java - 为什么 BufferedWriter write 方法会产生不同的结果？

Question

我不明白为什么这两种实现会产生不同的结果？

具有预期结果的方法:

    private void writeToFile(WorkoutLog log){
        try {
        BufferedWriter out = new BufferedWriter(new FileWriter("src/exercise/textfile2.txt", true));

        out.write(log.name.toString() + ", " + log.type + ", " + log.duration + ", " + log.caloriesburned + "\n");
        out.close();
    }catch (IOException e) {  
        System.out.println("error writing record to text file " + e );
    }
}

数据文件结果

吉姆，1, 123, 246

迈克，3、12、24

吉姆，4, 50, 100

乔尼，5, 40, 80

结果意想不到的方法:

    private void writeToFile2(WorkoutLog log){
    try {
        BufferedWriter out = new BufferedWriter(new FileWriter("src/exercise/textfile2.txt", true));

        out.write(log.name.toString());
        out.write(", ");
        out.write(log.type);
        out.write(",");
        out.write(log.duration);
        out.write(",");
        out.write(log.caloriesburned);
        out.write("\n");
        out.close();
    }catch (IOException e) {  
        System.out.println("error writing record to text file " + e );
    }
}

数据文件结果

乔、、、@

弗雷德,,{,ö

为什么将 out.write 语句分成单独的行会导致输出产生奇怪的结果？每个方法都会传递一个带有对象的数组引用，该对象存储要写入的字符串、短、短短数据类型的结果。

Answer 1

我假设 log.type、log.duration 和 log.caloriesburned 是 int 值，其中意味着您正在调用 BufferedWriter.write(int)重载。这只写了一个字符。我怀疑你只需要:

out.write(log.name.toString());
out.write(", ");
out.write(String.valueOf(log.type));
out.write(",");
out.write(String.valueOf(log.duration));
out.write(",");
out.write(String.valueOf(log.caloriesburned));
out.write("\n");

请注意，您应该在 finally block 中关闭编写器，这样即使出现异常，它也会关闭。