Java用定界符读取文本文件并将其推入数组

Question

I am reading a file which has a delimiter between elements. I am trying to put each element into a new index of an array. This does not seem to work properly, everything seems to end up on one index of the array. Below is a sample text file and my code.

Textfile

%User  %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel%James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel %James %Fields %Will Smith %sBel

Code

final InputStream i = getResources().openRawResource(R.raw.users);
final Scanner s = new Scanner(i);
try
{
    while (s.hasNextLine())
    {
        String d = s.nextLine();
        String test;

        test = values[1];           
        userTextArea.append(test);
        test = "";
    }
}

Answer 1

final InputStream i = getResources().openRawResource(R.raw.users);
final Scanner s = new Scanner(i);
try
{
     while (s.hasNextLine())
    {
        String d = s.nextLine();
        StringTokenizer st = new StringTokenizer(d,"%");
        String[] myStringArray = new String[st.countTokens()]

        int index = 0;
        while(st.hasMoreTokens()) {
            myStringArray[index] = st.nextElement();
            index ++;
        }
    }
} catch (Exception e) {
....
}

Answer 2

You have to use the split function.

String tmp = "%hallo %world";
String [] strArray = tmp.split("%");
System.out.print(strArray[0]); //prints hallo 

Answer 3

An array is a container object that holds a fixed number of values stored in unique indexes (positions).

Causes

everything seems to end up on one index of the array

It will do, for two reasons:

1. The file you are reading in has no new-line characters. It will therefore assign all of the file contents to the variable " d " when you call nextLine() .

     String d = s.nextLine(); 

   To clarify, at this point in your program, " d " holds your whole text file.

2. Even if it did have new-line characters, you still wouldn't be reading anything into an array. After assigning the string to the variable " d ". You are not doing anything with it.

Suggestions

One way of doing this would be to:

• Read the file as you are, as a single line and then use the String split() function to split elements, this function returns an array so you need to assign it to a String[] array variable. Omit the while loop as you only need to read a single line. After this, loop through the string array and append the values to the text area:

    String d = s.nextLine(); String[] values = d.split("%"); for(String value: values) { userTextArea.append(value.trim()); } 

  When appending, don't forget to trim the string because your file contains spaces between elements. The String trim() function will remove these.