如何使用缓冲阅读器java从txt文件中删除行[重复]

Question

我需要从 txt 文件 a 中删除行

FileReader fr= new FileReader("Name3.txt");

BufferedReader br = new BufferedReader(fr);

String str = br.readLine();

br.close();

我不知道代码的继续。

Answer 1

您可以读取所有行并将它们存储在列表中。在存储所有行时，假设您知道要删除的行，只需检查您不想存储的行，然后跳过它们。然后将列表内容写入文件。

    //This is the file you are reading from/writing to
    File file = new File("file.txt");
    //Creates a reader for the file
    BufferedReader br = new BufferedReader(new FileReader(file));
    String line = "";

    //This is your buffer, where you are writing all your lines to
    List<String> fileContents = new ArrayList<String>();

    //loop through each line
    while ((line = br.readLine()) != null) {
        //if the line we're on contains the text we don't want to add, skip it
        if (line.contains("TEXT_TO_IGNORE")) {
            //skip
            continue;
        }
        //if we get here, we assume that we want the text, so add it
        fileContents.add(line);
    }

    //close our reader so we can re-use the file
    br.close();

    //create a writer
    BufferedWriter bw = new BufferedWriter(new FileWriter(file));

    //loop through our buffer
    for (String s : fileContents) {
        //write the line to our file
        bw.write(s);
        bw.newLine();
    }

    //close the writer
    bw.close();