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POClassCastException in java
 

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  1. POClassCastException in java
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    <p>I keep getting a ClassCastException </p> <p>Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot be cast to homework5.Creature</p> <pre><code>at ho.Creature.compareTo(Creature.java:11) at java.util.Collections.indexedBinarySearch(Collections.java:215) at java.util.Collections.binarySearch(Collections.java:201) at ho.PC.play(PC.java:61) at ho.Main.main(Main.java:41) </code></pre> <p>Java Result: 1</p> <p>I'm not sure what else I need to give for information</p> <p>Method I have to start things:</p> <pre><code>public void play(PC pc) { Scanner reader = new Scanner(System.in); while (true) { String command = reader.nextLine(); String[] commands = null; if (command.contains(":")) { commands = command.split(":"); ArrayList array = getRoom().getCreatures(); Collections.sort(array); int index = Collections.binarySearch(array, commands[0]); Creature c = getRoom().getCreatures().get(index); //Creature c = getRoom().binarySearchForCreature(commands[0], 0, getRoom().getCount() - 1); if (c != null) { if (commands[1].equalsIgnoreCase("clean")) { c.clean(pc); pc.getRoom().critReactRoomStateChange("clean", pc, c.getName()); } else if (commands[1].equalsIgnoreCase("dirty")) { c.dirty(pc); pc.getRoom().critReactRoomStateChange("dirty", pc, c.getName()); } else if (commands[1].equalsIgnoreCase("n")) { c.tryMove(commands[1], pc); c.checkNewRoom(); } else if (commands[1].equalsIgnoreCase("e")) { c.tryMove(commands[1], pc); c.checkNewRoom(); } else if (commands[1].equalsIgnoreCase("s")) { c.tryMove(commands[1], pc); c.checkNewRoom(); } else if (commands[1].equalsIgnoreCase("w")) { c.tryMove(commands[1], pc); c.checkNewRoom(); } else { System.out.println("Command Does not exist."); } } else { System.out.println("That creature is not in the room."); } ...(Keeps going) </code></pre> <p>After I implemented the Collections.binarySearch I started getting this error I get the error in my creature class. This is the class the top error comes from ho.Creature.compareTo(Creature.java:11) The compareTo is near the bottom. </p> <pre><code>public abstract class Creature implements Comparable&lt;Creature&gt; { protected Room roomRef; private String name; private String descript; public Creature(String name, String descript) { this.name = name; this.descript = descript; } public void setRoom(Room roomRef) { this.roomRef = roomRef; } public Room getRoom() { return this.roomRef; } public String getName() { return this.name; } public void setName(String name) { this.name = name; } public final void clean(PC pc) { String cClass = ""; if (!getRoom().getState().equalsIgnoreCase("clean")) { if (getRoom().getState().equalsIgnoreCase("dirty")) { getRoom().setState("half-dirty"); } else { getRoom().getState().equalsIgnoreCase("half-dirty"); getRoom().setState("clean"); } if (this instanceof Animal) { cClass = "Animal"; System.out.println(getName() + " the " + cClass + " cleans the room " + roomRef.getName() + ". The room's state is now " + roomRef.getState()); reactG(pc); reactG(pc); reactG(pc); } if (this instanceof NPC) { cClass = "NPC"; System.out.println(getName() + " the " + cClass + " cleans the room " + roomRef.getName() + ". The room's state is now " + roomRef.getState()); reactD(pc); reactD(pc); reactD(pc); } if (this instanceof PC) { cClass = "PC"; } } else { System.out.println("The room " + roomRef.getName() + "is already clean."); } } public final void dirty(PC pc) { String cClass = ""; if (!getRoom().getState().equalsIgnoreCase("dirty")) { if (getRoom().getState().equalsIgnoreCase("clean")) { getRoom().setState("half-dirty"); } else { getRoom().getState().equalsIgnoreCase("half-drity"); getRoom().setState("dirty"); } if (this instanceof Animal) { cClass = "Animal"; System.out.println(getName() + " the " + cClass + " dirties the room " + roomRef.getName() + ". The room's state is now " + roomRef.getState()); reactD(pc); reactD(pc); reactD(pc); } if (this instanceof NPC) { cClass = "NPC"; System.out.println(getName() + " the " + cClass + " dirties the room " + roomRef.getName() + ". The room's state is now " + roomRef.getState()); reactG(pc); reactG(pc); reactG(pc); } if (this instanceof PC) { cClass = "PC"; System.out.println(getName() + " the " + cClass + " dirties the room " + roomRef.getName() + ". The room's state is now " + roomRef.getState()); } } else { System.out.println("The room " + roomRef.getName() + "is already dirty."); } } public String getCreatureType() { if ((this instanceof PC)) { return "PC"; } if ((this instanceof NPC)) { return "NPC"; } if ((this instanceof Animal)) { return "Animal"; } return