chararraywriterdemo.java

来自「java2参考大全上的例子的源码和自己的理解.」· Java 代码 · 共 55 行

package chararraywriter;

/**
 CharArrayWriter  实现了以数组作为目标的输出流。CharArrayWriter  有两个构造函数：
 CharArrayWriter( )
 CharArrayWriter(int numChars)
 第一种形式，创建了一个默认长度的缓冲器。第二种形式，缓冲器长度由numChars指
 定。缓冲器保存在CharArrayWriter的buf  成员中。缓冲器大小在需要的情况下可以自动增
 长。缓冲器保持的字符数包含在CharArrayWriter的count  成员中。buf  和count  都是受保护
 的域。
 下面的例子阐述了CharArrayWriter，我们继续使用前面显示的ByteArrayOutputStream
 例子中演示的程序。它的输出与以前的例子输出相同：

 Buffer as a string
This should end up in the array
Into array
This should end up in the array
To a FileWriter()
Doing a reset
XXX
 */

// Demonstrate CharArrayWriter.
import java.io.*;

class CharArrayWriterDemo {
  public static void main(String args[]) throws IOException {
    CharArrayWriter f = new CharArrayWriter();
    String s = "This should end up in the array";
    char buf[] = new char[s.length()];

    s.getChars(0, s.length(), buf, 0);
    f.write(buf);
    System.out.println("Buffer as a string");
    System.out.println(f.toString());
    System.out.println("Into array");

    char c[] = f.toCharArray();
    for (int i = 0; i < c.length; i++) {
      System.out.print(c[i]);
    }

    System.out.println("\nTo a FileWriter()");
    FileWriter f2 = new FileWriter("test.txt");
    f.writeTo(f2);
    f2.close();
    System.out.println("Doing a reset");
    f.reset();
    for (int i = 0; i < 3; i++) {
      f.write('X');
    }
    System.out.println(f.toString());
  }
}