How to do something every 2 minutes and know which 2 minute interval I have
Consider the following code:
package sim;
import common.*;
public class TrafficLightTester {
public static void main(String [] args) {
// create 4 lights
Light north = new Light(STATE.GO);
Light south = new Light(STATE.GO);
Light east = new Light(STATE.STOP);
Light west = new Light(STATE.STOP);
// Create 6 STATE arrays
STATE[] s1 = {STATE.GO, STATE.GO, STATE.STOP, STATE.STOP};
STATE[] s2 = {STATE.AMBER, STATE.AMBER, STATE.STOP, STATE.STOP};
STATE[] s3 = {STATE.STOP, STATE.STOP, STATE.LEFT, STATE.LEFT};
STATE[] s4 = {STATE.STOP, STATE.STOP, STATE.GO, STATE.GO};
STATE[] s5 = {STATE.STOP, STATE.STOP, STATE.AMBER, STATE.AMBER};
STATE[] s6 = {STATE.LEFT, STATE.LEFT, STATE.STOP, STATE.STOP};
int count = -1;
count++;
if (count == 0 ) {
north.setLightState(s1[0]);
south.setLightState(s1[1]);
east.setLightState(s1[2]);
west.setLightState(s1[3]);
System.out.println("North");
north.showLight();
System.out.println("South");
south.showLight();
System.out.println("East");
east.showLight();
System.out.println("West");
west.showLight();
}
if (count == 150000 ) {
north.setLightState(s2[0]);
south.setLightState(s2[1]);
east.setLightState(s2[2]);
west.setLightState(s2[3]);
System.out.println("North");
north.showLight();
System.out.println("South");
south.showLight();
System.out.println("East");
east.showLight();
System.out.println("West");
west.showLight();
}
if (count == 300000 ) {
north.setLightState(s3[0]);
south.setLightState(s3[1]);
east.setLightState(s3[2]);
west.setLightState(s3[3]);
System.out.println("North");
north.showLight();
System.out.println("South");
south.showLight();
System.out.println("East");
east.showLight();
System.out.println("West");
west.showLight();
}
if (count == 450000 ) {
north.setLightState(s4[0]);
south.setLightState(s4[1]);
east.setLightState(s4[2]);
west.setLightState(s4[3]);
System.out.println("North");
north.showLight();
System.out.println("South");
south.showLight();
System.out.println("East");
east.showLight();
System.out.println("West");
west.showLight();
}
if (count == 600000 ) {
north.setLightState(s5[0]);
south.setLightState(s5[1]);
east.setLightState(s5[2]);
west.setLightState(s5[3]);
System.out.println("North");
north.showLight();
System.out.println("South");
south.showLight();
System.out.println("East");
east.showLight();
System.out.println("West");
west.showLight();
}
if (count == 750000 ) {
north.setLightState(s6[0]);
south.setLightState(s6[1]);
east.setLightState(s6[2]);
west.setLightState(s6[3]);
System.out.println("North");
north.showLight();
System.out.println("South");
south.showLight();
System.out.println("East");
east.showLight();
System.out.println("West");
west.showLight();
// count = 0;
}
}
}
Here's what I need to do in pseudo-code
If I'm at the 0'th minute, set each light to the first state.
If I'm at the 2nd minute, set each light to the second state.
If I'm at the 3rd minute.....
etc.
I don't know enough about threads to use them so I was hoping I could
simulate this by using an incremented integer value, but I would
suspect that from reading other threads in this group, there's no
really accurate way since the JVM will increment them as fast as it
can.
My code works in that it is setting things correctly, but I only want
them to be set at 2 minute intervals, otherwise, there's no way that
traffic will be able to flow.