java io學習（十七） CharArrayReader(字元數組輸入資料流)

CharArrayReader 介紹

CharArrayReader 是字元數組輸入資料流。它和ByteArrayInputStream類似，只不過ByteArrayInputStream是位元組數組輸入資料流，而CharArray是字元數組輸入資料流。CharArrayReader 是用於讀取字元數組，它繼承於Reader。操作的資料是以字元為單位！

CharArrayReader 函數列表

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)

Reader和CharArrayReader源碼分析

Reader是CharArrayReader的父類，我們先看看Reader的源碼，然後再學CharArrayReader的源碼。

1. Reader源碼分析(基於jdk1.7.40)

package java.io;     public abstract class Reader implements Readable, Closeable {         protected Object lock;         protected Reader() {        this.lock = this;    }         protected Reader(Object lock) {        if (lock == null) {            throw new NullPointerException();        }        this.lock = lock;    }         public int read(java.nio.CharBuffer target) throws IOException {        int len = target.remaining();        char[] cbuf = new char[len];        int n = read(cbuf, 0, len);        if (n > 0)            target.put(cbuf, 0, n);        return n;    }         public int read() throws IOException {        char cb[] = new char[1];        if (read(cb, 0, 1) == -1)            return -1;        else            return cb[0];    }         public int read(char cbuf[]) throws IOException {        return read(cbuf, 0, cbuf.length);    }         abstract public int read(char cbuf[], int off, int len) throws IOException;         private static final int maxSkipBufferSize = 8192;         private char skipBuffer[] = null;         public long skip(long n) throws IOException {        if (n < 0L)            throw new IllegalArgumentException("skip value is negative");        int nn = (int) Math.min(n, maxSkipBufferSize);        synchronized (lock) {            if ((skipBuffer == null) || (skipBuffer.length < nn))                skipBuffer = new char[nn];            long r = n;            while (r > 0) {                int nc = read(skipBuffer, 0, (int)Math.min(r, nn));                if (nc == -1)                    break;                r -= nc;            }            return n - r;        }    }         public boolean ready() throws IOException {        return false;    }         public boolean markSupported() {        return false;    }         public void mark(int readAheadLimit) throws IOException {        throw new IOException("mark() not supported");    }         public void reset() throws IOException {        throw new IOException("reset() not supported");    }          abstract public void close() throws IOException;}