CODEWITHSUNDEEP
javastatictreemapsymbol-table
DomV_04
DomV_04

Reputation: 1

How can I avoid making this static reference to a non-static field?

I'm currently trying to create a symbol table using the Map and treeMap packages, but when I try to add an item into the table, I get this error: "Cannot make a static reference to the non-static field STTM".

SymbolTableTM class:

import java.util.Map;
import java.util.TreeMap;

public class SymbolTableTM<Key extends Comparable<Key>, Value> {
    
    Map<Key, Value> treeMap = new TreeMap<>();
    
    public SymbolTableTM() {
        
    }
    
    public int[] min() {
        int min = Integer.MAX_VALUE;
        int[] min_arr = new int[2];
        for(Map.Entry<Key, Value> entry: treeMap.entrySet()) {
            if((Integer) entry.getValue() < min) {
                min = (Integer) entry.getValue();
                min_arr[0] = (Integer) entry.getKey();
                min_arr[1] = min;
            }
        }
        return min_arr;
    }
    
    public int[] max() {
        int max = Integer.MIN_VALUE;
        int[] max_arr = new int[2];
        for(Map.Entry<Key, Value> entry: treeMap.entrySet()) {
            if((Integer) entry.getValue() > max) {
                max = (Integer) entry.getValue();
                max_arr[0] = (Integer) entry.getKey();
                max_arr[1] = max;
            }
        }
        return max_arr;
    }
    
    public void delete(Key key) {
        treeMap.remove(key);
    }
    
    public Value get(Key key) {
        return treeMap.get(key);
    }
    
    public void put(Key key, Value val) {
        treeMap.put(key, val);
    }   
}

DriverTM class:

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;

public class DriverTM<Key extends Comparable<Key>, Value> {
    
    SymbolTableTM<Key, Value> STTM = new SymbolTableTM<>();
    
    public static void main(String[] args) {
        
        try {
            File myFile = new File("lab3in.txt");
            Scanner scanner = new Scanner(myFile);
            while(scanner.hasNext()) {
                
                STTM.put((Integer) scanner.nextInt(), (Integer) scanner.nextInt());
            }
            scanner.close();
        }
        catch(FileNotFoundException e){
            System.out.println("An error occurred");
            e.printStackTrace();
        }
    }
}

My issue is on line 16 of the DriverTM class.

I thought using an object (STTM) to refer to a non static field wouldn't be an issue, but obviously I'm missing something. Any help appreciated.

Upvotes: 0

Views: 30

Answers (0)

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