java - BufferedWriter 行分隔符变为双行分隔符

Question

BufferedWriter bw = new BufferedWriter(new FileWriter("test.csv", true));
bw.append(System.lineSeparator());
bw.append("Text after writing"));

上面的代码将产生以下结果:

Text already in file before writing

Text after writing

没有System.lineSeparator()，它将变成:

Text already in file before writingText after writing 

我想要的是:

Text already in file before writing
Text after writing

我也试过\n 和 bw.newLine() ，但都给出了相同的结果。为什么会留下 2 行，如何避免？

Answer 1

刚刚尝试了您的代码，它按预期工作。

代码:

try (BufferedWriter bw = new BufferedWriter(new FileWriter("test.csv", true))) {

    bw.append("Text after writing");
    bw.append(System.lineSeparator());

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

test.csv 之前:

1. Text already in file before writing

test.csv 之后:

1. Text already in file before writing
2. Text after writing

可能您正在编辑的文件已经以新行结尾。您可以考虑在附加之前检查它。

注意:使用了 try-with-resource为了简化代码。

注意:测试于:jre1.8.0_77，Win7(x64)