java获取网页的编码

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;

public class WebEncoding {

	public static String getEncoding(HttpURLConnection httpUrlConnection)
			throws IOException {
		String contentEncoding = httpUrlConnection.getContentEncoding();
		String contentType = httpUrlConnection.getContentType();
		InputStream inputStream = httpUrlConnection.getInputStream();
		if (contentEncoding == null) {

			int index = contentType.indexOf("=");
			if (index == -1) {
				System.out.println("----contentType----");
				return getEncodingByInputStream(inputStream);
			} else {
				System.out.println("----InputStream----");
				String t = contentType.substring(index + 1);
				return t.toUpperCase();
			}
		} else {
			System.out.println("----contentEncoding----");
			return contentEncoding;
		}
	}

	public static String getEncodingByInputStream(InputStream inputStream) {
		try {
			StringBuffer sb = new StringBuffer("1234567");
			StringBuffer sb2 = new StringBuffer();
			int t;
			while ((t = inputStream.read()) != -1) {
				sb.deleteCharAt(0);
				sb.append((char) t);
				if (sb.toString().toLowerCase().equals("charset")) {
					for (int i = 0; i < 10; i++) {
						char c = (char) inputStream.read();
						sb2.append(c);
					}
					break;
				}

			}
			String str = sb2.toString();
			int si = str.indexOf("=") + 1;
			int ei = str.indexOf("\"");
			String encoding = str.substring(si, ei).trim().toUpperCase();
			return encoding;
		} catch (IOException e) {
			e.printStackTrace();
			return "UTF-8";
		}
	}
}