Java can';运行程序时找不到或加载主类
我有一个简单的程序,将文本文件作为输入,并在其上运行kandanes算法。它可以很好地编译,但当我尝试运行它时,会出现以下错误:Java can';运行程序时找不到或加载主类,java,runtime,runtime-error,Java,Runtime,Runtime Error,我有一个简单的程序,将文本文件作为输入,并在其上运行kandanes算法。它可以很好地编译,但当我尝试运行它时,会出现以下错误: 错误:无法找到或加载主类a1_13132334 它在netbeans ide上编译并运行良好,并且它们的ide是一个类文件,但它不会从命令行运行。节目如下: import java.io.*; public class a1_13132334 { public static void main(String [] args) throws IOException
错误:无法找到或加载主类a1_13132334
它在netbeans ide上编译并运行良好,并且它们的ide是一个类文件,但它不会从命令行运行。节目如下:
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 > 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< 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 < 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>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<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);
}
}
}
带着这个跑
java a1_13132334 d:vector25.txt
该文件也确实存在并且工作正常。它是大学作业的一部分,因此需要能够从命令行运行。当我编译您提供的代码时
javac a1_13132334.java
然后运行它
java a1_13132334 temp.txt
我可以很好地看到程序输出(嗯,我至少得到了一个数字格式的异常)。我想说的是,确保编译后检查.class文件,并确保位于正确的目录中
也许可以尝试以您的代码为例,将其放在一个新文件中,而不在新位置使用netbeans,然后尝试编译和运行它
如果没有帮助,您可以参考以下内容:try
java-cp。a1_13132334 d:vector25.txt
你能看到目录中的a1_13132334.class
吗?您确定没有包声明吗?如果您找到了问题的解决方案,您应该将其中一个解决方案标记为正确答案。出于某种原因,只需将代码复制到新文件中即可
java a1_13132334 temp.txt