java - 如何使用我的所有方法修复“表达式的非法开头”？

Question

我有我的代码。我认为可以，但事实并非如此。在每种方法的开头，它总是告诉我';'。意料之中，这也是“非法表达的开始”。我不知道该如何解决。有人可以帮我解决这些错误吗？

这是错误的示例:

F:\COMP SCI\Topic 29  - Data Structures -- Robin Hood\Problem Set\RobinHoodApp.java:203: error: ';' expected
   void arrayList **()** throws FileNotFoundException();


F:\COMP SCI\Topic 29  - Data Structures -- Robin Hood\Problem Set\RobinHoodApp.java:212: error: illegal start of expression
     **void** output()


F:\COMP SCI\Topic 29  - Data Structures -- Robin Hood\Problem Set\RobinHoodApp.java:212: error: ';' expected
     void output **()**

我的代码:

import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import static java.lang.System.out;
import java.util.ArrayList;
import javax.swing.JFrame;

public class RobinHoodApp{
    public static void main(String[] args) throws FileNotFoundException, IOException    {
        RobinHood app = new RobinHood();
        app.readFile();
        app.arrayList();
        app.wordCount();
        app.countMenAtArms();
        app.writeToFile();
    }
}

class RobinHood extends JFrame
{
    private static final ArrayList<String>words = new ArrayList<>();
    private static Scanner book;
    private static int count;
    private static int wordCount;
    public RobinHood()
    {


        try {
            //        scrubber();


            //Prints All Words 1 by 1: Works!


            book = new Scanner(new File("RobinHood.txt") );
            book.useDelimiter("\r\n");

        } catch (FileNotFoundException ex)
        {
             out.println("Where's your text fam?");
        }
}

    void readFile()
    {

      while(book.hasNext())
        {
                    String text = book.next();
                    out.println(text);
        }

   void arrayList() throws FileNotFoundException();
    {
        Scanner add = new Scanner(new File("RobinHood.txt"));

        while(add.hasNext())
        {
            words.add(add.next());
        }
    }
     void output()
    {
        out.println(words);
    }

    void countMenAtArms()
    {
        //Shows 23 times
        String find = "men-at-arms";
        count = 0;
        int x;
        String text;

         for(x=0; x< wordCount; x++ )
        {
            text = words.get(x);
            text = text.replaceAll("\n", "");
            text = text.replaceAll("\n", "");
            if (text.equals(find))
            {
                count++;
            }

        }
        out.println("The amount of time 'men-at-arms' appears in the book is: " + count);
    }
//    void scrubber()
//    {
//
//    }
//
//

     void wordCount()
     {
        {
           wordCount=words.size();
           out.println("There are "+wordCount+" words in Robin Hood.");
        }
    }

    public void writeToFile()
    {
        File file;

            file = new File("Dominique.dat");
            try (FileOutputStream data = new FileOutputStream(file)) {
                if ( !file.exists() )
                    {
                        file.createNewFile();
                    }

                String wordCountSentence = "There are "+ wordCount +" words in Robin Hood. \n";
                String countTheMen = "The amount of time 'men-at-arms' appears in the book is: " + count;
                byte[] strToBytes = wordCountSentence.getBytes();
                byte[] menToBytes = countTheMen.getBytes();
                data.write(strToBytes);
                data.write(menToBytes);
                data.flush();
                data.close();
            }
            catch (IOException ioe)
            {
               System.out.println("Error");
            }
        }
    }

}

Answer 1

在对Java进行编程时，应使用a Java IDE like Eclipse，它会指出代码中最明显的错误。

您为}方法的while循环后错过了一个readFile()(这是由于Sweeper)。

arrayList()方法中的语法错误。

void arrayList() throws FileNotFoundException();   {

在此定义的末尾没有分号，在末尾也没有括号，您描述的是类，而不是方法。这是正确的方法:

void arrayList() throws FileNotFoundException    {

类文件末尾的1个无用的}。

在代码下方找到具有正确布局且没有语法错误的代码。请下次使用IDE，这样可以避免您的麻烦。

import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import static java.lang.System.out;
import java.util.ArrayList;
import javax.swing.JFrame;

public class RobinHoodApp   {
    public static void main(String[] args) throws FileNotFoundException, IOException    {
        RobinHood app = new RobinHood();
        app.readFile();
        app.arrayList();
        app.wordCount();
        app.countMenAtArms();
        app.writeToFile();
    }
}

class RobinHood extends JFrame
{
    private static final ArrayList<String>words = new ArrayList<>();
    private static Scanner book;
    private static int count;
    private static int wordCount;

    public RobinHood()
    {
        try {
            // Prints All Words 1 by 1: Works!

            book = new Scanner(new File("RobinHood.txt") );
            book.useDelimiter("\r\n");

        } catch (FileNotFoundException ex)
        {
            out.println("Where's your text fam ?");
        }
    }

    void readFile()
    {
        while(book.hasNext())
        {
            String text = book.next();
            out.println(text);
        }
    }

   void arrayList() throws FileNotFoundException
   {
        Scanner add = new Scanner(new File("RobinHood.txt"));

        while(add.hasNext())
        {
            words.add(add.next());
        }
   }

     void output()
     {
        out.println(words);
     }

     void countMenAtArms()
     {
        // Shows 23 times
        String find = "men-at-arms";
        count = 0;
        int x;
        String text;

         for(x=0; x< wordCount; x++ )
         {
            text = words.get(x);
            text = text.replaceAll("\n", "");
            text = text.replaceAll("\n", "");
            if (text.equals(find))
            {
                count++;
            }
         }

         out.println("The amount of time 'men-at-arms' appears in the book is: " + count);
    }

     void wordCount()
     {
        {
           wordCount=words.size();
           out.println("There are "+wordCount+" words in Robin Hood.");
        }
    }

    public void writeToFile()
    {
        File file;

        file = new File("Dominique.dat");
        try (FileOutputStream data = new FileOutputStream(file)) {
            if ( !file.exists() )
            {
                file.createNewFile();
            }

                String wordCountSentence = "There are "+ wordCount +" words in Robin Hood. \n";
                String countTheMen = "The amount of time 'men-at-arms' appears in the book is: " + count;
                byte[] strToBytes = wordCountSentence.getBytes();
                byte[] menToBytes = countTheMen.getBytes();
                data.write(strToBytes);
                data.write(menToBytes);
                data.flush();
                data.close();
            }
            catch (IOException ioe)
            {
               System.out.println("Error");
            }
        }
    }