common-utils/src/main/java/org/warp/commonutils/stream/SafeDataInputStream.java

581 lines
17 KiB
Java

/*
* Copyright (c) 1994, 2019, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
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*/
package org.warp.commonutils.stream;
import java.io.DataInput;
import org.jetbrains.annotations.NotNull;
/**
* 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 1.0
*/
public class SafeDataInputStream extends SafeFilterInputStream implements DataInput {
/**
* Creates a DataInputStream that uses the specified
* underlying InputStream.
*
* @param in the specified input stream
*/
public SafeDataInputStream(SafeInputStream 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}. 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} is null, a {@code NullPointerException} is
* thrown. If the length of {@code b} is zero, then no bytes are
* read and {@code 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 {@code -1} is returned;
* otherwise, at least one byte is read and stored into {@code b}.
*
* <p>The first byte read is stored into element {@code b[0]}, the
* next one into {@code b[1]}, and so on. The number of bytes read
* is, at most, equal to the length of {@code b}. Let {@code k}
* be the number of bytes actually read; these bytes will be stored in
* elements {@code b[0]} through {@code b[k-1]}, leaving
* elements {@code b[k]} through {@code b[b.length-1]}
* unaffected.
*
* <p>The {@code read(b)} 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} if there is no more data because the end
* of the stream has been reached.
* @see SafeFilterInputStream#in
* @see java.io.InputStream#read(byte[], int, int)
*/
public final int read(byte[] b) {
return in.read(b, 0, b.length);
}
/**
* Reads up to {@code len} bytes of data from the contained
* input stream into an array of bytes. An attempt is made to read
* as many as {@code len} 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} is zero, then no bytes are read and
* {@code 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 {@code -1} is returned; otherwise, at least one
* byte is read and stored into {@code b}.
*
* <p> The first byte read is stored into element {@code b[off]}, the
* next one into {@code b[off+1]}, and so on. The number of bytes read
* is, at most, equal to {@code len}. Let <i>k</i> be the number of
* bytes actually read; these bytes will be stored in elements
* {@code b[off]} through {@code b[off+}<i>k</i>{@code -1]},
* leaving elements {@code b[off+}<i>k</i>{@code ]} through
* {@code b[off+len-1]} unaffected.
*
* <p> In every case, elements {@code b[0]} through
* {@code b[off]} and elements {@code b[off+len]} through
* {@code b[b.length-1]} are unaffected.
*
* @param b the buffer into which the data is read.
* @param off the start offset in the destination array {@code b}
* @param len the maximum number of bytes read.
* @return the total number of bytes read into the buffer, or
* {@code -1} if there is no more data because the end
* of the stream has been reached.
* @throws NullPointerException If {@code b} is {@code null}.
* @throws IndexOutOfBoundsException If {@code off} is negative,
* {@code len} is negative, or {@code len} is greater than
* {@code b.length - off}
* @see SafeFilterInputStream#in
* @see java.io.InputStream#read(byte[], int, int)
*/
public final int read(byte[] b, int off, int len) {
return in.read(b, off, len);
}
/**
* See the general contract of the {@code readFully}
* method of {@code DataInput}.
* <p>
* Bytes
* for this operation are read from the contained
* input stream.
*
* @param b the buffer into which the data is read.
* @throws NullPointerException if {@code b} is {@code null}.
* @see SafeFilterInputStream#in
*/
public final void readFully(byte @NotNull [] b) {
readFully(b, 0, b.length);
}
/**
* See the general contract of the {@code readFully}
* method of {@code DataInput}.
* <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 in the data array {@code b}.
* @param len the number of bytes to read.
* @throws NullPointerException if {@code b} is {@code null}.
* @throws IndexOutOfBoundsException if {@code off} is negative,
* {@code len} is negative, or {@code len} is greater than
* {@code b.length - off}.
* @see SafeFilterInputStream#in
*/
public final void readFully(byte @NotNull [] b, int off, int len) {
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 IndexOutOfBoundsException();
n += count;
}
}
/**
* See the general contract of the {@code skipBytes}
* method of {@code DataInput}.
* <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.
*/
public final int skipBytes(int n) {
int total = 0;
int cur;
while ((total<n) && ((cur = (int) in.skip(n-total)) > 0)) {
total += cur;
}
return total;
}
/**
* See the general contract of the {@code readBoolean}
* method of {@code DataInput}.
* <p>
* Bytes for this operation are read from the contained
* input stream.
*
* @return the {@code boolean} value read.
* @see SafeFilterInputStream#in
*/
public final boolean readBoolean() {
int ch = in.read();
if (ch < 0)
throw new IndexOutOfBoundsException();
return (ch != 0);
}
/**
* See the general contract of the {@code readByte}
* method of {@code DataInput}.
* <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}.
* @see SafeFilterInputStream#in
*/
public final byte readByte() {
int ch = in.read();
if (ch < 0)
throw new IndexOutOfBoundsException();
return (byte)(ch);
}
/**
* See the general contract of the {@code readUnsignedByte}
* method of {@code DataInput}.
* <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.
