-
Notifications
You must be signed in to change notification settings - Fork 290
/
SecurityManagerCallStack.java
124 lines (113 loc) · 4.17 KB
/
SecurityManagerCallStack.java
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
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.pool2.impl;
import java.io.PrintWriter;
import java.lang.ref.WeakReference;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
/**
* CallStack strategy using a {@link SecurityManager}. Obtaining the current call stack is much faster via a
* SecurityManger, but access to the underlying method may be restricted by the current SecurityManager. In environments
* where a SecurityManager cannot be created, {@link ThrowableCallStack} should be used instead.
*
* @see RuntimePermission
* @see SecurityManager#getClassContext()
* @since 2.4.3
*/
public class SecurityManagerCallStack implements CallStack {
private final String messageFormat;
//@GuardedBy("dateFormat")
private final DateFormat dateFormat;
private final PrivateSecurityManager securityManager;
private volatile Snapshot snapshot;
/**
* Create a new instance.
*
* @param messageFormat message format
* @param useTimestamp whether to format the dates in the output message or not
*/
public SecurityManagerCallStack(final String messageFormat, final boolean useTimestamp) {
this.messageFormat = messageFormat;
this.dateFormat = useTimestamp ? new SimpleDateFormat(messageFormat) : null;
this.securityManager = AccessController.doPrivileged((PrivilegedAction<PrivateSecurityManager>) PrivateSecurityManager::new);
}
@Override
public boolean printStackTrace(final PrintWriter writer) {
final Snapshot snapshotRef = this.snapshot;
if (snapshotRef == null) {
return false;
}
final String message;
if (dateFormat == null) {
message = messageFormat;
} else {
synchronized (dateFormat) {
message = dateFormat.format(Long.valueOf(snapshotRef.timestampMillis));
}
}
writer.println(message);
for (final WeakReference<Class<?>> reference : snapshotRef.stack) {
writer.println(reference.get());
}
return true;
}
@Override
public void fillInStackTrace() {
snapshot = new Snapshot(securityManager.getCallStack());
}
@Override
public void clear() {
snapshot = null;
}
/**
* A custom security manager.
*/
private static class PrivateSecurityManager extends SecurityManager {
/**
* Get the class stack.
*
* @return class stack
*/
private List<WeakReference<Class<?>>> getCallStack() {
final Class<?>[] classes = getClassContext();
final List<WeakReference<Class<?>>> stack = new ArrayList<>(classes.length);
for (final Class<?> klass : classes) {
stack.add(new WeakReference<Class<?>>(klass));
}
return stack;
}
}
/**
* A snapshot of a class stack.
*/
private static class Snapshot {
private final long timestampMillis = System.currentTimeMillis();
private final List<WeakReference<Class<?>>> stack;
/**
* Create a new snapshot with a class stack.
*
* @param stack class stack
*/
private Snapshot(final List<WeakReference<Class<?>>> stack) {
this.stack = stack;
}
}
}