ServletPrintWriter.java
/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed 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 io.undertow.servlet.spec;
import jakarta.servlet.DispatcherType;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.UnsupportedCharsetException;
import java.util.Locale;
/**
* Real servlet print writer functionality, that is not limited by extending
* {@link java.io.PrintWriter}
* <p>
*
* @author Stuart Douglas
*/
public class ServletPrintWriter {
private static final char[] EMPTY_CHAR = {};
private final ServletOutputStreamImpl outputStream;
private final String charset;
private CharsetEncoder charsetEncoder;
private boolean error = false;
private boolean closed = false;
private char[] underflow;
public ServletPrintWriter(final ServletOutputStreamImpl outputStream, final String charset) throws UnsupportedEncodingException {
this.charset = charset;
this.outputStream = outputStream;
//for some known charset we get optimistic and hope that
//only ascii will be output
//in this case we can avoid creating the encoder altogether
if (!charset.equalsIgnoreCase("utf-8") &&
!charset.equalsIgnoreCase("iso-8859-1")) {
createEncoder();
}
}
private void createEncoder() throws UnsupportedEncodingException {
try {
this.charsetEncoder = Charset.forName(this.charset).newEncoder();
//replace malformed and unmappable with question marks
this.charsetEncoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
this.charsetEncoder.onMalformedInput(CodingErrorAction.REPLACE);
} catch (UnsupportedCharsetException e) {
// Servlet 6 clarification - UnsupportedEncodingException must be thrown
final UnsupportedEncodingException uee = new UnsupportedEncodingException(e.getMessage());
uee.initCause(e);
throw uee;
}
}
public void flush() {
try {
outputStream.flush();
} catch (IOException e) {
error = true;
}
}
public void close() {
if (outputStream.getServletRequestContext().getOriginalRequest().getDispatcherType() == DispatcherType.INCLUDE) {
return;
}
if (closed) {
return;
}
closed = true;
try {
boolean done = false;
CharBuffer buffer;
if (underflow == null) {
buffer = CharBuffer.wrap(EMPTY_CHAR);
} else {
buffer = CharBuffer.wrap(underflow);
underflow = null;
}
if (charsetEncoder != null) {
int remaining = 0;
do {
// before we get the underlying buffer, we need to flush outputStream
ByteBuffer out = outputStream.underlyingBuffer();
if (out == null) {
//servlet output stream has already been closed
error = true;
return;
}
CoderResult result = charsetEncoder.encode(buffer, out, true);
if (result.isOverflow()) {
outputStream.flushInternal();
if (out.remaining() == remaining) {
// no progress in flush
outputStream.close();
error = true;
return;
} else
remaining = out.remaining();
} else {
done = true;
}
} while (!done);
}
outputStream.close();
} catch (IOException e) {
error = true;
}
}
public boolean checkError() {
flush();
return error;
}
public void write(final CharBuffer input) {
ByteBuffer buffer = outputStream.underlyingBuffer();
if (buffer == null) {
//stream has been closed
error = true;
return;
}
try {
if (!buffer.hasRemaining()) {
outputStream.flushInternal();
if (!buffer.hasRemaining()) {
error = true;
return;
}
}
if (charsetEncoder == null) {
createEncoder();
}
final CharBuffer cb;
if (underflow == null) {
cb = input;
} else {
char[] newArray = new char[underflow.length + input.remaining()];
System.arraycopy(underflow, 0, newArray, 0, underflow.length);
input.get(newArray, underflow.length, input.remaining());
cb = CharBuffer.wrap(newArray);
underflow = null;
}
int last = -1;
long remainingContentLength = outputStream.remainingContentLength();
while (remainingContentLength > 0 && cb.hasRemaining()) {
final int remaining = buffer.remaining();
final CoderResult result = charsetEncoder.encode(cb, buffer, false);
long writtenLength = remaining - buffer.remaining();
if (remainingContentLength < writtenLength) {
buffer.position(buffer.position() - (int) (writtenLength - remainingContentLength));
writtenLength = remainingContentLength;
}
remainingContentLength -= writtenLength;
outputStream.updateWritten(writtenLength);
if (result.isOverflow() || !buffer.hasRemaining()) {
final int remainingBytesBeforeFlush = buffer.remaining();
outputStream.flushInternal();
if (buffer.remaining() == remainingBytesBeforeFlush) {
// no progress has been made, set error to true
error = true;
return;
}
}
if (result.isUnderflow()) {
underflow = new char[cb.remaining()];
cb.get(underflow);
return;
}
if (result.isError()) {
error = true;
return;
}
if (result.isUnmappable()) {
//this should not happen