* @see SafeFilterInputStream#in
*/
public final int readUnsignedByte() {
int ch = in.read();
if (ch < 0)
throw new IndexOutOfBoundsException();
return ch;
}
/**
* See the general contract of the {@code readShort}
* method of {@code DataInput}.
* <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.
* @see SafeFilterInputStream#in
*/
public final short readShort() {
int ch1 = in.read();
int ch2 = in.read();
if ((ch1 | ch2) < 0)
throw new IndexOutOfBoundsException();
return (short)((ch1 << 8) + (ch2 << 0));
}
/**
* See the general contract of the {@code readUnsignedShort}
* method of {@code DataInput}.
* <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.
* @see SafeFilterInputStream#in
*/
public final int readUnsignedShort() {
int ch1 = in.read();
int ch2 = in.read();
if ((ch1 | ch2) < 0)
throw new IndexOutOfBoundsException();
return (ch1 << 8) + (ch2 << 0);
}
/**
* See the general contract of the {@code readChar}
* method of {@code DataInput}.
* <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}.
* @see SafeFilterInputStream#in
*/
public final char readChar() {
int ch1 = in.read();
int ch2 = in.read();
if ((ch1 | ch2) < 0)
throw new IndexOutOfBoundsException();
return (char)((ch1 << 8) + (ch2 << 0));
}
/**
* See the general contract of the {@code readInt}
* method of {@code DataInput}.
* <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}.
* @see SafeFilterInputStream#in
*/
public final int readInt() {
int ch1 = in.read();
int ch2 = in.read();
int ch3 = in.read();
int ch4 = in.read();
if ((ch1 | ch2 | ch3 | ch4) < 0)
throw new IndexOutOfBoundsException();
return ((ch1 << 24) + (ch2 << 16) + (ch3 << 8) + (ch4 << 0));
}
private final byte[] readBuffer = new byte[8];
/**
* See the general contract of the {@code readLong}
* method of {@code DataInput}.
* <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}.
* @see SafeFilterInputStream#in
*/
public final long readLong() {
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}
* method of {@code DataInput}.
* <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}.
* @see SafeDataInputStream#readInt()
* @see java.lang.Float#intBitsToFloat(int)
*/
public final float readFloat() {
return Float.intBitsToFloat(readInt());
}
/**
* See the general contract of the {@code readDouble}
* method of {@code DataInput}.
* <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}.
* @see SafeDataInputStream#readLong()
* @see java.lang.Double#longBitsToDouble(long)
*/
public final double readDouble() {
return Double.longBitsToDouble(readLong());
}
private char[] lineBuffer;
/**
* See the general contract of the {@code readLine}
* method of {@code DataInput}.
* <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&nbsp;1.1, the preferred way to read lines of text is via the
* {@code BufferedReader.readLine()} method. Programs that use the
* {@code DataInputStream} class to read lines can be converted to use
* the {@code BufferedReader} class by replacing code of the form:
* <blockquote><pre>
* DataInputStream d =&nbsp;new&nbsp;DataInputStream(in);
* </pre></blockquote>
* with:
* <blockquote><pre>
* BufferedReader d
* =&nbsp;new&nbsp;BufferedReader(new&nbsp;InputStreamReader(in));
* </pre></blockquote>
*
* @return the next line of text from this input stream.
* @see java.io.BufferedReader#readLine()
* @see SafeFilterInputStream#in
*/
@Deprecated
public final String readLine() {
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 SafePushbackInputStream)) {
this.in = new SafePushbackInputStream(in);
}
((SafePushbackInputStream)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}
* method of {@code DataInput}.
* <p>
* Bytes
* for this operation are read from the contained
* input stream.
*
* @return a Unicode string.
* @see SafeDataInputStream#readUTF(SafeDataInputStream)
*/
public final @NotNull String readUTF() {
return readUTF(this);
}
/**
* Reads from the
* stream {@code in} 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}.
* The details of the modified UTF-8 representation
* are exactly the same as for the {@code readUTF}
* method of {@code DataInput}.
*
* @param in a data input stream.
* @return a Unicode string.
* @see SafeDataInputStream#readUnsignedShort()
*/
public static String readUTF(SafeDataInputStream in) {
int utflen = in.readUnsignedShort();
byte[] bytearr;
char[] chararr;
if (in.bytearr.length < utflen){
in.bytearr = new byte[utflen*2];
in.chararr = new char[utflen*2];
}
chararr = in.chararr;
bytearr = in.bytearr;
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 IllegalArgumentException(
"malformed input: partial character at end");
char2 = bytearr[count-1];
if ((char2 & 0xC0) != 0x80)
throw new IllegalArgumentException(
"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 IllegalArgumentException(
"malformed input: partial character at end");
char2 = bytearr[count-2];
char3 = bytearr[count-1];
if (((char2 & 0xC0) != 0x80) || ((char3 & 0xC0) != 0x80))
throw new IllegalArgumentException(
"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 IllegalArgumentException(
"malformed input around byte " + count);
}
}
// The number of chars produced may be less than utflen
return new String(chararr, 0, chararr_count);
}
}