摩尔斯电码不是 Working/Running

Question

尝试运行我的代码时总是出现以下错误：

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 0 at MorseCodeToPlainText.main(MorseCodeToPlainText.java:13)

这是我的代码：

public class MorseCodeToPlainText {
  public static void main(String[] args) throws IOException {

    BufferedReader br = new BufferedReader(new FileReader(args[0])); 
    StringBuilder sb = new StringBuilder`enter code here`(); 

    String line = br.readLine(); 
    while (line != null) { 
        sb.append(line).append("\n"); 
        line = br.readLine(); 
    } 

    String fileAsString = sb.toString();

    System.out.println(fileAsString);

    String []morseCodes = fileAsString.split(" | ");

    String plainText = "";
    for(int i=0; i<morseCodes.length; i++)
    {
        plainText += decode(morseCodes[i]);
    }

    System.out.println(plainText);

    writeDataToFile("decoded.txt", plainText);
}

public static String decode (String mCode) {
    String pCode = " ";

    if (mCode.equals(".-"))
        pCode = "A";
    else if (mCode.equals("-..."))
        pCode = "B";
    else if (mCode.equals("-.-."))
        pCode = "C";
    else if (mCode.equals("-.."))
        pCode = "D";
    else if (mCode.equals("."))
        pCode = "E";
    else if (mCode.equals("..-."))
        pCode = "F";
    else if (mCode.equals("--."))
        pCode = "G";
    else if (mCode.equals("...."))
        pCode = "H";
    else if (mCode.equals(".."))
        pCode = "I";
    else if (mCode.equals(".---"))
        pCode = "J";
    else if (mCode.equals("-.-"))
        pCode = "K";
    else if (mCode.equals(".-.."))
        pCode = "L";
    else if (mCode.equals("--"))
        pCode = "M";
    else if (mCode.equals("-."))
        pCode = "N";
    else if (mCode.equals("---"))
        pCode = "O";
    else if (mCode.equals(".--."))
        pCode = "P";
    else if (mCode.equals("--.-"))
        pCode = "Q";
    else if (mCode.equals(".-."))
        pCode = "R";
    else if (mCode.equals("..."))
        pCode = "S";
    else if (mCode.equals("-"))
        pCode = "T";
    else if (mCode.equals("..-"))
        pCode = "U";
    else if (mCode.equals("...-"))
        pCode = "V";
    else if (mCode.equals(".--"))
        pCode = "W";
    else if (mCode.equals("-..-"))
        pCode = "X";
    else if (mCode.equals("-.--"))
        pCode = "Y";
    else if (mCode.equals("--.."))
        pCode = "Z";
    else if (mCode.equals("-----"))
        pCode = "0";
    else if (mCode.equals(".----"))
        pCode = "1";
    else if (mCode.equals("..---"))
        pCode = "2";
    else if (mCode.equals("...--"))
        pCode = "3";
    else if (mCode.equals("....-"))
        pCode = "4";
    else if (mCode.equals("....."))
        pCode = "5";
    else if (mCode.equals("-...."))
        pCode = "6";
    else if (mCode.equals("--..."))
        pCode = "7";
    else if (mCode.equals("---.."))
        pCode = "8";
    else if (mCode.equals("----."))
        pCode = "9";
    else if (mCode.equals(".-.-.-"))
        pCode = ".";
    else if (mCode.equals("--..--"))
        pCode = ",";
    else if (mCode.equals("-..-."))
        pCode = "/";
    else if (mCode.equals("..--.."))
        pCode = "?";

    return pCode;
}

public static void writeDataToFile(String fileName, String fileText){

    FileWriter fw = null;
    BufferedWriter bw = null;
    PrintWriter pw = null;

    try {

        fw = new FileWriter(fileName);
        bw = new BufferedWriter(fw);
        pw = new PrintWriter(bw);

        pw.println(fileText);

        pw.flush();
        pw.close();
        bw.close();
        fw.close();
    }
    catch (IOException io) {
        System.out.println("Problem ocurred during file operation...");
     }
  }
}

Answer 1

您正在使用第一个参数构建 BufferedReader.args[0]。 BufferedReader br = new BufferedReader(new FileReader(args[0]));

当您运行这个程序时，您应该将文件路径作为命令行参数传递。还将 StringBuilder 声明更正为 StringBuilder sb = new StringBuilder("enter code here");

Answer 2

如果您询问如何在 Eclipse 中传递命令行参数。这张截图应该会有帮助。

摩尔斯电码不是 Working/Running

Morse Code Not Working/Running

java

eclipse

morse-code