error = true;
return;
}
if (last == cb.remaining()) {
underflow = new char[cb.remaining()];
cb.get(underflow);
return;
}
last = cb.remaining();
}
} catch (IOException e) {
error = true;
}
}
public void write(final int c) {
write(Character.toString((char) c));
}
public void write(final char[] buf, final int off, final int len) {
if (charsetEncoder == null) {
try {
ByteBuffer buffer = outputStream.underlyingBuffer();
if (buffer == null) {
//already closed
error = true;
return;
}
//fast path, basically we are hoping this is ascii only
int remaining = buffer.remaining();
int end = off + len;
//so we have a pure ascii buffer, just write it out and skip all the encoder cost
final int sPos = writeAndFlushAscii(outputStream, buffer, buf, off, off + len);
outputStream.updateWritten(remaining - buffer.remaining());
if (sPos == end) {
return;
}
final CharBuffer cb = CharBuffer.wrap(buf, sPos, len - (sPos - off));
write(cb);
return;
} catch (IOException e) {
error = false;
return;
}
}
final CharBuffer cb = CharBuffer.wrap(buf, off, len);
write(cb);
}
private static int writeAndFlushAscii(ServletOutputStreamImpl outputStream, ByteBuffer buffer, char[] chars, int start, int end) throws IOException {
assert buffer.order() == ByteOrder.BIG_ENDIAN;
int i = start;
long remainingContentLength = outputStream.remainingContentLength();
while (i < end) {
final int bufferPos = buffer.position();
final int bufferRemaining = buffer.remaining();
final int sRemaining = end - i;
final int remaining = Math.min(sRemaining, bufferRemaining);
final int written = setAsciiBE(buffer, bufferPos, chars, i, remaining);
i += written;
if ((remainingContentLength -= written) < 0) {
buffer.position(bufferPos + written + (int) remainingContentLength);
} else {
buffer.position(bufferPos + written);
}
if (!buffer.hasRemaining()) {
outputStream.flushInternal();
}
// we have given up with the fast path? slow path NOW!
if (written < remaining) {
return i;
}
}
return i;
}
private static int setAsciiBE(ByteBuffer buffer, int out, char[] chars, int off, int len) {
final int longRounds = len >>> 3;
for (int i = 0; i < longRounds; i++) {
final long batch1 = (((long) chars[off]) << 48) |
(((long) chars[off + 2]) << 32) |
chars[off + 4] << 16 |
chars[off + 6];
final long batch2 = (((long) chars[off + 1]) << 48) |
(((long) chars[off + 3]) << 32) |
chars[off + 5] << 16 |
chars[off + 7];
if (((batch1 | batch2) & 0xff80_ff80_ff80_ff80L) != 0) {
return i << 3;
}
final long batch = (batch1 << 8) | batch2;
buffer.putLong(out, batch);
out += Long.BYTES;
off += Long.BYTES;
}
final int byteRounds = len & 7;
if (byteRounds > 0) {
for (int i = 0; i < byteRounds; i++) {
final char c = chars[off + i];
if (c > 127) {
return (longRounds << 3) + i;
}
buffer.put(out + i, (byte) c);
}
}
return len;
}
public void write(final char[] buf) {
write(buf, 0, buf.length);
}
public void write(final String s, final int off, final int len) {
if (charsetEncoder == null) {
try {
ByteBuffer buffer = outputStream.underlyingBuffer();
if (buffer == null) {
//already closed
error = true;
return;
}
//fast path, basically we are hoping this is ascii only
int remaining = buffer.remaining();
int end = off + len;
//so we have a pure ascii buffer, just write it out and skip all the encoder cost
final int sPos = writeAndFlushAscii(outputStream, buffer, s, off, off + len);
outputStream.updateWritten(remaining - buffer.remaining());
if (sPos == end) {
return;
}
//wrap(String, off, len) acts wrong in the presence of multi byte characters
final CharBuffer cb = CharBuffer.wrap(s.toCharArray(), sPos, len - (sPos - off));
write(cb);
return;
} catch (IOException e) {
error = false;
return;
}
}
final CharBuffer cb = CharBuffer.wrap(s, off, off + len);
write(cb);
}
private static int writeAndFlushAscii(ServletOutputStreamImpl outputStream, ByteBuffer buffer, String s, int start, int end) throws IOException {
assert buffer.order() == ByteOrder.BIG_ENDIAN;
int i = start;
long remainingContentLength = outputStream.remainingContentLength();
while (i < end) {
final int bufferPos = buffer.position();
final int bufferRemaining = buffer.remaining();
final int sRemaining = end - i;
final int remaining = Math.min(sRemaining, bufferRemaining);
final int written = setAsciiBE(buffer, bufferPos, s, i, remaining);
i += written;
if ((remainingContentLength -= written) < 0) {
buffer.position(bufferPos + written + (int) remainingContentLength);
} else {
buffer.position(bufferPos + written);
}
if (!buffer.hasRemaining()) {
outputStream.flushInternal();
}
// we have given up with the fast path? slow path NOW!
