用于判断字符结尾的输入流类

最新推荐文章于 2022-06-11 13:46:05 发布

原创最新推荐文章于 2022-06-11 13:46:05 发布 · 1k 阅读

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文章标签：

#buffer #character #import #byte #class #null

此博客展示了Java中CharTerminatedInputStream类的实现代码。该类继承自InputStream，用于处理以特定字符数组终止的输入流。代码包含构造函数、重置方法和读取方法等，对输入流的读取和终止条件进行了详细处理。

import java.io.IOException;
import java.io.InputStream;

public class CharTerminatedInputStream extends InputStream {

private InputStream in;

private int match[];

private int buffer[];

private int pos = 0;

private boolean endFound = false;

public CharTerminatedInputStream(InputStream in, byte[] terminator) {
    if (terminator == null) {
      throw new IllegalArgumentException("The terminating character array cannot be null.");
    }
    if (terminator.length == 0) {
      throw new IllegalArgumentException("The terminating character array cannot be of zero length.");
    }
    match = new int[terminator.length];
    buffer = new int[terminator.length];
    for (int i = 0; i < terminator.length; i++) {
      match[i] = (int) terminator[i];
      buffer[i] = (int) terminator[i];
    }
    this.in = in;
}

public synchronized void reset() {
endFound = false;
pos = 0;
}

public int read() throws IOException {

    if (endFound) {
      return -1;
    }

    if (pos == 0) {
      int b = in.read();
      if (b == -1) {
        endFound = true;
        return -1;
      }
      if (b != match[0]) {
        return b;
      }
      buffer[0] = b;
      pos++;
    } else {
      if (buffer[0] != match[0]) {
        return topChar();
      }
    }
    for (int i = 0; i < match.length; i++) {
      if (i >= pos) {
        int b = in.read();
        if (b == -1) {
          return topChar();
        }
        buffer[pos] = b;
        pos++;
      }
      if (buffer[i] != match[i]) {
        return topChar();
      }
    }
    endFound = true;
    return -1;
}

private int topChar() {
    int b = buffer[0];
    if (pos > 1) {
      System.arraycopy(buffer, 1, buffer, 0, pos - 1);
    }
    pos--;
    return b;
}
}