java.util.scanner

I am using 'java.util.Scanner' to read and scan for keywords and want to print the previous 5 lines and next 5 lines of the encountered keyword, below is my code ArrayList<String> keywords = new ArrayList<String>(); keywords.add("ERROR"); keywords.add("EXCEPTION"); java.io.File file = new java.io.File(LOG_FILE); Scanner input = null; try { input = new Scanner(file); } catch (FileNotFoundException e) { e.printStackTrace(); } int count = 0; String previousLine = null; while(input.hasNext()){ String line = input.nextLine(); for(String keyword : keywords){ if(line.contains(keyword)){ //print prev

I have the following data which I want to split up. (1,167,2,'LT2A',45,'Weekly','1,2,3,4,5,6,7,8,9,10,11,12,13'), to obtain each of the values: 1 167 2 'LT2A' 45 'Weekly' '1,2,3,4,5,6,7,8,9,10,11,12,13' I am using the Scanner class to do that and with , as the delimiter. But I face problems due to the last string: ('1,2,3,4,5,6,7,8,9,10,11,12,13') . I would hence like some suggestions on how I could split this data. I have also tried using ,' as the delimiter but the string contains data without ''. The question is quite specific to my needs but I would appreciate if someone could give me

I'm apparently facing an infinite loop on while(input.hasNext()) , as in following code File file = new File("data.txt"); Scanner input = new Scanner(file); int sum = 0; while (input.hasNext()) { if (input.hasNextInt()) { sum += input.nextInt(); } } System.out.println(sum); Some related questions explain why it always returns true if input stream is System.in , however I'm scanning through a File . Please let me know where I'm going wrong. I'm attempting to calculate the sum of unique integer values (space delimited where they occur). Edit: Lesson learned, input.hasNext() does not move the

There are many threads on SO about interrupting reading the system.in but what I am looking for here is some kind of advice as to how to best code what I am trying to achieve. I have a getlogin() method that needs to do the following: ask a user to input the desired login environnement details, if after 6 seconds user have not input a valid value ("live" or "test") then set userlogin variable to "test" and return it to the caller. I have taken the following approach for the getlogin() implementation: launch two threads which do the following: thread1 creates a scanner object then calls scanner

I have a small task that allows the user to enter the regions and their neighbors of any country. I did everything and I just have a small problem which is when I run my code and the program asks the user to enter the number of regions, if the user enters 13 or and number greater than 10, the system will consider that number is like two inputs and it will not allow the user to enter anything for the second question and it will prompt him with the third question immediately. Why? I think the problem with the Scanner class in the following command: Scanner kb = new Scanner(System.in); System.out

I am doing a homework assignment for my Computer Science course. The task is to get a users input, remove all of the vowels, and then print the new statement. I know I could easily do it with this code: string.replaceAll("[aeiou](?!\\b)", "") But my instructor wants me to use nested if and else if statements to achieve the result. Right now I am using something like this: if(Character.isLetter('a')){ 'do something' }else if(Character.isLetter('e')){ 'do something else' But I am not sure what to do inside the if and else if statements. Should I delete the letter? Or is there a better way to do