Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "^(?:SLF4J:|\\w+(?:\\.\\w+)+).*(?:\\R(?!(?:SLF4J:|\\w+(?:\\.\\w+)+)|\\{).*)*"; final String string = "SLF4J: Class path contains multiple SLF4J bindings.\n" + "SLF4J: Found binding in [jar:file:/opt/spark/jars/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]\n" + "SLF4J: Found binding in [jar:file:/opt/spark/jars/slf4j-log4j12-1.7.30.jar!/org/slf4j/impl/StaticLoggerBinder.class]\n" + "SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.\n" + "SLF4J: Actual binding is of type \n" + "{\"log_timestamp\": \"2021-02-18T11:33:23.114+0000\", \"log_level\": \"WARN\", \"process_id\": \"zookeeper#2\", \"process_name\": \"zookeeper\", \"thread_id\": 1, \"thread_name\": \"QuorumPeer[myid=2](plain=/0.0.0.0:2181)(secure=disabled)\", \"action_name\": \"org.apache.zookeeper.server.quorum.QuorumPeer\", \"log_message\": \"PeerState set to LOOKING\"}\n" + "{\"log_timestamp\": \"2021-02-18T11:33:23.115+0000\", \"log_level\": \"WARN\", \"process_id\": \"zookeeper#2\", \"process_name\": \"zookeeper\", \"thread_id\": 1, \"thread_name\": \"WorkerSender[myid=2]\", \"action_name\": \"org.apache.zookeeper.server.quorum.QuorumPeer\", \"log_message\": \"Failed to resolve address: zk-2.zk-headless.intam.svc.cluster.local\"}\n" + "java.net.UnknownHostException: zk-2.zk-headless.intam.svc.cluster.local\n" + " at java.net.InetAddress.getAllByName0(InetAddress.java:1281)\n" + " at java.net.InetAddress.getAllByName(InetAddress.java:1193)\n" + " at java.net.InetAddress.getAllByName(InetAddress.java:1127)\n" + " at java.net.InetAddress.getByName(InetAddress.java:1077)\n" + " at org.apache.zookeeper.server.quorum.QuorumPeer$QuorumServer.recreateSocketAddresses(QuorumPeer.java:194)\n" + " at org.apache.zookeeper.server.quorum.QuorumPeer.recreateSocketAddresses(QuorumPeer.java:764)\n" + " at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:699)\n" + " at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:618)\n" + " at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:477)\n" + " at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:456)\n" + " at java.lang.Thread.run(Thread.java:748)\n" + "{\"log_timestamp\": \"2021-02-18T11:33:23.115+0000\", \"log_level\": \"WARN\", \"process_id\": \"zookeeper#2\", \"process_name\": \"zookeeper\", \"thread_id\": 1, \"thread_name\": \"WorkerSender[myid=2]\", \"action_name\": \"org.apache.zookeeper.server.quorum.QuorumPeer\", \"log_message\": \"Failed to resolve address: zk-2.zk-headless.sxc.svc.cluster.local\"}\n\n" + "java.lang.InterruptedException: Timeout while waiting for epoch from quorum\n" + " at org.apache.zookeeper.server.quorum.Leader.getEpochToPropose(Leader.java:1227)\n" + " at org.apache.zookeeper.server.quorum.Leader.lead(Leader.java:482)\n" + " at org.apache.zookeeper.server.quorum.QuorumPeer.run(QuorumPeer.java:1284)\n" + " ... 19 more\n" + "{\"log_timestamp\": \"2021-02-18T11:33:23.114+0000\", \"log_level\": \"WARN\", \"process_id\": \"zookeeper#2\", \"process_name\": \"zookeeper\", \"thread_id\": 1, \"thread_name\": \"QuorumPeer[myid=2](plain=/0.0.0.0:2181)(secure=disabled)\", \"action_name\": \"org.apache.zookeeper.server.quorum.QuorumPeer\", \"log_message\": \"PeerState set to LOOKING\"}\n" + "{\"log_timestamp\": \"2021-02-18T11:33:23.115+0000\", \"log_level\": \"WARN\", \"process_id\": \"zookeeper#2\", \"process_name\": \"zookeeper\", \"thread_id\": 1, \"thread_name\": \"WorkerSender[myid=2]\", \"action_name\": \"org.apache.zookeeper.server.quorum.QuorumPeer\", \"log_message\": \"Failed to resolve address: zk-2.zk-headless.intam.svc.cluster.local\"}\n" + "java.net.UnknownHostException: zk-2.zk-headless.intam.svc.cluster.local\n" + " at java.net.InetAddress.getAllByName0(InetAddress.java:1281)\n" + " at java.net.InetAddress.getAllByName(InetAddress.java:1193)\n" + " at java.net.InetAddress.getAllByName(InetAddress.java:1127)\n" + " at java.net.InetAddress.getByName(InetAddress.java:1077)\n" + " at org.apache.zookeeper.server.quorum.QuorumPeer$QuorumServer.recreateSocketAddresses(QuorumPeer.java:194)\n" + " at org.apache.zookeeper.server.quorum.QuorumPeer.recreateSocketAddresses(QuorumPeer.java:764)\n" + " at org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:699)\n" + " at org.apache.zookeeper.server.quorum.QuorumCnxManager.toSend(QuorumCnxManager.java:618)\n" + " at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.process(FastLeaderElection.java:477)\n" + " at org.apache.zookeeper.server.quorum.FastLeaderElection$Messenger$WorkerSender.run(FastLeaderElection.java:456)\n" + " at java.lang.Thread.run(Thread.java:748)\n" + "{\"log_timestamp\": \"2021-02-18T11:33:23.115+0000\", \"log_level\": \"WARN\", \"process_id\": \"zookeeper#2\", \"process_name\": \"zookeeper\", \"thread_id\": 1, \"thread_name\": \"WorkerSender[myid=2]\", \"action_name\": \"org.apache.zookeeper.server.quorum.QuorumPeer\", \"log_message\": \"Failed to resolve address: zk-2.zk-headless.sxc.svc.cluster.local\"}\n\n\n" + "org.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:699) dorg.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManorg.apache.zookeeper.server.quorum.QuorumCnxManager.connectOne(QuorumCnxManager.java:699)"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html