servletutil.java

Jodd是一个开源的公用Java基础类库

package jodd.servlet;

import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import jodd.util.Base64;

/**
 * Miscellaneous servlet utils.
 */
public final class ServletUtil {

	/**
	 * Examines if request is a multipart.
	 *
	 * @param request http request
	 *
	 * @return <code>true</code> if request is multipart, otherwise <code>false</code>
	 */
	public static boolean isRequestMultipart(HttpServletRequest request) {
		String type = request.getHeader("Content-Type");
		if ((type == null) || !type.startsWith("multipart/form-data")) {
			return false;
		}
		return true;
	}


	// ---------------------------------------------------------------- authorization
	/**
	 * Decodes the "Authorization" header and retrieves the
	 * user's name from it.  Returns null if the header is not present.
	 *
	 * @param request
	 *
	 * @return user name
	 */
	public static String getAuthUsername(HttpServletRequest request) {
		String header = request.getHeader("Authorization");
		if (header == null) {
			return null;
		}
		String encoded = header.substring(header.indexOf(" ") + 1);
		String decoded = new String(Base64.decode(encoded));
		return decoded.substring(0, decoded.indexOf(":"));
	}

	/**
	 * Decodes the "Authorization" header and retrieves the
	 * password from it.  Returns null if the header is not present.
	 *
	 * @param request http request
	 *
	 * @return password
	 */
	public static String getAuthPassword(HttpServletRequest request) {
		String header = request.getHeader("Authorization");
		if (header == null) {
			return null;
		}
		String encoded = header.substring(header.indexOf(" ") + 1);
		String decoded = new String(Base64.decode(encoded));
		return decoded.substring(decoded.indexOf(":") +1);
	}

	/**
	 * Sends correct headers to require basic authentication for the
	 * given realm.
	 *
	 * @param resp	
	 * @param realm
	 *
	 * @exception IOException
	 */
	public static void requireAuthentication(HttpServletResponse resp, String realm) throws IOException {
		resp.setHeader("WWW-Authenticate", "Basic realm=\"" + realm + "\"");
		resp.sendError(HttpServletResponse.SC_UNAUTHORIZED);
	}


	// ---------------------------------------------------------------- cookie

	/**
	 * Returns cookie value from client.
	 *
	 * @param request    request
	 * @param cookieName name of the cookie
	 *
	 * @return cookie value or null if cookie with specified name doesn't exist.
	 */
	public static Cookie getCookie(HttpServletRequest request, String cookieName) {
		Cookie[] cookies = request.getCookies();
		if (cookies != null) {
			Cookie cookie;
			for (int i = 0; i < cookies.length; i++) {
				cookie = cookies[i];
				if (cookie.getName().equals(cookieName)) {
					return cookie;
				}
			}
		}
		return null;
	}

	// ---------------------------------------------------------------- GET parameters

	/**
	 * Iterates the map and creates parameters suffix string. First character is
	 * not created, so this method may be used in both ways:
	 * <ol>for creating the complete url params</ol>
	 * <ol>for creating just one part of the url params</ol>
	 *
	 * All values (but not params) are url encoded.
	 *
	 * @param map
	 *
	 * @return url parameters
	 */
	public static String makeUrlParams(Map map) {
		StringBuffer sb = new StringBuffer();
		Iterator i = map.keySet().iterator();
		boolean first = true;
		while (i.hasNext()) {
			if (first == false) {
				sb.append('&');
			} else {
				first = false;
			}
			String key = (String) i.next();
			sb.append(key).append('=');
			sb.append(HtmlEncoder.encodeUrl((String) map.get(key)));
		}
		return sb.toString();
	}


	/**
	 * Creates Map from the given URL String with all parameter/value pairs
	 * extracted from it. Valid URL is expected (i.e. uri?p1=v1&p2=...). Values
	 * are decoded into regular strings.
	 *
	 * @param url    url
	 *
	 * @return map with param/value pairs extracted from url
	 */
	public static HashMap getUrlParams(String url) {
		HashMap map = new HashMap();
		if (url == null) {
			return map;
		}
		int urlLength = url.length();

		// skip uri part
		int j = 0;
		int i = url.indexOf('?');
		if (i != -1) {
			j = i + 1;
		} else {
			return map;
		}
		if (j >= urlLength) {
			return map;
		}

		
		// find params
		while (j < urlLength) {
			i = url.indexOf('&', j);
			if (i == -1) {
				i = urlLength;
			}
			int e = url.indexOf('=', j);
			if (e == -1) {
				e = urlLength;
			}
			if (e < i) {
				map.put(url.substring(j, e), HtmlEncoder.decodeUrl(url.substring(e + 1, i)));
			} else {
				if (j != i) {
					map.put(url.substring(j, i), "");
				}
			}
			j = i + 1;
		}
		return map;
	}


}