Removed @PluginAttribute 'patternFlags' argument from @PluginFactory for RegexFilter. (#3086)

log4j-core/src/main/java/org/apache/logging/log4j/core/filter/RegexFilter.java

@@ -16,9 +16,6 @@
  */
 package org.apache.logging.log4j.core.filter;
 
-import java.lang.reflect.Field;
-import java.util.Arrays;
-import java.util.Comparator;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import org.apache.logging.log4j.Level;
@@ -29,7 +26,6 @@
 import org.apache.logging.log4j.core.config.Node;
 import org.apache.logging.log4j.core.config.plugins.Plugin;
 import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
-import org.apache.logging.log4j.core.config.plugins.PluginElement;
 import org.apache.logging.log4j.core.config.plugins.PluginFactory;
 import org.apache.logging.log4j.message.Message;
 import org.apache.logging.log4j.message.MessageFormatMessage;
@@ -43,7 +39,6 @@
 @Plugin(name = "RegexFilter", category = Node.CATEGORY, elementType = Filter.ELEMENT_TYPE, printObject = true)
 public final class RegexFilter extends AbstractFilter {
 
-    private static final int DEFAULT_PATTERN_FLAGS = 0;
     private final Pattern pattern;
     private final boolean useRawMessage;
 
@@ -110,10 +105,7 @@ private Result filter(final String msg) {
 
     @Override
     public String toString() {
-        final StringBuilder sb = new StringBuilder();
-        sb.append("useRaw=").append(useRawMessage);
-        sb.append(", pattern=").append(pattern.toString());
-        return sb.toString();
+        return "useRaw=" + useRawMessage + ", pattern=" + pattern.toString();
     }
 
     /**
@@ -123,6 +115,40 @@ public String toString() {
      *        The regular expression to match.
      * @param patternFlags
      *        An array of Strings where each String is a {@link Pattern#compile(String, int)} compilation flag.
+     *        (no longer used - pattern flags can be embedded in regex-expression.
+     * @param useRawMsg
+     *        If {@code true}, for {@link ParameterizedMessage}, {@link StringFormattedMessage}, and {@link MessageFormatMessage}, the message format pattern; for {@link StructuredDataMessage}, the message field will be used as the match target.
+     * @param match
+     *        The action to perform when a match occurs.
+     * @param mismatch
+     *        The action to perform when a mismatch occurs.
+     * @return The RegexFilter.
+     * @throws IllegalAccessException  When there is no access to the definition of the specified member.
+     * @throws IllegalArgumentException When passed an illegal or inappropriate argument.
+     * @deprecated use {@link #createFilter(String, Boolean, Result, Result)}
+     */
+    @Deprecated
+    // TODO Consider refactoring to use AbstractFilter.AbstractFilterBuilder
+    public static RegexFilter createFilter(
+            // @formatter:off
+            @PluginAttribute("regex") final String regex,
+            final String[] patternFlags,
+            @PluginAttribute("useRawMsg") final Boolean useRawMsg,
+            @PluginAttribute("onMatch") final Result match,
+            @PluginAttribute("onMismatch") final Result mismatch)
+            // @formatter:on
+            throws IllegalArgumentException, IllegalAccessException {
+
+        // LOG4J-3086 - pattern-flags can be embedded in RegEx expression
+
+        return createFilter(regex, useRawMsg, match, mismatch);
+    }
+
+    /**
+     * Creates a Filter that matches a regular expression.
+     *
+     * @param regex
+     *        The regular expression to match.
      * @param useRawMsg
      *        If {@code true}, for {@link ParameterizedMessage}, {@link StringFormattedMessage}, and {@link MessageFormatMessage}, the message format pattern; for {@link StructuredDataMessage}, the message field will be used as the match target.
      * @param match
@@ -138,40 +164,23 @@ public String toString() {
     public static RegexFilter createFilter(
             // @formatter:off
             @PluginAttribute("regex") final String regex,
-            @PluginElement("PatternFlags") final String[] patternFlags,
             @PluginAttribute("useRawMsg") final Boolean useRawMsg,
             @PluginAttribute("onMatch") final Result match,
             @PluginAttribute("onMismatch") final Result mismatch)
             // @formatter:on
             throws IllegalArgumentException, IllegalAccessException {
+        boolean raw = Boolean.TRUE.equals(useRawMsg);
         if (regex == null) {
             LOGGER.error("A regular expression must be provided for RegexFilter");
             return null;
         }
-        return new RegexFilter(
-                Boolean.TRUE.equals(useRawMsg), Pattern.compile(regex, toPatternFlags(patternFlags)), match, mismatch);
-    }
-
-    private static int toPatternFlags(final String[] patternFlags)
-            throws IllegalArgumentException, IllegalAccessException {
-        if (patternFlags == null || patternFlags.length == 0) {
-            return DEFAULT_PATTERN_FLAGS;
-        }
-        final Field[] fields = Pattern.class.getDeclaredFields();
-        final Comparator<Field> comparator = (f1, f2) -> f1.getName().compareTo(f2.getName());
-        Arrays.sort(fields, comparator);
-        final String[] fieldNames = new String[fields.length];
-        for (int i = 0; i < fields.length; i++) {
-            fieldNames[i] = fields[i].getName();
-        }
-        int flags = DEFAULT_PATTERN_FLAGS;
-        for (final String test : patternFlags) {
-            final int index = Arrays.binarySearch(fieldNames, test);
-            if (index >= 0) {
-                final Field field = fields[index];
-                flags |= field.getInt(Pattern.class);
-            }
+        final Pattern pattern;
+        try {
+            pattern = Pattern.compile(regex);
+        } catch (final Exception ex) {
+            LOGGER.error("Unable to compile regular expression: {}", regex, ex);
+            return null;
         }
-        return flags;
+        return new RegexFilter(raw, pattern, match, mismatch);
     }
 }

src/changelog/2.25.0/3086_change_RegexFilter_remove_patternflags_from_PluginFactory.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<entry xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns="https://logging.apache.org/xml/ns"
+       xsi:schemaLocation="https://logging.apache.org/xml/ns https://logging.apache.org/xml/ns/log4j-changelog-0.xsd"
+       type="fixed">
+  <issue id="3086" link="https://github.com/apache/logging-log4j2/issues/3086"/>
+  <description format="asciidoc">
+    Removed 'patternFlags' @PluginAttribute from RegexFilter @PluginFactory createFilter.
+  </description>
+</entry>