CharArrayReader(char[] buf)
CharArrayReader(char[] buf, int offset, int length)

void   close()
void   mark(int readLimit)
boolean  markSupported()
int    read()
int    read(char[] buffer, int offset, int len)
boolean  ready()
void   reset()
long   skip(long charCount)

import java.io.CharArrayReader;
import java.io.CharArrayWriter;
import java.io.IOException;

public class CharArrayReaderTest {

  private static final int LEN = 5;
  // 對應英文字母“abcdefghijklmnopqrstuvwxyz”
  private static final char[] ArrayLetters = new char[] {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};

  public static void main(String[] args) {
    tesCharArrayReader() ;
  }

  /**
   * CharArrayReader的API測試函數(shù)
   */
  private static void tesCharArrayReader() {
    try {
      // 創(chuàng)建CharArrayReader字符流，內容是ArrayLetters數(shù)組
      CharArrayReader car = new CharArrayReader(ArrayLetters);

      // 從字符數(shù)組流中讀取5個字符
      for (int i=0; i<LEN; i++) {
        // 若能繼續(xù)讀取下一個字符，則讀取下一個字符
        if (car.ready() == true) {
          // 讀取“字符流的下一個字符”
          char tmp = (char)car.read();
          System.out.printf("%d : %c\n", i, tmp);
        }
      }

      // 若“該字符流”不支持標記功能，則直接退出
      if (!car.markSupported()) {
        System.out.println("make not supported!");
        return ;
      }

      // 標記“字符流中下一個被讀取的位置”。即--標記“f”，因為因為前面已經讀取了5個字符，所以下一個被讀取的位置是第6個字符”
      // (01), CharArrayReader類的mark(0)函數(shù)中的“參數(shù)0”是沒有實際意義的。
      // (02), mark()與reset()是配套的，reset()會將“字符流中下一個被讀取的位置”重置為“mark()中所保存的位置”
      car.mark(0);

      // 跳過5個字符。跳過5個字符后，字符流中下一個被讀取的值應該是“k”。
      car.skip(5);

      // 從字符流中讀取5個數(shù)據(jù)。即讀取“klmno”
      char[] buf = new char[LEN];
      car.read(buf, 0, LEN);
      System.out.printf("buf=%s\n", String.valueOf(buf));

      // 重置“字符流”：即，將“字符流中下一個被讀取的位置”重置到“mark()所標記的位置”，即f。
      car.reset();
      // 從“重置后的字符流”中讀取5個字符到buf中。即讀取“fghij”
      car.read(buf, 0, LEN);
      System.out.printf("buf=%s\n", String.valueOf(buf));
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

0 : a
1 : b
2 : c
3 : d
4 : e
buf=klmno
buf=fghij

CharArrayWriter()
CharArrayWriter(int initialSize)

CharArrayWriter   append(CharSequence csq, int start, int end)
CharArrayWriter   append(char c)
CharArrayWriter   append(CharSequence csq)
void   close()
void   flush()
void   reset()
int   size()
char[]   toCharArray()
String   toString()
void   write(char[] buffer, int offset, int len)
void   write(int oneChar)
void   write(String str, int offset, int count)
void   writeTo(Writer out)

import java.io.CharArrayReader;
import java.io.CharArrayWriter;
import java.io.IOException;

public class CharArrayWriterTest {

  private static final int LEN = 5;
  // 對應英文字母“abcdefghijklmnopqrstuvwxyz”
  private static final char[] ArrayLetters = new char[] {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'};

  public static void main(String[] args) {

    tesCharArrayWriter() ;
  }

  /**
   * CharArrayWriter的API測試函數(shù)
   */
  private static void tesCharArrayWriter() {
    try {
      // 創(chuàng)建CharArrayWriter字符流
      CharArrayWriter caw = new CharArrayWriter();

      // 寫入“A”個字符
      caw.write('A');
      // 寫入字符串“BC”個字符
      caw.write("BC");
      //System.out.printf("caw=%s\n", caw);
      // 將ArrayLetters數(shù)組中從“3”開始的后5個字符(defgh)寫入到caw中。
      caw.write(ArrayLetters, 3, 5);
      //System.out.printf("caw=%s\n", caw);

      // (01) 寫入字符0
      // (02) 然后接著寫入“123456789”
      // (03) 再接著寫入ArrayLetters中第8-12個字符(ijkl)
      caw.append('0').append("123456789").append(String.valueOf(ArrayLetters), 8, 12);

      System.out.printf("caw=%s\n", caw);

      // 計算長度
      int size = caw.size();
      System.out.printf("size=%s\n", size);

      // 轉換成byte[]數(shù)組
      char[] buf = caw.toCharArray();
      System.out.printf("buf=%s\n", String.valueOf(buf));

      // 將caw寫入到另一個輸出流中
      CharArrayWriter caw2 = new CharArrayWriter();
      caw.writeTo(caw2);
      System.out.printf("caw2=%s\n", caw2);
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

caw=ABCdefgh0123456789ijkl
size=22
buf=ABCdefgh0123456789ijkl
caw2=ABCdefgh0123456789ijkl