if (written < remaining) {
return i;
}
}
return i;
}
private static int setAsciiBE(ByteBuffer buffer, int out, String s, int off, int len) {
final int longRounds = len >>> 3;
for (int i = 0; i < longRounds; i++) {
final long batch1 = ((long)s.charAt(off)) << 48 |
((long) s.charAt(off + 2)) << 32 |
s.charAt(off + 4) << 16 |
s.charAt(off + 6);
final long batch2 = ((long)s.charAt(off + 1)) << 48 |
((long) s.charAt(off + 3)) << 32 |
s.charAt(off + 5) << 16 |
s.charAt(off + 7);
if (((batch1 | batch2) & 0xff80_ff80_ff80_ff80L) != 0) {
return i << 3;
}
final long batch = (batch1 << 8) | batch2;
buffer.putLong(out, batch);
out += Long.BYTES;
off += Long.BYTES;
}
final int byteRounds = len & 7;
if (byteRounds > 0) {
for (int i = 0; i < byteRounds; i++) {
final char c = s.charAt(off + i);
if (c > 127) {
return (longRounds << 3) + i;
}
buffer.put(out + i, (byte) c);
}
}
return len;
}
public void write(final String s) {
write(s, 0, s.length());
}
public void print(final boolean b) {
write(Boolean.toString(b));
}
public void print(final char c) {
write(Character.toString(c));
}
public void print(final int i) {
write(Integer.toString(i));
}
public void print(final long l) {
write(Long.toString(l));
}
public void print(final float f) {
write(Float.toString(f));
}
public void print(final double d) {
write(Double.toString(d));
}
public void print(final char[] s) {
write(CharBuffer.wrap(s));
}
public void print(final String s) {
write(s == null ? "null" : s);
}
public void print(final Object obj) {
write(obj == null ? "null" : obj.toString());
}
public void println() {
print("\r\n");
}
public void println(final boolean b) {
print(b);
println();
}
public void println(final char c) {
print(c);
println();
}
public void println(final int i) {
print(i);
println();
}
public void println(final long l) {
print(l);
println();
}
public void println(final float f) {
print(f);
println();
}
public void println(final double d) {
print(d);
println();
}
public void println(final char[] s) {
print(s);
println();
}
public void println(final String s) {
print(s);
println();
}
public void println(final Object obj) {
print(obj);
println();
}
public void printf(final String format, final Object... args) {
print(String.format(format, args));
}
public void printf(final Locale l, final String format, final Object... args) {
print(String.format(l, format, args));
}
public void format(final String format, final Object... args) {
printf(format, args);
}
public void format(final Locale l, final String format, final Object... args) {
printf(l, format, args);
}
public void append(final CharSequence csq) {
if (csq == null) {
write("null");
} else {
write(csq.toString());
}
}
public void append(final CharSequence csq, final int start, final int end) {
CharSequence cs = (csq == null ? "null" : csq);
write(cs.subSequence(start, end).toString());
}
public void append(final char c) {
write(c);
}
}