1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
/*
* Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package p;
import java.io.File;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import java.util.jar.Attributes;
import java.util.jar.JarEntry;
import java.util.jar.JarFile;
import java.util.jar.JarOutputStream;
import java.util.jar.Manifest;
import com.sun.tools.attach.VirtualMachine;
public class Main {
public static void main(String[] args) throws Exception {
System.out.println("#modules loaded: " + moduleInfoCont());
String vmid = "" + ProcessHandle.current().pid();
VirtualMachine vm = VirtualMachine.attach(vmid);
for (String test : args) {
switch (test) {
case "jmx" :
startJMXAgent(vm);
break;
case "javaagent" :
startJavaAgent(vm, createAgentJar());
break;
}
System.out.println("#modules loaded: " + moduleInfoCont());
}
}
/**
* Locates module-info.class resources to get a count of the module of system
* modules.
*/
static long moduleInfoCont() {
ClassLoader scl = ClassLoader.getSystemClassLoader();
return scl.resources("module-info.class").count();
}
/**
* Starts a JMX agent and checks that java.management is loaded.
*/
static void startJMXAgent(VirtualMachine vm) throws Exception {
System.out.println("Start JMX agent");
vm.startLocalManagementAgent();
// types in java.management should be visible
Class.forName("javax.management.MXBean");
}
/**
* Loads a java agent into the VM and checks that java.instrument is loaded.
*/
static void startJavaAgent(VirtualMachine vm, Path agent) throws Exception {
System.out.println("Load java agent ...");
vm.loadAgent(agent.toString());
// the Agent class should be visible
Class.forName("Agent");
// types in java.instrument should be visible
Class.forName("java.lang.instrument.Instrumentation");
}
/**
* Creates a java agent, return the file path to the agent JAR file.
*/
static Path createAgentJar() throws IOException {
Manifest man = new Manifest();
Attributes attrs = man.getMainAttributes();
attrs.put(Attributes.Name.MANIFEST_VERSION, "1.0.0");
attrs.put(new Attributes.Name("Agent-Class"), "Agent");
Path agent = Paths.get("agent.jar");
Path dir = Paths.get(System.getProperty("test.classes"));
createJarFile(agent, man, dir, "Agent.class");
return agent;
}
/**
* Creates a JAR file.
*
* Equivalent to {@code jar cfm <jarfile> <manifest> -C <dir> file...}
*
* The input files are resolved against the given directory. Any input
* files that are directories are processed recursively.
*/
static void createJarFile(Path jarfile, Manifest man, Path dir, String... files)
throws IOException
{
// create the target directory
Path parent = jarfile.getParent();
if (parent != null)
Files.createDirectories(parent);
List<Path> entries = new ArrayList<>();
for (String file : files) {
Files.find(dir.resolve(file), Integer.MAX_VALUE,
(p, attrs) -> attrs.isRegularFile())
.map(e -> dir.relativize(e))
.forEach(entries::add);
}
try (OutputStream out = Files.newOutputStream(jarfile);
JarOutputStream jos = new JarOutputStream(out))
{
if (man != null) {
JarEntry je = new JarEntry(JarFile.MANIFEST_NAME);
jos.putNextEntry(je);
man.write(jos);
jos.closeEntry();
}
for (Path entry : entries) {
String name = toJarEntryName(entry);
jos.putNextEntry(new JarEntry(name));
Files.copy(dir.resolve(entry), jos);
jos.closeEntry();
}
}
}
/**
* Map a file path to the equivalent name in a JAR file
*/
static String toJarEntryName(Path file) {
Path normalized = file.normalize();
return normalized.subpath(0, normalized.getNameCount())
.toString()
.replace(File.separatorChar, '/');
}
}
|
