private String getDefault(char[] words1, char[] words2) {
		char word1 = ' ';
		char word2 = ' ';
		System.out.println("choose default");
		int maxCount = 0;
		char maxChar = ' ';
		boolean hasChanegd2 = false;
		for(int i = 0; i < words1.length; i++) {
			int index = words_.indexOf(words1[i]);
			if(index == -1)
				continue;
			int count = wordCount_.get(index);
			if(count > maxCount) {
				hasChanegd2 = true;
				maxCount = count;
				maxChar = words1[i];
			}
		}
		if(!hasChanegd2) {
			/**
			 * 即在选择默认字时，该读音内候选字都没有在语料库中出现。这是语料库太小所致。
			 */
			System.out.println("error in InputMethod:getDefault1:hasChanegd2");
			maxChar = words1[0];
		}
		word1 = maxChar;
		maxCount = 0;
		maxChar = ' ';
		hasChanegd2 = false;
		for(int i = 0; i < words2.length; i++) {
			int index = words_.indexOf(words2[i]);
			if(index == -1)
				continue;
			int count = wordCount_.get(index);
			if(count > maxCount) {
				hasChanegd2 = true;
				maxCount = count;
				maxChar = words2[i];
			}
		}
		if(!hasChanegd2) {
			/**
			 * 即在选择默认字时，该读音内候选字都没有在语料库中出现。这是语料库太小所致。
			 */
			System.out.println("error in InputMethod:getDefault2:hasChanegd2");
			maxChar = words2[0];
		}
		word2 = maxChar;
		StringBuffer sb = new StringBuffer();
		sb.append(word1);
		sb.append(word2);
		return sb.toString();
	}