I am new to java and i was trying to do a simple task with the java example of producer and consumer. In my case, i want to "produce" read file , while reading each line i want to stop the thread. another thread "consumer"comes in and saves that list in db . if there is no thread in the list, it will stop and the pre thread will again start reading the next line. I am this far with the code. can you help me understand what i am doing wrong? Thank you. the expectation i had was print 1 line and print "save in db" print another line and print "save in db" . but it's not happening.
import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.util.LinkedList;
public class Processor {
LinkedList<String[]> abc = new LinkedList<String[]>();
int size = 1;
// The name of the file to open.
String fileName = "//Users//wangel//Desktop//Workbook1.csv";
// This will reference one line at a time
String line = null;
private Object lock = new Object();
public void produce() throws InterruptedException{
//get the csv file and read
System.out.println("Starting to read the file");
try {
// FileReader reads text files in the default encoding.
FileReader fileReader = new FileReader(fileName);
// Always wrap FileReader in BufferedReader.
BufferedReader bufferedReader = new BufferedReader(fileReader);
while((line = bufferedReader.readLine()) != null) {
synchronized(lock){
String row[] = line.split(",");
for(int i=0; i<row.length; i++){
System.out.print(row[i] + "\t");
abc.add(row);
}
while(abc.size() == size){
lock.wait();
}
//lock.wait();
System.out.println();
System.out.println("Resumed");
lock.notify();
}
}
// Always close files.
bufferedReader.close();
}
catch(FileNotFoundException ex) {
System.out.println(
"Unable to open file '" +
fileName + "'");
}
catch(IOException ex) {
System.out.println(
"Error reading file '"
+ fileName + "'");
// Or we could just do this:
// ex.printStackTrace();
}
}
public void consume() throws InterruptedException{
//save the input data file in the database
synchronized(lock){
while(true){
while(abc.size() == 0){
lock.wait();
}
lock.notify();
Thread.sleep(2000);
System.out.println("Starting to save in the DB");
abc.removeFirst();
}
}
}
}
The main class
public class Main {
public static void main(String[] args) throws InterruptedException{
// TODO Auto-generated method stub
final Processor processor = new Processor();
Thread t1 = new Thread(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
try {
processor.produce();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
Thread t2 = new Thread(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
try {
processor.consume();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
t1.start();
t2.start();
t1.join();
t2.join();
}
}