PrintWriter 构造函数

Question

我在下面列出了 PrintWriter class.
的 8 个构造函数 PrintWriter(File file), PrintWriter(File file, String csn), PrintWriter(OutputStream out), PrintWriter(OutputStream out, boolean autoFlush), PrintWriter(String fileName), PrintWriter(String fileName, String csn), PrintWriter(Writer out), PrintWriter(Writer out, boolean autoFlush).

问题：

如果没有采用 PrintStream 的 PrintWriter 构造器，那我们怎么能像我下面写的那样写一个语句呢？

如果没有采用 BufferedWriter 的 PrintWriter 构造器，那我们怎么能像我下面写的那样写一个语句？

      PrintWriter writer1 = new PrintWriter(System.out);

      PrintWriter writer2;
      writer2 = new PrintWriter(new BufferedWriter(new FileWriter(new File(outdir, reportFileName))));

提前致谢。

Answer 1

这是可能的，因为 PrintStream 继承自 FilterOutputStream，后者又继承自 OutputStream。

A BufferedWriter 继承自 Writer。

Writer 和 OutputStream 是 PrintWriter constructors. The big topic, what we are talking about here, is inheritance. There is a good post 中可能的变量。

PrintWriter 构造函数

PrintWriter constructors

java

printwriter