the contained |
| * input stream. |
| * |
| * @return a Unicode string. |
| * @exception EOFException if this input stream reaches the end before |
| * reading all the bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @exception UTFDataFormatException if the bytes do not represent a valid |
| * modified UTF-8 encoding of a string. |
| * @see java.io.DataInputStream#readUTF(java.io.DataInput) |
| */ |
| public final String readUTF() throws IOException { |
| return readUTF(this); |
| } |
| |
| /** |
| * Reads from the |
| * stream <code>in</code> a representation |
| * of a Unicode character string encoded in |
| * <a href="DataInput.html#modified-utf-8">modified UTF-8</a> format; |
| * this string of characters is then returned as a <code>String</code>. |
| * The details of the modified UTF-8 representation |
| * are exactly the same as for the <code>readUTF</code> |
| * method of <code>DataInput</code>. |
| * |
| * @param in a data input stream. |
| * @return a Unicode string. |
| * @exception EOFException if the input stream reaches the end |
| * before all the bytes. |
| * @exception IOException the stream has been closed and the contained |
| * input stream does not support reading after close, or |
| * another I/O error occurs. |
| * @exception UTFDataFormatException if the bytes do not represent a |
| * valid modified UTF-8 encoding of a Unicode string. |
| * @see java.io.DataInputStream#readUnsignedShort() |
| */ |
| public final static String readUTF(DataInput in) throws IOException { |
| int utflen = in.readUnsignedShort(); |
| byte[] bytearr = null; |
| char[] chararr = null; |
| if (in instanceof DataInputStream) { |
| DataInputStream dis = (DataInputStream)in; |
| if (dis.bytearr.length < utflen){ |
| dis.bytearr = new byte[utflen*2]; |
| dis.chararr = new char[utflen*2]; |
| } |
| chararr = dis.chararr; |
| bytearr = dis.bytearr; |
| } else { |
| bytearr = new byte[utflen]; |
| chararr = new char[utflen]; |
| } |
| |
| int c, char2, char3; |
| int count = 0; |
| int chararr_count=0; |
| |
| in.readFully(bytearr, 0, utflen); |
| |
| while (count < utflen) { |
| c = (int) bytearr[count] & 0xff; |
| if (c > 127) break; |
| count++; |
| chararr[chararr_count++]=(char)c; |
| } |
| |
| while (count < utflen) { |
| c = (int) bytearr[count] & 0xff; |
| switch (c >> 4) { |
| case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7: |
| /* 0xxxxxxx*/ |
| count++; |
| chararr[chararr_count++]=(char)c; |
| break; |
| case 12: case 13: |
| /* 110x xxxx 10xx xxxx*/ |
| count += 2; |
| if (count > utflen) |
| throw new UTFDataFormatException( |
| "malformed input: partial character at end"); |
| char2 = (int) bytearr[count-1]; |
| if ((char2 & 0xC0) != 0x80) |
| throw new UTFDataFormatException( |
| "malformed input around byte " + count); |
| chararr[chararr_count++]=(char)(((c & 0x1F) << 6) | |
| (char2 & 0x3F)); |
| break; |
| case 14: |
| /* 1110 xxxx 10xx xxxx 10xx xxxx */ |
| count += 3; |
| if (count > utflen) |
| throw new UTFDataFormatException( |
| "malformed input: partial character at end"); |
| char2 = (int) bytearr[count-2]; |
| char3 = (int) bytearr[count-1]; |
| if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80)) |
| throw new UTFDataFormatException( |
| "malformed input around byte " + (count-1)); |
| chararr[chararr_count++]=(char)(((c & 0x0F) << 12) | |
| ((char2 & 0x3F) << 6) | |
| ((char3 & 0x3F) << 0)); |
| break; |
| default: |
| /* 10xx xxxx, 1111 xxxx */ |
| throw new UTFDataFormatException( |
| "malformed input around byte " + count); |
| } |
| } |
| // The number of chars produced may be less than utflen |
| return new String(chararr, 0, chararr_count); |
| } |
| } |
