JAL-3026 srcjar files for VARNA and log4j

[jalview.git] / srcjar / org / apache / log4j / pattern / ThrowableInformationPatternConverter.java

diff --git a/srcjar/org/apache/log4j/pattern/ThrowableInformationPatternConverter.java b/srcjar/org/apache/log4j/pattern/ThrowableInformationPatternConverter.java
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+++ b/srcjar/org/apache/log4j/pattern/ThrowableInformationPatternConverter.java
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+/*
+ * 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.log4j.pattern;
+
+import org.apache.log4j.spi.LoggingEvent;
+import org.apache.log4j.spi.ThrowableInformation;
+
+
+/**
+ * Outputs the ThrowableInformation portion of the LoggingEvent.
+ * By default, outputs the full stack trace.  %throwable{none}
+ * or %throwable{0} suppresses the stack trace. %throwable{short}
+ * or %throwable{1} outputs just the first line.  %throwable{n}
+ * will output n lines for a positive integer or drop the last
+ * -n lines for a negative integer.
+ *
+ * @author Paul Smith
+ *
+ */
+public class ThrowableInformationPatternConverter
+  extends LoggingEventPatternConverter {
+
+  /**
+   * Maximum lines of stack trace to output.
+   */
+  private int maxLines = Integer.MAX_VALUE;
+
+  /**
+   * Private constructor.
+   * @param options options, may be null.
+   */
+  private ThrowableInformationPatternConverter(
+    final String[] options) {
+    super("Throwable", "throwable");
+
+    if ((options != null) && (options.length > 0)) {
+      if("none".equals(options[0])) {
+          maxLines = 0;
+      } else if("short".equals(options[0])) {
+          maxLines = 1;
+      } else {
+          try {
+              maxLines = Integer.parseInt(options[0]);
+          } catch(NumberFormatException ex) {
+          }
+      }
+    }
+  }
+
+  /**
+   * Gets an instance of the class.
+    * @param options pattern options, may be null.  If first element is "short",
+   * only the first line of the throwable will be formatted.
+   * @return instance of class.
+   */
+  public static ThrowableInformationPatternConverter newInstance(
+    final String[] options) {
+    return new ThrowableInformationPatternConverter(options);
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  public void format(final LoggingEvent event, final StringBuffer toAppendTo) {
+    if (maxLines != 0) {
+      ThrowableInformation information = event.getThrowableInformation();
+
+      if (information != null) {
+        String[] stringRep = information.getThrowableStrRep();
+
+        int length = stringRep.length;
+        if (maxLines < 0) {
+            length += maxLines;
+        } else if (length > maxLines) {
+            length = maxLines;
+        }
+
+        for (int i = 0; i < length; i++) {
+            String string = stringRep[i];
+            toAppendTo.append(string).append("\n");
+        }
+      }
+    }
+  }
+
+  /**
+   * This converter obviously handles throwables.
+   * @return true.
+   */
+  public boolean handlesThrowable() {
+    return true;
+  }
+}