alphabetizer.java

软件体系结构 KWIC三种风格的java实现

package PipeKwic;

import java.io.CharArrayWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;


public class Alphabetizer extends Filter {

	public Alphabetizer(Pipe input, Pipe output) {
		super(input, output);
	}

	/**
	 * 
	 */
	@Override
	protected void transform() {
		List<String> lines = new ArrayList<String>();
		CharArrayWriter writer = new CharArrayWriter();
		try {
			int c = -1;
			while((c = input.read()) != -1) {
				writer.write(c);
		//		System.out.print((char) c);
				if(c == 10) {
					String curLine = writer.toString();
					lines.add(curLine);
					writer.reset();
				}
			}
			
			
			sort(lines);
			
			for(String s : lines) {
				output.write(s);
			}
			
			input.closeReader();
			output.closeWriter();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	private void sort(List<String> lines) { //堆排序
		int size = lines.size();

		for (int i = (size / 2 - 1); i >= 0; i--)
			siftDown(lines, i, size);

		for (int i = (size - 1); i >= 1; i--) {
			Object tmp = lines.get(0);
			lines.set(0, lines.get(i));
			lines.set(i, (String) tmp);
			siftDown(lines, 0, i);
		}
	}

	private void siftDown(List<String> lines, int root, int bottom) {
		int max_child = root * 2 + 1;

		while (max_child < bottom) {
			if ((max_child + 1) < bottom)
				if (((String) lines.get(max_child + 1))
						.compareTo((String) lines.get(max_child)) > 0)
					max_child++;

			if (((String) lines.get(root)).compareTo((String) lines
					.get(max_child)) < 0) {
				Object tmp = lines.get(root);
				lines.set(root, lines.get(max_child));
				lines.set(max_child, (String) tmp);
				root = max_child;
				max_child = root * 2 + 1;
			} else
				break;
		}
	}

}