Question

Please help me to troubleshoot this problem.

A have an input file ‘Trial.txt’ with content “Thanh Le”.

Here is the function I used in an attempt to read from the file:

    public char[] importSeq(){
    File file = new File("G:\\trial.txt");

    char temp_seq[] = new char[100];

    try{
    FileInputStream fis = new FileInputStream(file);
    BufferedInputStream bis = new BufferedInputStream(fis);
    DataInputStream dis = new DataInputStream(bis);

    int i = 0;

    //Try to read all character till the end of file
    while(dis.available() != 0){
        temp_seq[i]=dis.readChar();
        i++;
    }
    System.out.println(" imported");
    } catch (FileNotFoundException e){
        e.printStackTrace();
    } catch (IOException e){
        e.printStackTrace();
    }

    return temp_seq;
}

And the main function:

public static void main(String[] args) {

    Sequence s1 = new Sequence();

    char result[];

    result = s1.importSeq();

    int i = 0;
    while(result[i] != 0){
        System.out.println(result[i]);
        i++;
    }
}

And this is the output.

run:

 imported
瑨
慮
栠
汥
BUILD SUCCESSFUL (total time: 0 seconds)

Answer 1

That’s honestly said a pretty clumsy way to read a text file into a char[].

Here’s a better example, assuming that the text file contains only ASCII characters.

File file = new File("G:/trial.txt");
char[] content = new char[(int) file.length()];
Reader reader = null;

try {
    reader = new FileReader(file);
    reader.read(content);
} finally {
    if (reader != null) try { reader.close(); } catch (IOException ignore) {}
}

return content;

And then to print the char[], just do:

System.out.println(content);

Note that InputStream#available() doesn’t necessarily do what you’re expecting.

See also:

• Java IO tutorial