java - 编写了一个程序，但不断收到 ')' 、 ';' 和非法开始表达式错误？ (java)

Question

我必须编写一个程序，它接受一个名为目录的文本文件，并且我有两个类。类目录包含所有可能的操作，例如添加名称、检查名称是否存在、删除名称，然后将更新的目录写回文本文件。 DirectoryWithObjectDesign 类具有 main 方法，用于打开目录、处理用户交互并在完成后关闭目录。

这是 DirectoryWithObjectDesign 类:

    import java.io.*;
import java.util.*;
public class DirectoryWithObjectDesign {
   public static void main(String[] args) throws IOException {
   String directoryDataFile  = "Directory.txt";
   Directory d = new Directory(directoryDataFile);
   Scanner stdin = new Scanner(System.in);
   System.out.println("Directory Server is Ready!");
   System.out.println("Format: command name");
   System.out.println("Enter ^Z to end");
   while (stdin.hasNext()) {
      String command = stdin.next();
      String name = stdin.next();
      if (command.equalsIgnoreCase("find")) {
         if (d.inDirectory(name))
            System.out.println(name + " is in the directory");
         else 
            System.out.println(name + " is NOT in the directory");
      }
      else if (command.equalsIgnoreCase("add")) {
         if (d.add(name))
            System.out.println(name + " added");
         else 
            System.out.println(name + " cannot add! " + "no more space or already in directory");
      }
      else if (command.equalsIgnoreCase("delete")) {
         if (d.delete(name))
            System.out.println(name + " deleted");
         else
            System.out.println(name + " NOT in directory");
      }
      else {
         System.out.println("bad command, try again");
      }
   }
   }
}   

这是类目录

import java.util.*;
import java.io.*;
public class Directory {
   public static void main(String[] args) {
   final int maxDirectorySize = 1024;
   String directory[] = new String[maxDirectorySize];
   int directorySize = 0;
   File directoryFile = null;
   Scanner directoryDataIn = null;
   Directory(String directoryFileName) {
      directoryFile = new File(directoryFileName);
      try {
         directoryDataIn = new Scanner(directoryFile);
      }
      catch (FileNotFoundException e) {
         System.out.println("File is not found, exiting!", 
                           directoryFileName);
         System.exit(0);
      }
      while (directoryDataIn.hasNext()) {
         directory[directorySize++] = directoryDataIn.nextLine();
      }
   public boolean inDirectory(String name) {
      for (int i = 0; i < directory.length; i++) {
         if (directory[i].equalsIgnoreCase(name)) 
            return true;
         else 
            return false;
      }
   }
   public boolean add(String name) {
      if (directory.length == 1024)
         return false;
      for (int i = 0; i < directory.length; i++) {
         if (directory[i].equalsIgnoreCase(name))
            return false;
         else
            directory[directorySize++] = name;
            return true;
      }
   }          

   public boolean delete(String name) {
      for (int i = 0; i < directory.length; i++) {
         if (directory[i].equalsIgnoreCase(name)) {
            directory[i] = null;
            return true;
         }   
         else
            return false;
      }
   }

   public void closeDirectory() {
      directoryDataIn.close();
      PrintStream driectoryDataOut = null;
      try {
         directoryDataOut = new PrintStream(directoryFile);
      }
      catch (FileNotFoundException e) {
         System.out.printf("File %s not found, exiting!", directoryFile);
         System.exit(0);
      }
      String originalDirectory[] = {"Mike","Jim","Barry","Cristian","Vincent","Chengjun","susan","ng","serena"};
      if (originalDirectory == directory)
         System.exit(0);
      else
         for (int i = 0; i < directorySize; i++)
            directoryDataOut.println(directory[i]);
         directoryDataOut.close();
   }
}

