Java call method reporting

Hello, great gods. Originally, I wanted to write a code as follows, but my report is as follows. I just want to find out where it went wrong:

Exception in thread "main" java.lang.RuntimeException: Uncompilable source code-non-static method isKeyRow (java.lang.String) cannot be referenced from a static context
at javaapplication3.JavaApplication3.main (JavaApplication3.java:12)
Claze UsersViviAppDataLocalNetBeansCache8.2executorlysnippetsrun.xml second 53: Java returned: 1 BUILD FAILED (total time: 1 second)

I am a novice at java, can I help you?

package javaapplication3;

import java.util.Scanner;

public class JavaApplication3 {
public static void main(String[] args) {
      System.out.println(isKeyRow("user"));
    }
    
   public boolean isKeyRow(String user){
    String string1="qwertyuiop";
    String string2="asdfghjkl";
    String string3="zxcvbnm";
        Character u;
       boolean b=true;
       for(int i=0;i<user.length();iPP){
        u=user.charAt(i);
        for(int a=0;a<string1.length();aPP){
            if(string1.charAt(a)!=u){
                b=false;
                break;
            }
        }
        for(int a=0;a<string2.length();aPP){
             if(string2.charAt(a)!=u){
                b=false;
                 break;
            }
        }
        for(int a=0;a<string3.length();aPP){
             if(string3.charAt(a)!=u){
              b=false;
              break;
            }
        return b;
        }
  
       }
Jun.30,2021

static main methods cannot access non-static variables or methods

MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3f430-2c45e.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3f430-2c45e.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?