Question

我有以下创建和写入该文件的方法。

// Create the file and the PrintWriter that will write to the file

    private static PrintWriter createFile(String fileName){

        try{

            // Creates a File object that allows you to work with files on the hardrive

            File listOfNames = new File(fileName);


            PrintWriter infoToWrite = new PrintWriter(new BufferedWriter(
                    new FileWriter(listOfNames);
            return infoToWrite;
        }

        // You have to catch this when you call FileWriter

        catch(IOException e){

            System.out.println("An I/O Error Occurred");

            // Closes the program

            System.exit(0);

        }
        return null;

    }

该程序运行正常，即使我没有bufferedWriter and FileWriter如下所示。他们两个对象如何帮助改善写作过程？在这种情况下，我可以避免创建两个对象。

PrintWriter infoToWrite = new PrintWriter((listOfNames);

Answer 1

BufferedWriter

通常，Writer会立即将其输出发送到底层   字符或字节流。除非需要提示输出，否则它是   建议将BufferedWriter包装在任何write（）的Writer周围   操作可能很昂贵，例如FileWriters和OutputStreamWriters。

如果你一次写大块文本（比如整行）   那么你可能不会注意到差异。如果你有很多代码   但是，一次追加一个字符，一个BufferedWriter   会更有效率。

Answer 2

您可以参考API文档，您会发现不同之处：

BufferedWriter:Writes text to a character-output stream, buffering characters so as to provide for the efficient writing of single characters, arrays, and strings. 

FileWriter:Convenience class for writing character files. The constructors of this class assume that the default character encoding and the default byte-buffer size are acceptable. To specify these values yourself, construct an OutputStreamWriter on a FileOutputStream.

如果你想创建一个文件，FileWriter会更好。

使用printWriter以两种方式用Java写入文件，哪一个更好，为什么？

2 个答案: