1 //
2 // ========================================================================
3 // Copyright (c) 1995-2016 Mort Bay Consulting Pty. Ltd.
4 // ------------------------------------------------------------------------
5 // All rights reserved. This program and the accompanying materials
6 // are made available under the terms of the Eclipse Public License v1.0
7 // and Apache License v2.0 which accompanies this distribution.
8 //
9 // The Eclipse Public License is available at
10 // http://www.eclipse.org/legal/epl-v10.html
11 //
12 // The Apache License v2.0 is available at
13 // http://www.opensource.org/licenses/apache2.0.php
14 //
15 // You may elect to redistribute this code under either of these licenses.
16 // ========================================================================
17 //
18
19 package org.eclipse.jetty.websocket.common.util;
20
21 import java.nio.ByteBuffer;
22
23 import org.eclipse.jetty.util.Utf8Appendable;
24 import org.eclipse.jetty.util.Utf8StringBuilder;
25
26 /**
27 * Similar in scope to the {@link Utf8StringBuilder}, but allowing partially constructed Strings without throwing
28 * Exceptions for incomplete UTF8 sequences.
29 * <p>
30 * A call to {@link #toPartialString(ByteBuffer)} will return the section of the String from the start to the last
31 * completed UTF8 sequence. Leaving incomplete sequences for a subsequent call to complete.
32 */
33 public class Utf8PartialBuilder
34 {
35 private final StringBuilder str;
36 private final Utf8Appendable utf8;
37
38 public Utf8PartialBuilder()
39 {
40 this.str = new StringBuilder();
41 this.utf8 = new Utf8Appendable(str)
42 {
43 @Override
44 public int length()
45 {
46 return str.length();
47 }
48 };
49 }
50
51 public String toPartialString(ByteBuffer buf)
52 {
53 if (buf == null)
54 {
55 // no change, return empty
56 return "";
57 }
58 utf8.append(buf);
59 String ret = str.toString();
60 str.setLength(0);
61 return ret;
62 }
63 }