Please help with search function
Heya, im currently working on code that will allow me to add, view, search and remove prisoners and wardens from a prison system. So far i have managed to allow the user to add and view. Im a bit stuck on the search part of the code, its a bit temperamental :S, sometimes it will find and display the data, but other times it will not and comes up with the error
Exception in thread "main" java.lang.NullPointerException
at Prison.getNum(Prison.java:128)
at TestPrison.main(TestPrison.java:101)
Below i have put my Prison and TestPrison Class files and highlighted the lines the compiler said had the error, any help would be really appreciated because i really cant work out wats going on.
Prison
public class Prison
{
private Prisoner [] thePrisoner;
private Warden [] theWarden;
private HighPrisoner [] theHighPrisoner;
private int maxP;
private int maxPrisoners;
private int maxW;
private int maxWardens;
private int maxH;
private int maxHighPrisoners;
public String prisonName;
public Prison (String prison, int maxP, int maxW, int maxH)
{
prisonName = prison;
maxPrisoners = maxP;
maxP = 0;
thePrisoner = new Prisoner [maxPrisoners];
maxWardens = maxW;
maxW = 0;
theWarden = new Warden [maxWardens];
maxHighPrisoners = maxH;
maxH = 0;
theHighPrisoner = new HighPrisoner [maxHighPrisoners];
}
public boolean addPrisoner( Prisoner newPrisoner )
{
if ( maxP == maxPrisoners )
{
System.out.println("Prisons full");
return false;
}
else
{
System.out.println("Prisoner now in Prison");
thePrisoner[maxP] = newPrisoner;
maxP++;
return true;
}
}
public boolean addHighPrisoner( HighPrisoner newHighPrisoner )
{
if ( maxH == maxHighPrisoners )
{
System.out.println("Prisons full");
return false;
}
else
{
System.out.println("High Level Prisoner now in Prison");
theHighPrisoner[maxH] = newHighPrisoner;
maxH++;
return true;
}
}
public boolean addWarden( Warden newWarden )
{
if ( maxW == maxWardens )
{
System.out.println("We Have Anough Wardens");
return false;
}
else
{
System.out.println("Warden now working at Prison");
theWarden[maxW] = newWarden;
maxW++;
return true;
}
}
public void outputAll()
{
System.out.println("School Name: " + prisonName );
System.out.println("");
outputWardens();
System.out.println("");
outputPrisoners();
System.out.println("");
outputHighPrisoners();
System.out.println("");
}
public void outputWardens()
{
System.out.println("The Wardens:");
for( int i=0; i < maxW; ++i)
{
System.out.println(theWarden);
}
}
public void outputPrisoners()
{
System.out.println("The Low Level Prisoners:");
for( int i=0; i < maxP; ++i)
{
System.out.println(thePrisoner);
}
}
public void outputHighPrisoners()
{
System.out.println("The High Level Prisoners:");
for( int i=0; i < maxH; ++i)
{
System.out.println(theHighPrisoner);
}
}
public void getNum(String num)
{
System.out.println("");
System.out.println("Search for Prisoner ID:");
System.out.println("");
for(Prisoner nextPrisoner : thePrisoner)
{
--> 128if (nextPrisoner.getNum() == num)
{
System.out.println(nextPrisoner);
}
else
{
System.out.println("Sorry no Prisoner ID found");
}
}
for(HighPrisoner nextHighPrisoner : theHighPrisoner)
{
if (nextHighPrisoner.getNum() == num)
{
System.out.println(nextHighPrisoner);
}
else
{
System.out.println("Sorry No Prisoner ID found");
}
}
System.out.println("");
}
}
TestPrison
import java.util.*;
public class TestPrison
{
public static void main(String []args)
{
String sN;
int sS;
String sA;
String tN;
int tS;
int input;
String aN;
int aS;
String aA;
int aL;
String aC;
String pN;
String rN;
Scanner kybd = new Scanner(System.in);
Prison prison0 = new Prison("Alcatraz",200,200,100);
do {
menu();
System.out.println("Enter Option: ");
input = kybd.nextInt();
switch(input) {
case 1:
System.out.println("Enter Name: ");
tN = kybd.next();
System.out.println("Enter Rank: ");
tS = kybd.nextInt();
Warden wardenObject = new Warden(tN,tS);
prison0.addWarden(wardenObject);
System.out.println("\nWarden "+tN+" Added!");
break;
case 2:
System.out.println("Enter Prisoner Security Level: ");
aL = kybd.nextInt();
if (aL > 3)
{
System.out.println("Enter Name: ");
aN = kybd.next();
System.out.println("Enter Remaining Jail Time: ");
aS = kybd.nextInt();
System.out.println("Enter Prisoner ID: ");
aA = kybd.next();
System.out.println("Can Prisoner Share Cell? ");
aC = kybd.next();
HighPrisoner highprisonerObject = new HighPrisoner(aN,aS,aA,aL,aC);
prison0.addHighPrisoner(highprisonerObject);
System.out.println("\nPrisoner " + aA + " Added!");
break;
}
else
{
System.out.println("Enter Name: ");
sN = kybd.next();
System.out.println("Enter Remaining Jail Time: ");
sS = kybd.nextInt();
System.out.println("Enter Prisoner ID: ");
sA = kybd.next();
Prisoner prisonerObject = new Prisoner(sN,sS,sA);
prison0.addPrisoner(prisonerObject);
System.out.println("\nPrisoner " + sA + " Added!");
break;
}
case 3:
prison0.outputAll();
break;
case 4:
prison0.outputWardens();
break;
case 5:
prison0.outputPrisoners();
break;
case 6:
prison0.outputHighPrisoners();
break;
case 7:
prison0.outputPrisoners();
prison0.outputHighPrisoners();
break;
case 8:
System.out.println("Enter Prisoner ID: ");
pN = kybd.next();
> 101prison0.getNum(pN);
break;
default:
System.out.println("Error Selection Does Not Exist");
break;
}
} while(input >= 0);
}
public static void menu() {
System.out.println("");
System.out.println("MAIN MENU");
System.out.println("*********\n");
System.out.println("1. Add Warden\n");
System.out.println("2. Add Prisoner\n");
System.out.println("3. View All\n");
System.out.println("4. View Wardens\n");
System.out.println("5. View Low Level Prisoners\n");
System.out.println("6. View High Level Prisoners\n");
System.out.println("7. View All Prisoners\n");
System.out.println("8. Search Prisoner ID\n\n");
}
}
Once again any help would really be appreciated : )
