使用FileReader只显示最后一行文本文件?

时间:2011-04-10 17:39:41

标签: java line jtextarea text-files filereader

我正在尝试显示我在GUI中创建的JTextArea中的文本文件中的信息。我已经想出如何从文件中获取信息到JTextArea,但它只抓取文件的最后一行。我需要显示所有的行。我不断改变循环,但无法弄清楚这个。任何帮助将不胜感激。以下是我的代码:

public TextArea() {
    initComponents();


    try {
        FileReader one = new FileReader ("info.txt");
        BufferedReader buf = new BufferedReader(one);

        String line = "";
        StringTokenizer st = null;
        int lineNumber = 0, tokenNumber = 0;
        //textArea.setText(line);

        while ((line = buf.readLine()) != null) {
            lineNumber++;

            //break comma separated line using ","
            st = new StringTokenizer(line, ",");

            while (st.hasMoreTokens()) {
                //display csv values
                tokenNumber++;
                line = ("Title: " + st.nextToken()
                        + "\n" + "Make:" + st.nextToken()
                        + "\n" + "Model:" + st.nextToken()
                        + "\n" + "Year:" + st.nextToken()
                        + "\n" + "Price:" + st.nextToken()
                        + "\n" + "Notes:" + st.nextToken()
                        + "\n" + "Details:" + st.nextToken()
                        + "\n");

                textArea.setText(line);
            }

            //reset token number
            tokenNumber = 0;
            //textArea.setText(line);
        }

    } catch (FileNotFoundException e) {
        JOptionPane.showMessageDialog(this, "File not found");
    } catch (IOException e){
        JOptionPane.showMessageDialog(this, "Data not read");
    }

3 个答案:

答案 0 :(得分:1)

看看你的代码:

while (st.hasMoreTokens()) {
            //display csv values
            tokenNumber++;
            line = ("Title: " + st.nextToken()
                    + "\n" + "Make:" + st.nextToken()
                    + "\n" + "Model:" + st.nextToken()
                    + "\n" + "Year:" + st.nextToken()
                    + "\n" + "Price:" + st.nextToken()
                    + "\n" + "Notes:" + st.nextToken()
                    + "\n" + "Details:" + st.nextToken()
                    + "\n");

            textArea.setText(line);
        }

每次找到新令牌时,都会将textarea val设置为找到的最后一个令牌。 所以显然文本区域只显示最后一行。 您可以尝试以下方式:

textArea.setText(textArea.getText() + line);

答案 1 :(得分:0)

我认为你正在重写线变量。

line+=...

连接,然后设置在循环外连接的整行的值。

答案 2 :(得分:0)

while (st.hasMoreTokens()) {
            //display csv values
            tokenNumber++;
            line = line +"\n"+("Title: " + st.nextToken()
                    + "\n" + "Make:" + st.nextToken()
                    + "\n" + "Model:" + st.nextToken()
                    + "\n" + "Year:" + st.nextToken()
                    + "\n" + "Price:" + st.nextToken()
                    + "\n" + "Notes:" + st.nextToken()
                    + "\n" + "Details:" + st.nextToken()
                    + "\n");


        }
 textArea.setText(line);