Java的字符读写类CharArrayReader和CharArrayWriter使用示例

CharArrayReader
CharArrayReader 是字符数组输入流。它和ByteArrayInputStream类似，只不过ByteArrayInputStream是字节数组输入流，而CharArray是字符数组输入流。CharArrayReader 是用于读取字符数组，它继承于Reader。操作的数据是以字符为单位！
CharArrayReader 函数列表：

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)

示例代码:
关于CharArrayReader中API的详细用法，参考示例代码(CharArrayReaderTest.java)：

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

public class CharArrayReaderTest {

  private static final int LEN = 5;
  // 对应英文字母“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测试函数
   */
  private static void tesCharArrayReader() {
    try {
      // 创建CharArrayReader字符流，内容是ArrayLetters数组
      CharArrayReader car = new CharArrayReader(ArrayLetters);

      // 从字符数组流中读取5个字符
      for (int i=0; i 
 

运行结果：

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

CharArrayWriter
CharArrayReader 用于写入数据符，它继承于Writer。操作的数据是以字符为单位！
CharArrayWriter 函数列表

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)

示例代码：
关于CharArrayWriter中API的详细用法，参考示例代码(CharArrayWriterTest.java)：

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

public class CharArrayWriterTest {

  private static final int LEN = 5;
  // 对应英文字母“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测试函数
   */
  private static void tesCharArrayWriter() {
    try {
      // 创建CharArrayWriter字符流
      CharArrayWriter caw = new CharArrayWriter();

      // 写入“A”个字符
      caw.write('A');
      // 写入字符串“BC”个字符
      caw.write("BC");
      //System.out.printf("caw=%s\n", caw);
      // 将ArrayLetters数组中从“3”开始的后5个字符(defgh)写入到caw中。
      caw.write(ArrayLetters, 3, 5);
      //System.out.printf("caw=%s\n", caw);

      // (01) 写入字符0
      // (02) 然后接着写入“123456789”
      // (03) 再接着写入ArrayLetters中第8-12个字符(ijkl)
      caw.append('0').append("123456789").append(String.valueOf(ArrayLetters), 8, 12);

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

      // 计算长度
      int size = caw.size();
      System.out.printf("size=%s\n", size);

      // 转换成byte[]数组
      char[] buf = caw.toCharArray();
      System.out.printf("buf=%s\n", String.valueOf(buf));

      // 将caw写入到另一个输出流中
      CharArrayWriter caw2 = new CharArrayWriter();
      caw.writeTo(caw2);
      System.out.printf("caw2=%s\n", caw2);
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

运行结果：

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