我需要能够比较文件的条目 - Java

Question

`导入java.io.BufferedReader；导入 java.io.FileReader；导入 java.io.IOException;

public class Dokimi {

private static String line;


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


{

    int x = 0;
    BufferedReader br = new BufferedReader(new FileReader("src/film.txt"));
    line = br.readLine();

    String[] filmline = new String [1000];

    while (line != null) {
        line = br.readLine();
        filmline[x] = line;
        x++;

    }
    br.close();

    for (int i = 0; i<x; i++) // after many tries the last change I made is this. This is the testing class.
    {

        String [] arr = filmline[i].split(": ");


        if ( i == x-1) // I know it isn't the best, maybe not even good but I tried many things and had nothing to lose.

        {

            for ( String ss : arr) {

                   String test = ss;
                    if (test.equals("Dancing With The Dogs "))
                    {
                        System.out.println("gotcha!");

                    }

                }

        }
    }






}

}`因此，我有一个包含一些电影属性的文本文件。例如：

"film id :  1  film title :   Pirates Of Hawai  film category :   action ,      comedy   film description :  A pirate from Hawai drinks rum and goes on an adventure to find more rum."

（一行中的每个条目）并且每次用户尝试添加新条目时，我都必须确保该电影尚未在文件中。我尝试了 slpit 方法（通过使用 ":" 和擦除 "film id" 等）和 StringTokenizer 但它只在一个上工作并由我指定行，而不是在循环中以便它可以读取整个文件。

Answer 1

不要使用 StringTokenizer，它是遗留的，出于维护原因应该得到支持，但不会在新代码中实现。

考虑到标记每次都不同，您可能希望运行遍历字符串并在这里和那里使用子字符串，也就是说，假设每行包含相同的标记。

或者，更改您的输入：

"1*Pirates Of Hawaiaction , comedyA pirate from Hawai drinks rum and goes on an adventure to find more rum."

这样所有的token都是一样的，你就可以使用split方法了

Answer 2

根据here

稍微更改您的行以添加“：”：

"film id :  1 : film title :   Pirates Of Hawai : film category :   action ,      comedy :  film description :  A pirate from Hawai drinks rum and goes on an adventure to find more rum."

你可以试试这个方法并与你的比较：（在添加之前使用existsfilm验证它是否已经存在）

 public void showAllFilms(){
    ArrayList<String[]> films = getFilms();
    for(String[] film : films){
        System.out.println("id "+film[0]+"\ntitle "+film[1]);
    }
 }

 public existsFilm(String filmName){
     ArrayList<String[]> films = getFilms();
     for(String[] film : films){
         if(film[1].equals(filmName)){
           return true;
         }
     }
     return false;
 }

 public ArrayList<String[]> getFilms(){
    ArrayList<String[]> filmList = new ArrayList();
    int lineRead = 0;
    try{
        File file = new File("yourfile.txt");
        BufferedReader br = new BufferedReader(new FileReader(file)));
        String line;
        while ((line = br.readLine()) != null) {
           String[] data = line.split(":");
           if(data.length > 0){
               filmList.add(new String[]{data[1],data[3],data[5],data[7]});
           }
           lineRead++;
        }
    }catch(Exception ex){
        System.out.println("Error reading line "+lineRead);
        ex.printStackTrace(); //very ugly using this (common is logging it)
    }
    return filmList;
 }

我需要能够比较文件的条目 - Java

I need to be able to compare entries of a file - Java

java

compare

file