title: Java can't find or load main class when running my program
body: <p>I have a simple program that takes a text file as input and runs kandanes algorithm on it. It compiles fine but I get this error when I try and run it: </p>
  
  <p><code>Error: Could not find or load main class a1_13132334</code></p>
  
  <p>It compiles and runs fine on netbeans ide and their is a class file there but it won't run from the command line. Here is the program: </p>
  
  <pre><code>import java.io.*;
  public class a1_13132334
  {
     public static void main(String [] args) throws IOException
     {
      //make sure the user entered a single text file
      if(args.length == 0 || args.length &gt; 1){
          //display an error if the user didn't enter a file or entered more than one file
          System.out.println("You must enter a single file to read from");
          //exit the program if they didn't have the correct input
          System.exit(0);
      }
      else
      {
      //set up strings for reading in the file
      String values = "";
          String currentLine;
          try {
              // Generate the file stream to the file
              FileInputStream in =  new FileInputStream(args[0]);
              try {
                  // Create data input stream to the file stream
                  BufferedReader myInput = new BufferedReader(new InputStreamReader(in));
                  try {
                      // Loop through the file one line at a time
                      while((currentLine = myInput.readLine()) != null) {  // while loop begins here
                          values += currentLine;
                      }
                  }catch (Exception e) {
                      // If the file is unreadable output error message
                      System.out.println("Error: " + e);
                  }
              }catch (Exception e) {
                  // If the file stream is unaccessable
                  System.out.println("Error: " + e);
              }
          }catch (Exception e) {
              // If the file is unopenable
              System.out.println("failed to open file " + args[0]);
              System.out.println("Error: " + e);
          }
          //split the string containing the data of the file into a string array
          String [] data = values.split(",");
          //create an array of floats to parse the values of the file into and set it to the length of the string array data
          float [] vectors = new float[data.length];
          //a for loop to go through the data array
          for(int i = 0;i&lt; data.length;i++){
          //convert the values in the data string array into floats and put them in the vectors array
          vectors[i] = Float.parseFloat(data[i]);
          }
          //set up the floats and ints that are needed for kandanes alogorithm
          //an int to store the start index
          int maxStartIndex=0;
          //an int to store the final index
          int maxEndIndex=0;
          //a float to store the max sum
          float maxSum = Integer.MIN_VALUE; 
          // a float to store the sum if you add the current index
          float cumulativeSum= 0;
          //an int to store the start index so far
          int maxStartIndexUntilNow=0;
          //a for loop to read through the vectors array      
          for (int i = 0; i &lt; vectors.length; i++) {
              //a float to store the current value of the array
              float eachArrayItem = vectors[i];
              //adding the value of the current index to the sum so far
              cumulativeSum+=eachArrayItem;
              //checking if adding the current value increases the max sum
              if(cumulativeSum&gt;maxSum){
                  //if it does make the maxsum include the value of the current index
                  maxSum = cumulativeSum;
                  //change the initial index to the max start index until now
                  maxStartIndex=maxStartIndexUntilNow;
                  //make the final index the current index
                  maxEndIndex = i;
              }
              //if the current index doesn't increase the maxsum check if it makes it less than 0
              else if (cumulativeSum&lt;0){
                  //change the inital index to the next index
                  maxStartIndexUntilNow=i+1;
                  //reset the cumulative sum
                  cumulativeSum=0;
              }
          }
          //print out the results
          System.out.println("initial index:\t\t\t"+maxStartIndex);
          System.out.println("final index:\t\t\t"+maxEndIndex);
          System.out.println("Value of max-sub vector:\t"+maxSum);
      }
    }
  }
  </code></pre>
  
  <p>It is compiled using this:</p>
  
  <pre><code>javac a1_13132334.java
  </code></pre>
  
  <p>and run with this</p>
  
  <pre><code>java a1_13132334 d:vector25.txt
  </code></pre>
  
  <p>The file also definitely exists and works fine. It is part of a college assignment so it needs to be able to be run from the command line.</p>