Use threading to process file chunk by chunk

Question

I have a arraylist which consists of 5000 IP Addresses. For each IP Address, I want to execute a SNMPGet request and a FTPDownload command. I want to implement it in a fashion,

Answer 1

Herewith adding working example having 5 threads. Just put the test.txt in your CLASS_PATH of the application.

class MyRunnable implements Runnable {
List> records;
MyRunnable(List> records){
    this.records = records;
}
public void run(){
    for(List list : records){
        System.out.println(Thread.currentThread().getName() + " : "+list.toString());
    }
}}

Main Class -

public class FileProcessThreads {
public List> process(String fileName) throws IOException {
    List> records = new ArrayList<>();
    BufferedReader br = new BufferedReader(new FileReader(fileName));
    String line = null;
    while((line = br.readLine()) != null){
        List listValues = Arrays.asList(line.split(" "));
        records.add(listValues);
    }
    System.out.println(records.size());
    return records;
}
public static void main(String[] args) throws IOException {
    FileProcessThreads fp = new FileProcessThreads();
    List> records = fp.process("test.txt");
    ExecutorService es = Executors.newFixedThreadPool(5);
    int recordsInEachThread = (int) (records.size()/5);
    System.out.println(recordsInEachThread);

    MyRunnable my1 = new MyRunnable(records.subList(0, recordsInEachThread));
    MyRunnable my2 = new MyRunnable(records.subList(recordsInEachThread+1, recordsInEachThread*2));
    MyRunnable my3 = new MyRunnable(records.subList(recordsInEachThread*2 + 1, recordsInEachThread*3));
    MyRunnable my4 = new MyRunnable(records.subList(recordsInEachThread*3 + 1, recordsInEachThread*4));
    MyRunnable my5 = new MyRunnable(records.subList(recordsInEachThread*4 + 1, records.size() - 1));
    es.execute(my1);
    es.execute(my2);
    es.execute(my3);
    es.execute(my4);
    es.execute(my5);
    es.shutdown();
}}