CODEWITHSUNDEEP
java
Cristian RSS
Cristian RSS

Reputation: 23

Filter a string according to one letter?

I am trying to filter a log according to the type of log. This is an example of a log

--------- beginning of main
04-30 01:16:36.307   458   458 I ADB_SERVICES: serv
04-30 01:16:36.363   458   458 I ADB_SERVICES: service_to_fd 
04-30 01:16:36.371  6181  6181 W sh      : type=140 ino=2 scon
04-30 01:16:36.401  6181  6181 W getprop : type=10 audit(0.0:36): avc: denied
04-30 01:16:36.433   458  6182 I ADB_SERVICES: post waitpid (
04-30 01:16:36.454   458   458 I ADB_SERVICES: service_to_fd

in this example for example I Want to filter only the String line that contains the letter W after the numbers and printed.

This is how I print the log.

List<LogEntry> logEntries = sytemLogs.getLogs();

for (LogEntry entry : sysLogEntries) {
   System.out.println(sysLogEntries.getMessage());
}

Upvotes: 1

Views: 102

Answers (3)

Kaplan
Kaplan

Reputation: 3728

get a list with the corresponding messages in lambda

List<LogEntry> list = logEntries.stream()
  .filter(l -> Pattern.matches("[^A-Z]*W.*", l.getMessage())).collect(toList());

if runtime matters extract the regex as compiled Pattern

Upvotes: 1

vijaydeep
vijaydeep

Reputation: 385

Regular expressions can help here.

Here is a regex that can be used. Read the logs line by line and using this regex perform further operations.

      public void processLogs() {
        String regex = "[\\d] +[W]{1} .*\\b";

        Pattern pattern = Pattern.compile(regex);
        List<LogEntry> logEntries = sytemLogs.getLogs();

        for (LogEntry entry : logEntries) {
          String line = entry.getMessage();
            System.out.println(line);

            Matcher matcher = pattern.matcher(line);
            boolean matchFound = matcher.find();
            if (matchFound) {
                System.out.println("Match found");
                //Other operations
            }
        }
    }

Upvotes: 0

Charchit Kapoor
Charchit Kapoor

Reputation: 9284

Assuming that all the logs contain the equal count of numbers before the character W, say 32, this can be done as follows.

List<LogEntry> logEntries = systemLogs.getLogs();
for(LogEntry entry: logEntries){
   int index = entry.getMessage().indexOf("W");
   if(index == 32){
      System.out.println(entry.getMessage());
   }
}

Upvotes: 1

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