KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > eclipse > jdi > internal > jdwp > JdwpString


1 /*******************************************************************************
2  * Copyright (c) 2000, 2005 IBM Corporation and others.
3  * All rights reserved. This program and the accompanying materials
4  * are made available under the terms of the Eclipse Public License v1.0
5  * which accompanies this distribution, and is available at
6  * http://www.eclipse.org/legal/epl-v10.html
7  *
8  * Contributors:
9  * IBM Corporation - initial API and implementation
10  *******************************************************************************/
11 package org.eclipse.jdi.internal.jdwp;
12
13  
14 import java.io.DataInputStream JavaDoc;
15 import java.io.DataOutputStream JavaDoc;
16 import java.io.IOException JavaDoc;
17 import java.io.UTFDataFormatException JavaDoc;
18
19 /**
20  * This class implements the corresponding Java Debug Wire Protocol (JDWP) ID
21  * declared by the JDWP specification.
22  *
23  */
24 public class JdwpString {
25     /**
26      * Reads String from Jdwp stream.
27      * Read a UTF where length has 4 bytes, and not just 2.
28      * This code was based on the OTI Retysin source for readUTF.
29      */
30     public static String JavaDoc read(DataInputStream JavaDoc in) throws IOException JavaDoc {
31         int utfSize = in.readInt();
32         byte utfBytes[] = new byte[utfSize];
33         in.readFully(utfBytes);
34         /* Guess at buffer size */
35         StringBuffer JavaDoc strBuffer = new StringBuffer JavaDoc(utfSize / 3 * 2);
36         for (int i = 0; i < utfSize;) {
37             int a = utfBytes[i] & 0xFF;
38             if ((a >> 4) < 12) {
39                 strBuffer.append((char) a);
40                 i++;
41             } else {
42                 int b = utfBytes[i + 1] & 0xFF;
43                 if ((a >> 4) < 14) {
44                     if ((b & 0xBF) == 0) {
45                         throw new UTFDataFormatException JavaDoc(JDWPMessages.JdwpString_Second_byte_input_does_not_match_UTF_Specification_1);
46                     }
47                     strBuffer.append((char) (((a & 0x1F) << 6) | (b & 0x3F)));
48                     i += 2;
49                 } else {
50                     int c = utfBytes[i + 2] & 0xFF;
51                     if ((a & 0xEF) > 0) {
52                         if (((b & 0xBF) == 0) || ((c & 0xBF) == 0)) {
53                             throw new UTFDataFormatException JavaDoc(JDWPMessages.JdwpString_Second_or_third_byte_input_does_not_mach_UTF_Specification_2);
54                         }
55                         strBuffer.append((char) (((a & 0x0F) << 12) | ((b & 0x3F) << 6) | (c & 0x3F)));
56                         i += 3;
57                     } else {
58                         throw new UTFDataFormatException JavaDoc(JDWPMessages.JdwpString_Input_does_not_match_UTF_Specification_3);
59                     }
60                 }
61             }
62         }
63         return strBuffer.toString();
64     }
65
66  
67     /**
68      * Writes String to Jdwp stream.
69      * Write a UTF where length has 4 bytes, and not just 2.
70      * This code was based on OTI Retsin source for writeUTF.
71      */
72     public static void write(String JavaDoc str, DataOutputStream JavaDoc out) throws IOException JavaDoc {
73         if (str == null)
74             throw new NullPointerException JavaDoc(JDWPMessages.JdwpString_str_is_null_4);
75         int utfCount = 0;
76         for (int i = 0; i < str.length(); i++) {
77             int charValue = str.charAt(i);
78             if (charValue > 0 && charValue <= 127)
79                 utfCount += 1;
80             else
81                 if (charValue <= 2047)
82                     utfCount += 2;
83                 else
84                     utfCount += 3;
85         }
86         byte utfBytes[] = new byte[utfCount];
87         int utfIndex = 0;
88         for (int i = 0; i < str.length(); i++) {
89             int charValue = str.charAt(i);
90             if (charValue > 0 && charValue <= 127)
91                 utfBytes[utfIndex++] = (byte) charValue;
92             else
93                 if (charValue <= 2047) {
94                     utfBytes[utfIndex++] = (byte) (0xc0 | (0x1f & (charValue >> 6)));
95                     utfBytes[utfIndex++] = (byte) (0x80 | (0x3f & charValue));
96                 } else {
97                     utfBytes[utfIndex++] = (byte) (0xe0 | (0x0f & (charValue >> 12)));
98                     utfBytes[utfIndex++] = (byte) (0x80 | (0x3f & (charValue >> 6)));
99                     utfBytes[utfIndex++] = (byte) (0x80 | (0x3f & charValue));
100                 }
101         }
102         out.writeInt(utfCount);
103         if (utfCount > 0)
104             out.write(utfBytes);
105     }
106 }
107
Popular Tags