Mein kleines Wörterbuch

[Dexter1997]

Ich habe als kleine Übung ein textuelles Wortverwaltungsprogramm geschrieben. Vorschläge, was man wie verbessern könnte sind gerne gesehen Über jeden gemeldeten Fehler bin ich ebenfalls dankbar!

Ich erläutere mal kurz die Befehle:
help - ein Hilfetext wird angezeigt
show <argument> - Wörter werden angezeigt, mit Eingabe von "*" werden alle Wörter bzw Zeilen angezeigt
add <argument> - Zeile wird hinzugefügt
del <argument> - Wörter werden gelöscht
save - Wörter werden auf Festplatte gespeichert
exit - Programm wird geschlossen

Dictionary.java

import java.io.File;
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.FileNotFoundException;

public class Dictionary
{
    private String[] words;
    private File file;

    public Dictionary()
    {

        words = new String[1000];
        file = new File("words.txt");

        int i = 0;
        if (file.exists())
        {
            try
            {
                FileReader file_reader = new FileReader("words.txt");
                BufferedReader buffered_reader = new BufferedReader(file_reader);

                String word;
                while((word = buffered_reader.readLine()) != null)
                {
                    words[i] = word;
                    i++;
                }

                buffered_reader.close();
            }
            catch(FileNotFoundException e)
            {
                e.printStackTrace();
            }
            catch(IOException e)
            {
                e.printStackTrace();
            }
        }
        else
        {
            try
            {
                file.createNewFile();
            }
            catch(IOException e)
            {
                e.printStackTrace();
            }
        }

        for(;i < 1000; i++)
            words[i] = "";
    }

    public void show_words(String filter)
    {
        if (filter.equals("*"))
        {
            for(String word : words)
            {
                if(word.equals(""))
                {
                    break;
                }
                else if(!(word.equals("<[d]>")))
                {
                    System.out.println(word);
                }
            }
        }
        else
        {
            for(String word : words)
            {
                if(word.toLowerCase().contains(filter.toLowerCase()))
                {
                    System.out.println(word);
                }
                else if(word.equals(""))
                {
                    break;
                }
            }
        }
    }

    public void add_word(String word)
    {
        for(int i = 0; i < words.length; i++)
        {
            if (words[i].equals("") || word.equals("<[d]>"))
            {
                words[i] = word;
                break;
            }
        }
    }

    public void del_words(String string)
    {
        for(int i = 0; i < words.length; i++)
        {
            if (words[i].contains(string))
            {
                System.out.println("\"" + words[i] + "\" deleted");
                words[i] = "<[d]>";
            }
        }      
    }

    public void save_words()
    {
        try
        {
            FileWriter file_writer = new FileWriter("words.txt");
            BufferedWriter buffered_writer = new BufferedWriter(file_writer);
            int i = 0;
            while(words[i] != "")
            {
                if(!(words[i].equals("<[d]>")))
                {
                    buffered_writer.write(words[i]);
                    buffered_writer.newLine();
                }
                i++;
            }
            buffered_writer.close();
        }
        catch(IOException e)
        {
            e.printStackTrace();
        }
    }
}

Commander.java

import java.util.Scanner;

public class Commander
{
    private Dictionary dictionary;
    private Scanner input;

    public Commander()
    {
        input = new Scanner(System.in);
        dictionary = new Dictionary();
    }

    public void init()
    {
        while (true)
        {
            System.out.print("> ");
            String command = input.nextLine();

            if(command.equals("help"))
            {
                help();
            }
            else if(command.length() >= 4 && command.substring(0, 4).equals("show"))
            {
                dictionary.show_words(parse(command));
            }
            else if(command.length() >= 3 && command.substring(0, 3).equals("add"))
            {
                dictionary.add_word(parse(command));
            }
            else if(command.length() >= 3 && command.substring(0, 3).equals("del"))
            {
                dictionary.del_words(parse(command));
            }
            else if(command.equals("save"))
            {
                dictionary.save_words();
            }

            else if(command.equals("exit"))
            {
                dictionary.save_words();
                break;
            }
            else
            {
                System.out.println("invalid syntax");
            }
        }
    }

    private String parse(String input)
    {
        String parsed = input.substring(input.indexOf(' ') + 1, input.length());
        return parsed;
    }

    private void help()
    {

        System.out.println("help - no arguments    - shows information");
        System.out.println("save - no arguments    - writing changes on hard drive");
        System.out.println("show - <string> or <*> - shows words");
        System.out.println("add  - <string>        - adds word to dictionary");
        System.out.println("del  - <string>        - deletes entrys that contain string");
    }
}

Start.java

public class Start
{
    public static void main(String[] args)
    {
        Commander commander = new Commander();
        commander.init();
    }
}

Die Datei "words.txt" könnte so aussehen:

Hallo - hello
Apfel - apple
Zeichenfolge - string
rot - red
gelb - yellow
neu - new
alt - old
Wie geht es dir? - How are you?
Insel - island
Welt - world