这些是我尝试运行 DirectoryWithObjectDesign 时出现的错误

Directory.java:10: error: ')' expected
   Directory(String directoryFileName) {
                   ^
Directory.java:10: error: illegal start of expression
   Directory(String directoryFileName) {
                                     ^
Directory.java:10: error: ';' expected
   Directory(String directoryFileName) {
                                      ^
Directory.java:23: error: illegal start of expression
   public boolean inDirectory(String name) {
   ^
Directory.java:23: error: ';' expected
   public boolean inDirectory(String name) {
                             ^
Directory.java:23: error: ';' expected
   public boolean inDirectory(String name) {
                                         ^
Directory.java:31: error: illegal start of expression
   public boolean add(String name) {
   ^
Directory.java:31: error: ';' expected
   public boolean add(String name) {
                     ^
Directory.java:31: error: ';' expected
   public boolean add(String name) {
                                 ^
Directory.java:43: error: illegal start of expression
   public boolean delete(String name) {
   ^
Directory.java:43: error: ';' expected
   public boolean delete(String name) {
                        ^
Directory.java:43: error: ';' expected
   public boolean delete(String name) {
                                    ^
Directory.java:54: error: illegal start of expression
   public void closeDirectory() {
   ^
Directory.java:54: error: illegal start of expression
   public void closeDirectory() {
          ^
Directory.java:54: error: ';' expected
   public void closeDirectory() {
                             ^
Directory.java:72: error: reached end of file while parsing
}
 ^
DirectoryWithObjectDesign.java:6: error: constructor Directory in class Directory cannot be applied to given types;
   Directory d = new Directory(directoryDataFile);
                 ^
  required: no arguments
  found: String
  reason: actual and formal argument lists differ in length
DirectoryWithObjectDesign.java:15: error: cannot find symbol
         if (d.inDirectory(name))
              ^
  symbol:   method inDirectory(String)
  location: variable d of type Directory
DirectoryWithObjectDesign.java:21: error: cannot find symbol
         if (d.add(name))
              ^
  symbol:   method add(String)
  location: variable d of type Directory
DirectoryWithObjectDesign.java:27: error: cannot find symbol
         if (d.delete(name))
              ^
  symbol:   method delete(String)
  location: variable d of type Directory
Directory.java:10: error: cannot find symbol
   Directory(String directoryFileName) {
             ^
  symbol:   variable String
  location: class Directory
Directory.java:11: error: cannot find symbol
      directoryFile = new File(directoryFileName);
                               ^
  symbol:   variable directoryFileName
  location: class Directory
Directory.java:17: error: cannot find symbol
                           directoryFileName);
                           ^
  symbol:   variable directoryFileName
  location: class Directory
Directory.java:26: error: incompatible types: unexpected return value
            return true;
                   ^
Directory.java:28: error: incompatible types: unexpected return value
            return false;
                   ^
Directory.java:31: error: variable name is already defined in method main(String[])
   public boolean add(String name) {
                             ^
Directory.java:33: error: incompatible types: unexpected return value
         return false;
                ^
Directory.java:36: error: incompatible types: unexpected return value
            return false;
                   ^
Directory.java:39: error: incompatible types: unexpected return value
            return true;
                   ^
Directory.java:43: error: variable name is already defined in method main(String[])
   public boolean delete(String name) {
                                ^
Directory.java:47: error: incompatible types: unexpected return value
            return true;
                   ^
Directory.java:50: error: incompatible types: unexpected return value
            return false;
                   ^
Directory.java:58: error: cannot find symbol
         directoryDataOut = new PrintStream(directoryFile);
         ^
  symbol:   variable directoryDataOut
  location: class Directory
Directory.java:69: error: cannot find symbol
            directoryDataOut.println(directory[i]);
            ^
  symbol:   variable directoryDataOut
  location: class Directory
Directory.java:70: error: cannot find symbol
         directoryDataOut.close();
         ^
  symbol:   variable directoryDataOut
  location: class Directory
35 errors

我做错了什么？

Answer 1

这一行有一个错误:

System.out.println("File is not found, exiting!", 
                       directoryFileName);

System.out.println() 仅接受一个参数。除此之外，如果您标记错误的位置将会很有帮助发生。