TextHelper.java

package com.ch_linghu.fanfoudroid.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import android.text.Html;
import android.text.util.Linkify;
import android.util.Log;
import android.widget.TextView;
import android.widget.TextView.BufferType;

public class TextHelper {
	private static final String TAG = "TextHelper";

	public static String stringifyStream(InputStream is) throws IOException {
		BufferedReader reader = new BufferedReader(new InputStreamReader(is));
		StringBuilder sb = new StringBuilder();
		String line;

		while ((line = reader.readLine()) != null) {
			sb.append(line + "\n");
		}

		return sb.toString();
	}

	private static HashMap<String, String> _userLinkMapping = new HashMap<String, String>();

	private static final Pattern NAME_MATCHER = Pattern.compile("@.+?\\s");
	private static final Linkify.MatchFilter NAME_MATCHER_MATCH_FILTER = new Linkify.MatchFilter() {
		@Override
		public final boolean acceptMatch(final CharSequence s, final int start,
				final int end) {

			String name = s.subSequence(start + 1, end).toString().trim();
			boolean result = _userLinkMapping.containsKey(name);
			return result;
		}
	};

	private static final Linkify.TransformFilter NAME_MATCHER_TRANSFORM_FILTER = new Linkify.TransformFilter() {

		@Override
		public String transformUrl(Matcher match, String url) {
			// TODO Auto-generated method stub
			String name = url.subSequence(1, url.length()).toString().trim();
			return _userLinkMapping.get(name);
		}
	};

	private static final String TWITTA_USER_URL = "twitta://users/";

	public static void linkifyUsers(TextView view) {
		Linkify.addLinks(view, NAME_MATCHER, TWITTA_USER_URL,
				NAME_MATCHER_MATCH_FILTER, NAME_MATCHER_TRANSFORM_FILTER);
	}

	private static final Pattern TAG_MATCHER = Pattern.compile("#\\w+#");

	private static final Linkify.TransformFilter TAG_MATCHER_TRANSFORM_FILTER = new Linkify.TransformFilter() {
		@Override
		public final String transformUrl(Matcher match, String url) {
			String result = url.substring(1, url.length() - 1);
			return result;
		}
	};

	private static final String TWITTA_SEARCH_URL = "twitta://search/";

	public static void linkifyTags(TextView view) {
		Linkify.addLinks(view, TAG_MATCHER, TWITTA_SEARCH_URL, null,
				TAG_MATCHER_TRANSFORM_FILTER);
	}

	private static Pattern USER_LINK = Pattern
			.compile("@<a href=\"http:\\/\\/fanfou\\.com\\/(.*?)\" class=\"former\">(.*?)<\\/a>");

	private static String preprocessText(String text) {
		// 处理HTML格式返回的用户链接
		Matcher m = USER_LINK.matcher(text);
		while (m.find()) {
			_userLinkMapping.put(m.group(2), m.group(1));
			Log.d(TAG,
					String.format("Found mapping! %s=%s", m.group(2),
							m.group(1)));
		}

		// 将User Link的连接去掉
		StringBuffer sb = new StringBuffer();
		m = USER_LINK.matcher(text);
		while (m.find()) {
			m.appendReplacement(sb, "@$2");
		}
		m.appendTail(sb);
		return sb.toString();
	}

	public static String getSimpleTweetText(String text) {
		return Html.fromHtml(text).toString();
	}

	public static void setSimpleTweetText(TextView textView, String text) {
		String processedText = getSimpleTweetText(text);
		textView.setText(processedText);
	}

	public static void setTweetText(TextView textView, String text) {
		String processedText = preprocessText(text);
		textView.setText(Html.fromHtml(processedText), BufferType.SPANNABLE);
		Linkify.addLinks(textView, Linkify.WEB_URLS | Linkify.EMAIL_ADDRESSES);
		linkifyUsers(textView);
		linkifyTags(textView);
		_userLinkMapping.clear();
	}
	


	/**
	 * 从消息中获取全部提到的人，将它们按先后顺序放入一个列表
	 * 
	 * @param msg
	 *            消息文本
	 * @return 消息中@的人的列表，按顺序存放
	 */
	public static List<String> getMentions(String msg) {
		ArrayList<String> mentionList = new ArrayList<String>();

		final Pattern p = Pattern.compile("@(.*?)\\s");
		final int MAX_NAME_LENGTH = 12; // 简化判断，无论中英文最长12个字

		Matcher m = p.matcher(msg);
		while (m.find()) {
			String mention = m.group(1);

			// 过长的名字就忽略（不是合法名字） +1是为了补上“@”所占的长度
			if (mention.length() <= MAX_NAME_LENGTH + 1) {
				// 避免重复名字
				if (!mentionList.contains(mention)) {
					mentionList.add(m.group(1));
				}
			}
		}
		return mentionList;
	}
}