的NoClassDefFoundError當這個代碼

Question

我從這裏複製該代碼：http://rosettacode.org/wiki/Dining_philosophers#Java

package diningphilosophers; 

import java.util.ArrayList; 
import java.util.Random; 
import java.util.concurrent.atomic.AtomicBoolean; 
import java.util.concurrent.atomic.AtomicInteger; 

enum PhilosopherState { Get, Eat, Pon } 

class Fork { 
    public static final int ON_TABLE = -1; 
    static int instances = 0; 
    public int id; 
    public AtomicInteger holder = new AtomicInteger(ON_TABLE); 

    Fork() { id = instances++; } 
} 

class Philosopher implements Runnable { 
    static final int maxWaitMs = 100;       // must be > 0 
    static AtomicInteger token = new AtomicInteger(0); 
    static int instances = 0; 
    static Random rand = new Random(); 
    AtomicBoolean end = new AtomicBoolean(false); 
    int id; 
    PhilosopherState state = PhilosopherState.Get; 
    Fork left; 
    Fork right; 
    int timesEaten = 0; 

    Philosopher() { 
     id = instances++; 
     left = Main.forks.get(id); 
     right = Main.forks.get((id+1)%Main.philosopherCount); 
    } 

    void sleep() { try { Thread.sleep(rand.nextInt(maxWaitMs)); } 
     catch (InterruptedException ex) {} } 

    void waitForFork(Fork fork) { 
     do { 
      if (fork.holder.get() == Fork.ON_TABLE) { 
       fork.holder.set(id);    // my id shows I hold it 
       return; 
      } else {        // someone still holds it 
       sleep();       // check again later 
      } 
     } while (true); 
    } 

    public void run() { 
     do { 
      if (state == PhilosopherState.Pon) { // all that pondering 
       state = PhilosopherState.Get;  // made me hungry 
      } else { // ==PhilosopherState.Get 
       if (token.get() == id) {   // my turn now 
        waitForFork(left); 
        waitForFork(right);    // Ah needs me some foahks! 
        token.set((id+2)% Main.philosopherCount); 
        state = PhilosopherState.Eat; 
        timesEaten++; 
        sleep();      // eat for a while 
        left.holder.set(Fork.ON_TABLE); 
        right.holder.set(Fork.ON_TABLE); 
        state = PhilosopherState.Pon; // ponder for a while 
        sleep(); 
       } else {     // token.get() != id, so not my turn 
        sleep(); 
       } 
      } 
     } while (!end.get()); 
    } 
} 

public class Main { 
    static final int philosopherCount = 5; // token +2 behavior good for odd #s 
    static final int runSeconds = 15; 
    static ArrayList<Fork> forks = new ArrayList<Fork>(); 
    static ArrayList<Philosopher> philosophers = new ArrayList<Philosopher>(); 

    public static void main(String[] args) { 
     for (int i = 0 ; i < philosopherCount ; i++) forks.add(new Fork()); 
     for (int i = 0 ; i < philosopherCount ; i++) 
      philosophers.add(new Philosopher()); 
     for (Philosopher p : philosophers) new Thread(p).start(); 
     long endTime = System.currentTimeMillis() + (runSeconds * 1000); 

     do {             // print status 
      StringBuilder sb = new StringBuilder("|"); 

      for (Philosopher p : philosophers) { 
       sb.append(p.state.toString()); 
       sb.append("|");   // This is a snapshot at a particular 
      }        // instant. Plenty happens between. 

      sb.append("  |"); 

      for (Fork f : forks) { 
       int holder = f.holder.get(); 
       sb.append(holder==-1?" ":String.format("P%02d",holder)); 
       sb.append("|"); 
      } 

      System.out.println(sb.toString()); 
      try {Thread.sleep(1000);} catch (Exception ex) {} 
     } while (System.currentTimeMillis() < endTime); 

     for (Philosopher p : philosophers) p.end.set(true); 
     for (Philosopher p : philosophers) 
      System.out.printf("P%02d: ate %,d times, %,d/sec\n", 
       p.id, p.timesEaten, p.timesEaten/runSeconds); 
    } 
} 

編譯是好的。但在運行時，它會給出NoClassDefFoundError。爲什麼？我已檢查並發現類名稱沒問題。我甚至嘗試將它們重命名。但沒用。

截圖：

Answer 1

1）創建一個名爲diningphilosophers

2）目錄放在那裏，你的主類最多

3）一個級別的目錄，請致電：

javac diningphilosophers/Main.java 

然後

java diningphilosophers.Main