io.undertow.websockets.core.UTF8Output Maven / Gradle / Ivy
/*
* 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.websockets.core;
import org.xnio.Buffers;
import java.nio.ByteBuffer;
/**
* Utility class which allows to extract a UTF8 String from bytes respecting valid code-points
*/
public final class UTF8Output {
private static final int UTF8_ACCEPT = 0;
private static final byte HIGH_BIT = (byte) (1 << 7);
private static final byte[] TYPES = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8,
8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 10, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, 11, 6, 6, 6, 5, 8, 8, 8, 8, 8,
8, 8, 8, 8, 8, 8};
private static final byte[] STATES = {0, 12, 24, 36, 60, 96, 84, 12, 12, 12, 48, 72, 12, 12,
12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 0, 12, 12, 12, 12, 12, 0, 12, 0, 12, 12,
12, 24, 12, 12, 12, 12, 12, 24, 12, 24, 12, 12, 12, 12, 12, 12, 12, 12, 12, 24, 12, 12,
12, 12, 12, 24, 12, 12, 12, 12, 12, 12, 12, 24, 12, 12, 12, 12, 12, 12, 12, 12, 12, 36,
12, 36, 12, 12, 12, 36, 12, 12, 12, 12, 12, 36, 12, 36, 12, 12, 12, 36, 12, 12, 12, 12,
12, 12, 12, 12, 12, 12};
@SuppressWarnings("RedundantFieldInitialization")
private byte state = UTF8_ACCEPT;
private int codep;
private final StringBuilder stringBuilder;
public UTF8Output(ByteBuffer... payload) {
stringBuilder = new StringBuilder((int) Buffers.remaining(payload));
write(payload);
}
public UTF8Output() {
stringBuilder = new StringBuilder();
}
public void write(ByteBuffer... bytes) {
for (ByteBuffer buf : bytes) {
while (buf.hasRemaining()) {
write(buf.get());
}
}
}
private void write(byte b) {
if(state == UTF8_ACCEPT && (b & HIGH_BIT) == 0) {
stringBuilder.append((char)b);
return;
}
byte type = TYPES[b & 0xFF];
codep = state != UTF8_ACCEPT ? b & 0x3f | codep << 6 : 0xff >> type & b;
state = STATES[state + type];
if (state == UTF8_ACCEPT) {
for (char c : Character.toChars(codep)) {
stringBuilder.append(c);
}
}
}
/**
* Extract a String holding the utf8 text
*/
public String extract() {
String text = stringBuilder.toString();
stringBuilder.setLength(0);
return text;
}
public boolean hasData() {
return stringBuilder.length() != 0;
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy