Question

I have this method that is supposed to read from a txt file and then print out in the interactions pane the information read. The method works, and I get all the data in the file, but in the end I also get java.util.NoSuchElementException printed out. I know this means that the scanner has reached the end of the file where there is no more data to read, but do not know how to fix the problem. Can someone help me please?

public void parseRecord(String recordFileName){

File recordFile = null;
Fruit fruit = null;
String color = null, name = null;
Scanner sc = null;
PrintWriter output = null;      

try{    
  recordFile = new File(recordFileName);
  sc = new Scanner(recordFile);
  sc.useDelimiter("- *");

  while(sc.hasNext()){
    color = sc.next();
    name = sc.next();

    fruit = new Fruit(color, name);
    System.out.println(fruit);
  }
  sc.close();
}catch(Exception e){
  System.out.println(e);
}  

}

---

  java.util.NoSuchElementException
at java.util.Scanner.throwFor(Unknown Source)
at java.util.Scanner.next(Unknown Source)
at ReadFruits.parseRecord(ReadFruits.java:21)
at ReadFruits.main(ReadFruits.java:41)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:271)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at edu.rice.cs.dynamicjava.symbol.JavaClass$JavaMethod.evaluate(JavaClass.java:362)
at edu.rice.cs.dynamicjava.interpreter.ExpressionEvaluator.handleMethodCall(ExpressionEvaluator.java:92)
at edu.rice.cs.dynamicjava.interpreter.ExpressionEvaluator.visit(ExpressionEvaluator.java:84)
at koala.dynamicjava.tree.StaticMethodCall.acceptVisitor(StaticMethodCall.java:121)
at edu.rice.cs.dynamicjava.interpreter.ExpressionEvaluator.value(ExpressionEvaluator.java:38)
at edu.rice.cs.dynamicjava.interpreter.ExpressionEvaluator.value(ExpressionEvaluator.java:37)
at edu.rice.cs.dynamicjava.interpreter.StatementEvaluator.visit(StatementEvaluator.java:106)
at edu.rice.cs.dynamicjava.interpreter.StatementEvaluator.visit(StatementEvaluator.java:29)
at koala.dynamicjava.tree.ExpressionStatement.acceptVisitor(ExpressionStatement.java:101)
at edu.rice.cs.dynamicjava.interpreter.StatementEvaluator.evaluateSequence(StatementEvaluator.java:66)
at edu.rice.cs.dynamicjava.interpreter.Interpreter.evaluate(Interpreter.java:77)
at edu.rice.cs.dynamicjava.interpreter.Interpreter.interpret(Interpreter.java:47)
at edu.rice.cs.drjava.model.repl.newjvm.InterpreterJVM.interpret(InterpreterJVM.java:246)
at edu.rice.cs.drjava.model.repl.newjvm.InterpreterJVM.interpret(InterpreterJVM.java:220)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.rmi.server.UnicastServerRef.dispatch(Unknown Source)
at sun.rmi.transport.Transport$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(Unknown Source)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

---

I think the problem might be at the txt file I have created. I use – as a delimiter and in the last line of the file I should not put -, meaning
Orange- Orange-
Green- Apple

When I do this I do not get the error anymore

Answer 1

One problem you have is that you aren’t checking hasNext for every time you use next:

while(sc.hasNext()) {
    String color = sc.next();
    if(sc.hasNext()) {
        String name = sc.next();
        Fruit fruit = new Fruit(color, name);
        System.out.println(fruit);
    }
}