1 /*
2  * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.
3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4  *
5  * This code is free software; you can redistribute it and/or modify it
6  * under the terms of the GNU General Public License version 2 only, as
7  * published by the Free Software Foundation.
8  *
9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
16  * 2 along with this work; if not, write to the Free Software Foundation,
17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18  *
19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20  * or visit www.oracle.com if you need additional information or have any
21  * questions.
22  */
23 
24 import java.io.ByteArrayInputStream;
25 import java.io.DataInputStream;
26 import java.io.IOException;
27 import java.io.InputStream;
28 
29 /**
30  * Generic JDWP reply
31  */
32 public abstract class JdwpReply {
33 
34     protected final static int HEADER_LEN = 11;
35     private byte[] errCode = new byte[2];
36     private byte[] data;
37 
initFromStream(InputStream is)38     public final void initFromStream(InputStream is) throws IOException {
39         DataInputStream ds = new DataInputStream(is);
40 
41         int length = ds.readInt();
42         int id = ds.readInt();
43         byte flags = (byte) ds.read();
44 
45         ds.read(errCode, 0, 2);
46 
47         int dataLength = length - HEADER_LEN;
48         if (dataLength > 0) {
49             data = new byte[dataLength];
50             int bytesRead = ds.read(data, 0, dataLength);
51             // For large data JDWP agent sends two packets: 1011 bytes in
52             // the first packet (1000 + HEADER_LEN) and the rest in the
53             // second packet.
54             if (bytesRead > 0 && bytesRead < dataLength) {
55                 System.out.println("[" + getClass().getName() + "] Only " +
56                         bytesRead + " bytes of " + dataLength + " were " +
57                         "read in the first packet. Reading the rest...");
58                 ds.read(data, bytesRead, dataLength - bytesRead);
59             }
60 
61             parseData(new DataInputStream(new ByteArrayInputStream(data)));
62         }
63     }
64 
parseData(DataInputStream ds)65     protected void parseData(DataInputStream ds) throws IOException {
66     }
67 
readJdwpString(DataInputStream ds)68     protected byte[] readJdwpString(DataInputStream ds) throws IOException {
69         byte[] str = null;
70         int len = ds.readInt();
71         if (len > 0) {
72             str = new byte[len];
73             ds.read(str, 0, len);
74         }
75         return str;
76     }
77 
readRefId(DataInputStream ds)78     protected long readRefId(DataInputStream ds) throws IOException {
79         return ds.readLong();
80     }
81 
getErrorCode()82     public int getErrorCode() {
83         return (((errCode[0] & 0xFF) << 8) | (errCode[1] & 0xFF));
84     }
85 }
86