在Java中编辑文本文件

Question

I want add few strings to a text file in a particular location. I have used BufferedReader to read the text file. Then I added the string at the particular position and wrote the modified text to a new temp file using BufferedWriter .

Then I deleted the old file and renamed the temp file to old file name. This works sometimes and does not work sometimes. The delete() function sometimes does not delete the file. I have closed all the BufferedWriter 's, but the problem still occurs sometimes.

Code:

public boolean cart(String uname, String item) throws IOException {
    File file = new File("C:\\$$$$.tmp");
    if (!file.exists()) {
        file.createNewFile();
    }
    FileWriter fw = new FileWriter(file.getAbsoluteFile(), true);
    BufferedWriter bw = new BufferedWriter(fw);
    File fileop = new File("C:\\value.text");
    FileReader fr = new FileReader(fileop.getAbsoluteFile());
    BufferedReader br = new BufferedReader(fr);
    String line;
    while((line = br.readLine()) != null) {
        String val[] = line.split(",");
        if (val[0].equals(uname)) {
            String linenew = line + item + "&";
            bw.append(linenew);
            bw.newLine();
            bw.flush();
        } else {
            bw.append(line);
            bw.newLine();
            bw.flush();
        }
    }
    br.close();
    bw.close();
    fileop.delete();
    file.renameTo(fileop);
    return true;
 }

Answer 1

I found the answer by myself after spending one full day of searching..

Answer is:

It is enough to close the bufferedReader but also the fileReader..

fr.close(); should be inserted after br.close();