1 /*
2 * Copyright 2012-2025 CodeLibs Project and the Others.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
13 * either express or implied. See the License for the specific language
14 * governing permissions and limitations under the License.
15 */
16 package org.codelibs.fess.util;
17
18 import java.io.BufferedWriter;
19 import java.io.FileOutputStream;
20 import java.io.IOException;
21 import java.io.OutputStreamWriter;
22 import java.io.Writer;
23 import java.util.Map;
24 import java.util.function.Consumer;
25
26 import org.apache.logging.log4j.LogManager;
27 import org.apache.logging.log4j.Logger;
28 import org.codelibs.core.exception.IORuntimeException;
29 import org.codelibs.fess.Constants;
30
31 /**
32 * Utility class for generating and writing thread dumps.
33 * Provides methods to capture thread information for debugging purposes.
34 */
35 public class ThreadDumpUtil {
36 private static final Logger logger = LogManager.getLogger(ThreadDumpUtil.class);
37
38 /**
39 * Private constructor to prevent instantiation of this utility class.
40 */
41 protected ThreadDumpUtil() {
42 // noop
43 }
44
45 /**
46 * Prints thread dump information to the logger at INFO level.
47 */
48 public static void printThreadDump() {
49 processThreadDump(logger::info);
50 }
51
52 /**
53 * Prints thread dump information to the logger at WARN level.
54 */
55 public static void printThreadDumpAsWarn() {
56 processThreadDump(logger::warn);
57 }
58
59 /**
60 * Prints thread dump information to the logger at ERROR level.
61 */
62 public static void printThreadDumpAsError() {
63 processThreadDump(logger::error);
64 }
65
66 /**
67 * Writes thread dump information to the specified file.
68 *
69 * @param file the file path to write the thread dump to
70 */
71 public static void writeThreadDump(final String file) {
72 try (final Writer writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), Constants.CHARSET_UTF_8))) {
73 processThreadDump(s -> {
74 try {
75 writer.write(s);
76 writer.write('\n');
77 } catch (final IOException e) {
78 throw new IORuntimeException(e);
79 }
80 });
81 } catch (final Exception e) {
82 logger.warn("Failed to write thread dump: file={}", file, e);
83 }
84 }
85
86 /**
87 * Processes all thread information and sends it to the provided consumer.
88 *
89 * @param writer the consumer that will handle each line of thread dump output
90 */
91 public static void processThreadDump(final Consumer<String> writer) {
92 for (final Map.Entry<Thread, StackTraceElement[]> entry : Thread.getAllStackTraces().entrySet()) {
93 writer.accept("Thread: " + entry.getKey());
94 final StackTraceElement[] trace = entry.getValue();
95 for (final StackTraceElement element : trace) {
96 writer.accept("\tat " + element);
97 }
98 }
99 }
100 }