null; } public void reactStateChange(String command, PC pc) { if ((this instanceof NPC)) { if (command.equals("clean")) { reactD(pc); } if (command.equals("dirty")) { reactG(pc); } if (this.roomRef.getState().equalsIgnoreCase("clean")) { tryLeaveRoom(pc); } } if (this instanceof Animal) { if (command.equalsIgnoreCase("clean")) { reactG(pc); } if (command.equals("dirty")) { reactD(pc); } if (this.roomRef.getState().equalsIgnoreCase("dirty")) { tryLeaveRoom(pc); } } } public void checkNewRoom() { if ((this instanceof NPC)) { if (this.roomRef.getState().equalsIgnoreCase("clean")) { this.roomRef.setState("half-dirty"); } } if (this instanceof Animal) { if (this.roomRef.getState().equalsIgnoreCase("dirty")) { this.roomRef.setState("half-dirty"); } } } public void tryMove(String direction, PC pc) { try { Room dest = getRoom().getNeighbor(direction); if (dest.getCreatures().size() &lt;= 9) { getRoom().removeCreature(this); setRoom(getRoom().getNeighbor(direction)); dest.addCreature(this); System.out.println("The " + getCreatureType() + " " + getName() + " left the room and goes to " + dest.getName() + " through the " + changeDirectionName(direction) + " door."); } else { System.out.println("Cannot move " + changeDirectionName(direction) + " to the room " + getRoom().getNeighbor(direction).getName() + " because it is full!"); reactD(pc); } } catch (NullPointerException e) { System.out.println("There is not a neighbor to the " + changeDirectionName(direction) + "!"); reactD(pc); } } private String changeDirectionName(String ref) { if (ref.equalsIgnoreCase("n")) { ref = "north"; return ref; } if (ref.equalsIgnoreCase("s")) { ref = "south"; return ref; } if (ref.equalsIgnoreCase("e")) { ref = "east"; return ref; } if (ref.equalsIgnoreCase("w")) { ref = "west"; return ref; } return null; } public void tryLeaveRoom(PC pc) { boolean allChosen = false; boolean[] chosen = new boolean[4]; while (allChosen == false) { String[] directions = {"n", "e", "s", "w"}; Random dirPick = new Random(); int rNum = dirPick.nextInt(4); String direction = directions[rNum]; Room destRoom = getRoom().getNeighbor(direction); if (chosen[rNum] == false) { if (destRoom != null) { tryMove(direction, pc); break; } chosen[rNum] = true; } if (chosen[0] == true &amp;&amp; chosen[1] == true &amp;&amp; chosen[2] == true &amp;&amp; chosen[3] == true) { allChosen = true; getRoom().removeCreature(this); getRoom().roofAction(pc); System.out.println("The " + getCreatureType() + " " + getName() + "leaves through the roof of " + getRoom().getName()); } } } protected abstract void reactRoom(PC pc); protected abstract void reactG(PC pc); protected abstract void reactD(PC pc); public void look() { String creatureS = ""; System.out.print("The name of the room you are in is " + roomRef.getName() + ". "); System.out.print("\nDescription: " + roomRef.getDescription() + " "); System.out.print("and it's state is " + roomRef.getState() + ".\n"); System.out.print("It contains the creatures: \n"); for (int i = 0; i &lt; roomRef.getCreatures().size(); i++) { creatureS += "\t" + roomRef.getCreatures().get(i).getName()+ "\n"; } // for (int i = 0; i &lt; roomRef.getCreatures().length; i++) { // if (this.roomRef.getCreatures()[i] != null) { // creatureS += "\t" + roomRef.getCreatures()[i] + "\n"; // } // } System.out.println(creatureS); System.out.print("Neighbors:\n"); if (this.roomRef.getNeighbor("n") != null) { System.out.print("\tThe north door is: " + this.roomRef.getNorthD().getName() + "\n"); } else { System.out.print(""); } if (this.roomRef.getNeighbor("s") != null) { System.out.print("\tThe south door is: " + this.roomRef.getSouthD().getName() + "\n"); } else { System.out.print(""); } if (this.roomRef.getNeighbor("e") != null) { System.out.print("\tThe east door is: " + this.roomRef.getEastD().getName() + "\n"); } else { System.out.print(""); } if (this.roomRef.getNeighbor("w") != null) { System.out.print("\tThe west door is: " + this.roomRef.getWestD().getName() + "\n"); } else { System.out.print(""); } } public int compareTo(Creature o) { return this.getName().compareToIgnoreCase(o.getName()); } public String toString() { return name + " is a/an " + this.getCreatureType() + " who is " + descript; } } </code></pre>
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    1. USKirs Kringle
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    1. COPost the stack trace, please. And tell us what lines of the code the line numbers in the trace refer to.
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      1. USQuantumMechanic
    2. COEhm, it is not clear but it seems to me that you perform binary search on a list of Creature type against String key? I am referring to line Collections.binarySearch(array, commands[0]);
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