Can anyone give me a hint?

Question about the task

Log parser (part 1)

Java Collections, Level 7, Lesson 15

Resolved

According to the verification I am only failing when both dates are null. Any suggestions why is it like that ?

Today we're going to write a log parser.

The log file has the following format:
ip username date event status

where:
ip is the IP address from which the user generated the event,
user is the username (one or more words separated by spaces),
date is the date of the event formatted as <day.month.year hour:minute:second>,
event is one of the following events:
LOGIN - a user logged in,
DOWNLOAD_PLUGIN - a user downloaded the plugin,
SEND_MESSAGE - a user sent a message,
ATTEMPT_TASK - a user attempted to complete a task,
COMPLETE_TASK - a user has completed a task.
The ATTEMPT_TASK and COMPLETE_TASK events have one additional parameter, separated from the others by a space: the task number.
status is one of the following event statuses:
OK - the event succeeded,
FAILED - the event failed,
ERROR - an error occurred.

Example of a line from a log file:
"146.34.15.5 Eduard Bentley 05.01.2021 20:22:55 COMPLETE_TASK 48 FAILED".
The log file entries are not necessarily ordered by date: events could be logged in a different order than they occur.

The class that will be responsible for parsing logs is called LogParser.
1.1. Add a LogParser class constructor with a Path logDir parameter that indicates the directory with the logs. There may be several logs. All of them must have the LOG extension.
1.2. Implement the IPQuery interface in the LogParser class:
1.2.1. The getNumberOfUniqueIPs(Date after, Date before) method should return the number of unique IP addresses for the specified period. Hereinafter, if a method has Date after and Date before parameters, then you should only return data related to this period (including the dates represented by the after and before parameters).
If the after parameter is null, then you need to process all entries whose date is less than or equal to the before parameter.
If the before parameter is null, then you need to process all entries whose date is greater than or equal to the after parameter.
If both after and before are null, then you need to process absolutely every entry (without filtering by date).
1.2.2. The getUniqueIPs() method must return a set of all unique IP address. Store each IP address in a String.
1.2.3. The getIPsForUser() method must return the IP addresses that the passed user has worked from.
1.2.4. The getIPsForEvent() method must return the IP addresses that produced the passed event.
1.2.5. The getIPsForStatus() method must return the IP addresses that generated events that ended with the passed status.

You can change the implementation of the main() method as you see fit.

Requirements:

A public LogParser(Path logDir) constructor must be created in the LogParser class.
The LogParser class must support the IPQuery interface.
The getNumberOfUniqueIPs(Date, Date) method should return the number of unique IP addresses for the specified period.
The LogParser class's getUniqueIPs(Date, Date) method must return a set containing all unique IP addresses for the specified period.
The LogParser class's getIPsForUser(String, Date, Date) method must return the IP addresses that the passed user worked from during the specified period.
The LogParser class's getIPsForEvent(Event, Date, Date) method must return the IP addresses that generated the passed event during the specified period.
The LogParser class's getIPsForStatus(Status, Date, Date) method must return the IP addresses that generated events that ended with the specified status during the specified period.

package com.codegym.task.task39.task3913; import java.io.IOException; import java.nio.file.Paths; import java.text.ParseException; import java.util.Date; public class Solution { public static void main(String[] args) throws IOException, ParseException { LogParser logParser = new LogParser(Paths.get("/home/volodya/Downloads/test-files/")); System.out.println(logParser.getNumberOfUniqueIPs(null, null)); System.out.println(logParser.getUniqueIPs(null, null)); System.out.println(logParser.getIPsForEvent(Event.LOGIN,null, new Date())); System.out.println(logParser.getIPsForUser("George Bentley" ,null, null)); System.out.println(logParser.getIPsForStatus(Status.OK, null, null)); } }

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Level 41 , Sofia, Bulgaria

13 May 2021, 12:07

solution

I've got it. In the methods getIPsForStatus and getIPsForEvent I had to use regex to filter out events and statuses. Here's what I did in case that it could be helpful:

@Override
public Set<String> getIPsForEvent(Event event, Date after, Date before) throws IOException, ParseException {
    List<String> lines = processDate(after, before, Files.newDirectoryStream(logDir));
    Set<String> ips = new HashSet<>();
    Pattern eventPattern = Pattern.compile("[A-Z]{2,}_[A-Z]+|[A-Z]{2,}");
    Pattern ipsPattern = Pattern.compile("\\d+.\\d+.\\d+.\\d+");
    for (String line : lines) {
    Matcher m = eventPattern.matcher(line);
    if(m.find())
        if((m.group(0)).equals(event.toString())){
            m = ipsPattern.matcher(line);
            if(m.find())
            ips.add(m.group(0));
        }
    }
    return ips;
}

@Override
public Set<String> getIPsForStatus(Status status, Date after, Date before) throws IOException, ParseException {
    List<String> lines = processDate(after, before, Files.newDirectoryStream(logDir));
    Set<String> ips = new HashSet<>();
    Pattern ipsPattern = Pattern.compile("\\d+.\\d+.\\d+.\\d+");
    Pattern statusPattern = Pattern.compile("([A-Z]{2,})+");
    for (String line: lines) {
        Matcher m = statusPattern.matcher(line);
        String statusStr = null;
        while (m.find()){//here we capture the last occurrence of the regex in every line.
            statusStr = m.group();
        }

        if(statusStr.equals(status.toString())){
            m = ipsPattern.matcher(line);
            if(m.find())
            ips.add(m.group(0));
        }
    }

    return ips;
}

Guadalupe Gagnon

Level 37 , Tampa, United States

7 May 2021, 14:18

If I were to guess its that using .before() and .after() would return false if the dates were equal. The task says that if only the before date is null then you should just consider the after date; if only the after date is null then you should consider just the before date; and if both before and after are null then you should add everything. If you had someone whose date equaled 0 or Long.MAX_VALUE (as I am sure codegym would add into testing), they would be filtered out of the result.

Level 41 , Sofia, Bulgaria

11 May 2021, 08:51

Unfortunately it is not this. The validation often returns incorrect errors. Plus I am using the same logic to filter out dates for all of my methods. Some of them pass, some don't. P.S. The getIPsForUser method also passed. I had incorrect regex logic for it. Now I will keep digging for the rest of the methods.