1/*
2 * Copyright (c) 2005, 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.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25package jdk.internal.vm;
26
27import java.io.ByteArrayOutputStream;
28import java.io.IOException;
29import java.util.Properties;
30import java.util.Set;
31import java.util.jar.JarFile;
32import java.util.jar.Manifest;
33import java.util.jar.Attributes;
34
35/*
36 * Support class used by JVMTI and VM attach mechanism.
37 */
38public class VMSupport {
39
40    private static Properties agentProps = null;
41    /**
42     * Returns the agent properties.
43     */
44    public static synchronized Properties getAgentProperties() {
45        if (agentProps == null) {
46            agentProps = new Properties();
47            initAgentProperties(agentProps);
48        }
49        return agentProps;
50    }
51    private static native Properties initAgentProperties(Properties props);
52
53    /**
54     * Write the given properties list to a byte array and return it. Properties with
55     * a key or value that is not a String is filtered out. The stream written to the byte
56     * array is ISO 8859-1 encoded.
57     */
58    private static byte[] serializePropertiesToByteArray(Properties p) throws IOException {
59        ByteArrayOutputStream out = new ByteArrayOutputStream(4096);
60
61        Properties props = new Properties();
62
63        // stringPropertyNames() returns a snapshot of the property keys
64        Set<String> keyset = p.stringPropertyNames();
65        for (String key : keyset) {
66            String value = p.getProperty(key);
67            props.put(key, value);
68        }
69
70        props.store(out, null);
71        return out.toByteArray();
72    }
73
74    public static byte[] serializePropertiesToByteArray() throws IOException {
75        return serializePropertiesToByteArray(System.getProperties());
76    }
77
78    public static byte[] serializeAgentPropertiesToByteArray() throws IOException {
79        return serializePropertiesToByteArray(getAgentProperties());
80    }
81
82    /*
83     * Returns true if the given JAR file has the Class-Path attribute in the
84     * main section of the JAR manifest. Throws RuntimeException if the given
85     * path is not a JAR file or some other error occurs.
86     */
87    public static boolean isClassPathAttributePresent(String path) {
88        try {
89            Manifest man = (new JarFile(path)).getManifest();
90            if (man != null) {
91                if (man.getMainAttributes().getValue(Attributes.Name.CLASS_PATH) != null) {
92                    return true;
93                }
94            }
95            return false;
96        } catch (IOException ioe) {
97            throw new RuntimeException(ioe.getMessage());
98        }
99    }
100
101    /*
102     * Return the temporary directory that the VM uses for the attach
103     * and perf data files.
104     *
105     * It is important that this directory is well-known and the
106     * same for all VM instances. It cannot be affected by configuration
107     * variables such as java.io.tmpdir.
108     */
109    public static native String getVMTemporaryDirectory();
110}
111