Was auch immer ich versuche lösen mit der Linie bTree.binaryTree[i].Data=in.nextLine();
in Framework-Klasse Ergebnisse inkann nicht java.lang.NullPointerException
Geben Sie die Anzahl der Knoten im Binary Tree zu tun: Ausnahme in thread „main "java.lang.NullPointerException zum Knoten # 0 bei binaryTree.framework.intialize (framework.java:19) Geben Sie Daten: bei binaryTree.main.main (main.java:9) Prozess beendet mit Exit-Code 1
Gith ub Kern: https://gist.github.com/D-codex/0051d59abb91fafc73fbec0fa7dad356
EDITED: https://gist.github.com/D-codex/009a5afa391c760b7ecc88f8109662c0 (nach folgenden GhostCat Vorschlag)
Ich habe mein Bestes getan, fast alles zu initialisieren ‚Null‘ überall zu vermeiden, aber diese Ausnahme immer wieder erscheint
Knoten Klasse
package binaryTree;
import java.util.*;
public class node {
boolean hasLeft,hasRight;
boolean isRootPrimary,isRoot;
String Data;
String nodeID,leftNodeID,rightNodeID,parentID;
int childrenNodeCount;
node(){
hasLeft=false;
hasRight=false;
Data="";
childrenNodeCount=0;
}
void check(){
if(hasLeft||hasRight)
isRoot=true;
}
String fetchRoot(){
return parentID;
}
String fetchID(){
return nodeID;
}
String fetchSiblingID(){
return "("+String.valueOf(leftNodeID)+" "+String.valueOf(rightNodeID)+")";
}
}
Tree-Klasse
package binaryTree;
import java.util.*;
public class Tree extends node{
node binaryTree[];
int count;int rootID,height,depth;
String siblingPairs,leaves;
Tree(int count){
binaryTree=new node[count];
this.count=count;
rootID=0;
height=0;depth=0;
}
void finalise(){
for(int i=0;i<count;i++){
if(binaryTree[i].childrenNodeCount==0)
leaves=String.valueOf(binaryTree[i].fetchID());
if(binaryTree[i].childrenNodeCount==2){
siblingPairs=binaryTree[i].fetchSiblingID();
}
}
StringTokenizer st=new StringTokenizer(leaves);
while(st.hasMoreElements()){
int counter=0;
int leafID=Integer.valueOf(st.nextToken());
node temp=binaryTree[leafID];
while(temp.isRootPrimary){
temp=binaryTree[Integer.valueOf(temp.fetchRoot())];
counter=counter+1;
}
if(counter>height) {
height = counter;
depth=height-1;
}
}
}
}
Framework-Klasse
package binaryTree;
import java.util.*;
public class framework {
public Tree intialize(){
System.out.print("Enter the Number of Nodes in the Binary Tree :");
Scanner in=new Scanner(System.in);
int count=in.nextInt();
Tree bTree=new Tree(count);
int ID=0;int i=0;
while(i<count){
System.out.println("Details for node#"+i);
System.out.print("Enter Data :");
bTree.binaryTree[i].Data=in.nextLine();
bTree.binaryTree[i].nodeID=String.valueOf(ID);
if(i!=0){
boolean flag = true;
while (flag) {
String parentID="";
System.out.print("Enter the node's Parent:");
parentID = in.nextLine();
if (bTree.binaryTree[Integer.valueOf(parentID)].childrenNodeCount >= 2) {
System.out.println("Parent Node is Full");
}
else {
bTree.binaryTree[i].parentID = in.nextLine();
bTree.binaryTree[Integer.valueOf(parentID)].childrenNodeCount=bTree.binaryTree[Integer.valueOf(parentID)].childrenNodeCount+1;
flag=false;
}
}
System.out.print("Is the node Parent's Left?");
String temp=in.next();
if(temp.equalsIgnoreCase("yes")||temp=="1"||temp.equalsIgnoreCase("y")){
bTree.binaryTree[Integer.valueOf(bTree.binaryTree[i].parentID)].hasLeft=true;
bTree.binaryTree[Integer.valueOf(bTree.binaryTree[i].parentID)].leftNodeID=bTree.binaryTree[i].nodeID;
}
else {
bTree.binaryTree[Integer.valueOf(bTree.binaryTree[i].parentID)].hasRight = true;
bTree.binaryTree[Integer.valueOf(bTree.binaryTree[i].parentID)].rightNodeID=bTree.binaryTree[i].nodeID;
}
}
else
bTree.binaryTree[i].isRootPrimary=true;
bTree.binaryTree[i].check();
i=i+1;ID=ID+1;
}
bTree.finalise();
return bTree;
}
public void displayAll(Tree bTree){
System.out.println("Running a Full Analysis on the Binary Tree");
System.out.println("Printing nodes Details");
for(int i=0;i<bTree.count;i++){
System.out.println("Node #"+i);
System.out.println("PrimaryRoot :"+bTree.binaryTree[i].isRootPrimary);
System.out.println("isRoot :"+bTree.binaryTree[i].isRoot);
System.out.println("Data :"+bTree.binaryTree[i].Data);
System.out.println("Number of Children Nodes :"+bTree.binaryTree[i].childrenNodeCount);
System.out.println("hasLeft :"+bTree.binaryTree[i].hasLeft);
if(bTree.binaryTree[i].hasLeft)
System.out.println("LeftNodeID :"+bTree.binaryTree[i].leftNodeID);
System.out.println("hasRight :"+bTree.binaryTree[i].hasRight);
if(bTree.binaryTree[i].hasRight)
System.out.println("RightNodeID :"+bTree.binaryTree[i].rightNodeID);
System.out.println("parentID :"+bTree.binaryTree[i].fetchRoot());
System.out.println("SiblingPairs (if any) :"+bTree.binaryTree[i].fetchSiblingID());
System.out.println("____________________________________________________________________________");
}
System.out.println("Tree Specifications");
System.out.println("Total No. of Nodes :"+bTree.count);
System.out.println("Height of Tree :"+bTree.height);
System.out.println("Depth of Tree :"+bTree.depth);
System.out.println("Leaves :"+bTree.leaves);
System.out.println("Sibling Pairs :"+bTree.siblingPairs);
}
}
Hauptklasse
package binaryTree;
public class main {
public static void main(String Args[]){
framework Framework=new framework();
Tree binaryTree=Framework.intialize();
Framework.displayAll(binaryTree);
}
}
Mögliche Duplikate von [Was ist eine NullPointerException, und wie behebe ich es?] (Http://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix -it) –
Befolgen Sie die Java Namenskonventionen, wenn Sie nicht wissen, gehen Sie und lesen Sie es. –
Danke für die schnelle Annahme. Wenn ich nächste Woche etwas Zeit finde, werde ich ein paar Vorschläge für dich machen. – GhostCat