使用 BufferedReader 和 ScheduledExecutor 记录日志

Question

我目前正在学习我的 JAVA SE OCP 认证，并尝试学习一些东西。

我目前正在阅读 IO 章节。我正在尝试将 ScheduledExecutor 与 BufferedWriter

结合起来

ScheduledExecutorService service = null;
try (BufferedWriter bw = new BufferedWriter(new FileWriter(testFile))) {
    service = Executors.newSingleThreadScheduledExecutor();
    service.scheduleAtFixedRate(() -> {
        try {
            bw.write("Curr Time: " + LocalTime.now());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }, 1, 1, TimeUnit.SECONDS);
}

我希望每秒在我的 TestFile 上的一个新行上写入 LocalTime，但是出现了这个 IOException：

java.io.IOException: Stream closed
at java.io.BufferedWriter.ensureOpen(BufferedWriter.java:116)
at java.io.BufferedWriter.write(BufferedWriter.java:221)
at java.io.Writer.write(Writer.java:157)
at Worksheet.lambda$main[=11=](Worksheet.java:56)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) {...}

Answer 1

试试：

ScheduledExecutorService service = null;
    service = Executors.newSingleThreadScheduledExecutor();
    try {
        BufferedWriter bw = new BufferedWriter(new FileWriter(testFile, true));
        service.scheduleAtFixedRate(() -> {
            try {
                bw.write("Curr Time: " + LocalTime.now() + "\n");
                bw.flush();
            } catch (IOException ioe) {
                ioe.printStackTrace();
            }
        }, 1, 1, TimeUnit.SECONDS);

    } catch (IOException ioe) {
        ioe.printStackTrace();
    }

FileWriter 中的 true 参数会将每个新行附加到现有文件，而不是创建新文件。

使用 BufferedReader 和 ScheduledExecutor 记录日志

Log using BufferedReader and ScheduledExecutor

java

multithreading

threadpool