1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.log4j;
18
19 import org.apache.log4j.spi.ThrowableRenderer;
20
21 import java.io.StringWriter;
22 import java.io.PrintWriter;
23 import java.io.LineNumberReader;
24 import java.io.StringReader;
25 import java.io.IOException;
26 import java.io.InterruptedIOException;
27 import java.util.ArrayList;
28
29 /**
30 * Default implementation of ThrowableRenderer using
31 * Throwable.printStackTrace.
32 *
33 * @since 1.2.16
34 */
35 public final class DefaultThrowableRenderer implements ThrowableRenderer {
36 /**
37 * Construct new instance.
38 */
39 public DefaultThrowableRenderer() {
40
41 }
42
43
44 /**
45 * {@inheritDoc}
46 */
47 public String[] doRender(final Throwable throwable) {
48 return render(throwable);
49 }
50
51 /**
52 * Render throwable using Throwable.printStackTrace.
53 * @param throwable throwable, may not be null.
54 * @return string representation.
55 */
56 public static String[] render(final Throwable throwable) {
57 StringWriter sw = new StringWriter();
58 PrintWriter pw = new PrintWriter(sw);
59 try {
60 throwable.printStackTrace(pw);
61 } catch(RuntimeException ex) {
62 }
63 pw.flush();
64 LineNumberReader reader = new LineNumberReader(
65 new StringReader(sw.toString()));
66 ArrayList lines = new ArrayList();
67 try {
68 String line = reader.readLine();
69 while(line != null) {
70 lines.add(line);
71 line = reader.readLine();
72 }
73 } catch(IOException ex) {
74 if (ex instanceof InterruptedIOException) {
75 Thread.currentThread().interrupt();
76 }
77 lines.add(ex.toString());
78 }
79 String[] tempRep = new String[lines.size()];
80 lines.toArray(tempRep);
81 return tempRep;
82 }
83 }