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<LEN; i++) { // 若能继续读取下一个字符,则读取下一个字符 if (car.ready() == true) { // 读取“字符流的下一个字符” char tmp = (char)car.read(); System.out.printf("%d : %c\n", i, tmp); } } // 若“该字符流”不支持标记功能,则直接退出 if (!car.markSupported()) { System.out.println("make not supported!"); return ; } // 标记“字符流中下一个被读取的位置”。即--标记“f”,因为因为前面已经读取了5个字符,所以下一个被读取的位置是第6个字符” // (01), CharArrayReader类的mark(0)函数中的“参数0”是没有实际意义的。 // (02), mark()与reset()是配套的,reset()会将“字符流中下一个被读取的位置”重置为“mark()中所保存的位置” car.mark(0); // 跳过5个字符。跳过5个字符后,字符流中下一个被读取的值应该是“k”。 car.skip(5); // 从字符流中读取5个数据。即读取“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,将“字符流中下一个被读取的位置”重置到“mark()所标记的位置”,即f。 car.reset(); // 从“重置后的字符流”中读取5个字符到buf中。即读取“fghij” car.read(buf, 0, LEN); System.out.printf("buf=%s\n", String.valueOf(buf)); } catch (IOException e) { e.printStackTrace(); } }}
运行结果:
0 : a1 : b2 : c3 : d4 : ebuf=klmnobuf=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=ABCdefgh0123456789ijklsize=22buf=ABCdefgh0123456789ijklcaw2=ABCdefgh0123456789ijkl