Java Swing仅将文件中的唯一行读入JtextArea

Question

Hello I am developing a swing application that reads contents from the text file and adds them to the JTextArea . I am able to read the file contents using the textarea.read() method

But the problem is the text file contains many duplicates which are unnecessary and need to be discarded.

Here is the code for reading:

private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         

BufferedReader reader = new BufferedReader(new FileReader(new File("D:/abc.txt")));          
jTextArea1.read(reader, "D:/abc.txt");

}

I've seen people suggesting the usage of LinkedHashSet , but I don't know how to use it in this context.

I need a solution that can read only unique lines from the text file and put it into the jTextArea .

Answer 1

I need a solution that can read only unique lines from the text file and put it into the jTextArea. - I think that the better solution is to read all the lines of the input file, not only those which are unique. It will be easier to do. You could create a while loop that reads each line of the input file, assign this line to the String variable and add this line to the LinkedHashSet<String> yourSet declared outside of this loop. You can add these lines (Strings) to yourSet with the method yourSet.add(String yourString) . After that you could iterate over your set and send each String line to yourJTextArea :

for(String s : yourSet) {
    yourJTextArea.append(s + "\n" );
}

Answer 2

You should read the file line by line using .readLine() and add the line to a HashSet Object, sets only allow unique elements. Once you have read the entire file and added them to the set you can just add the String to the textarea

Answer 3

Set is really good solution. In this context read file from new line in.nextLine() store value in String str = new String(value) and then set.add(str) After fill you textArea with values from Set