另一个“无法找到或加载主类包” Java错误

Question

我有一大堆的Java源代码从这个git仓库：https://github.com/kevin-wayne/algs4/

我抽出一切~/Java。提取后，.java文件现在位于~/Java/algs4-master/src/main/java/edu/princeton/cs/algs4。然后我将cd'd放到所述目录中，并按照源代码本身内部的指令编译BinarySearch.java类：javac In.java StdIn.java Out.java StdOut.java BinarySearch.java，完成时没有错误，并生成5个Java .class文件。

但是，运行java edu.princeton.cs.algs4.BinarySearch始终因​​而失败。我相当肯定我的$CLASSPATH是正确的：/home/larssend/Java/algs4-master/src/main/java/edu/princeton/cs/algs4

我的系统是Debian使用OpenJDK 8无头测试。

我该怎么做才能运行编译后的类文件？

这是违规的Java源代码，如果它的需要：

/****************************************************************************** 
* Compilation: javac BinarySearch.java 
* Execution: java BinarySearch whitelist.txt < input.txt 
* Dependencies: In.java StdIn.java StdOut.java 
* Data files: http://algs4.cs.princeton.edu/11model/tinyW.txt 
*    http://algs4.cs.princeton.edu/11model/tinyT.txt 
*    http://algs4.cs.princeton.edu/11model/largeW.txt 
*    http://algs4.cs.princeton.edu/11model/largeT.txt 
* 
* % java BinarySearch tinyW.txt < tinyT.txt 
* 50 
* 99 
* 13 
* 
* % java BinarySearch largeW.txt < largeT.txt | more 
* 499569 
* 984875 
* 295754 
* 207807 
* 140925 
* 161828 
* [367,966 total values] 
* 
******************************************************************************/ 

package edu.princeton.cs.algs4; 

import java.util.Arrays; 

/** 
* The {@code BinarySearch} class provides a static method for binary 
* searching for an integer in a sorted array of integers. 
* <p> 
* The <em>indexOf</em> operations takes logarithmic time in the worst case. 
* <p> 
* For additional documentation, see <a href="http://algs4.cs.princeton.edu/11model">Section 1.1</a> of 
* <i>Algorithms, 4th Edition</i> by Robert Sedgewick and Kevin Wayne. 
* 
* @author Robert Sedgewick 
* @author Kevin Wayne 
*/ 
public class BinarySearch { 

    /** 
    * This class should not be instantiated. 
    */ 
    private BinarySearch() { } 

    /** 
    * Returns the index of the specified key in the specified array. 
    * 
    * @param a the array of integers, must be sorted in ascending order 
    * @param key the search key 
    * @return index of key in array {@code a} if present; {@code -1} otherwise 
    */ 
    public static int indexOf(int[] a, int key) { 
     int lo = 0; 
     int hi = a.length - 1; 
     while (lo <= hi) { 
      // Key is in a[lo..hi] or not present. 
      int mid = lo + (hi - lo)/2; 
      if  (key < a[mid]) hi = mid - 1; 
      else if (key > a[mid]) lo = mid + 1; 
      else return mid; 
     } 
     return -1; 
    } 

    /** 
    * Returns the index of the specified key in the specified array. 
    * This function is poorly named because it does not give the <em>rank</em> 
    * if the array has duplicate keys or if the key is not in the array. 
    * 
    * @param key the search key 
    * @param a the array of integers, must be sorted in ascending order 
    * @return index of key in array {@code a} if present; {@code -1} otherwise 
    * @deprecated Replaced by {@link #indexOf(int[], int)}. 
    */ 
    @Deprecated 
    public static int rank(int key, int[] a) { 
     return indexOf(a, key); 
    } 

    /** 
    * Reads in a sequence of integers from the whitelist file, specified as 
    * a command-line argument; reads in integers from standard input; 
    * prints to standard output those integers that do <em>not</em> appear in the file. 
    * 
    * @param args the command-line arguments 
    */ 
    public static void main(String[] args) { 

     // read the integers from a file 
     In in = new In(args[0]); 
     int[] whitelist = in.readAllInts(); 

     // sort the array 
     Arrays.sort(whitelist); 

     // read integer key from standard input; print if not in whitelist 
     while (!StdIn.isEmpty()) { 
      int key = StdIn.readInt(); 
      if (BinarySearch.indexOf(whitelist, key) == -1) 
       StdOut.println(key); 
     } 
    } 
} 

/****************************************************************************** 
* Copyright 2002-2016, Robert Sedgewick and Kevin Wayne. 
* 
* This file is part of algs4.jar, which accompanies the textbook 
* 
*  Algorithms, 4th edition by Robert Sedgewick and Kevin Wayne, 
*  Addison-Wesley Professional, 2011, ISBN 0-321-57351-X. 
*  http://algs4.cs.princeton.edu 
* 
* 
* algs4.jar is free software: you can redistribute it and/or modify 
* it under the terms of the GNU General Public License as published by 
* the Free Software Foundation, either version 3 of the License, or 
* (at your option) any later version. 
* 
* algs4.jar is distributed in the hope that it will be useful, 
* but WITHOUT ANY WARRANTY; without even the implied warranty of 
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 
* GNU General Public License for more details. 
* 
* You should have received a copy of the GNU General Public License 
* along with algs4.jar. If not, see http://www.gnu.org/licenses. 
******************************************************************************/ 

Answer 1

当您运行

java edu.princeton.cs.algs4.BinarySearch 

JVM将寻找一个BinarySearch类在edu.princeton.cs.algs4封装，映射到edu/princeton/cs/algs4从类路径中的目录开始。所以你的类路径应该是/home/larssend/Java/algs4-master/src/main/java。这样JVM就可以在/home/larssend/Java/algs4-master/src/main/java/edu/princeton/cs/algs4中找到该类。