Package jodd.servlet

Source Code of jodd.servlet.ServletUtil

// Copyright (c) 2003-2014, Jodd Team (jodd.org). All Rights Reserved.

package jodd.servlet;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.File;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.Enumeration;

import javax.servlet.ServletRequest;
import javax.servlet.ServletContext;
import javax.servlet.jsp.PageContext;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import jodd.io.StreamUtil;
import jodd.util.Base64;
import jodd.util.StringPool;
import jodd.util.MimeTypes;
import jodd.io.FileNameUtil;
import jodd.servlet.upload.MultipartRequestWrapper;
import jodd.servlet.upload.MultipartRequest;
import jodd.upload.FileUpload;
import jodd.util.StringUtil;
import jodd.util.URLCoder;

/**
* Miscellaneous servlet utilities.
*/
public class ServletUtil {

  public static final String HEADER_CONTENT_TYPE = "Content-Type";
  public static final String TYPE_MULTIPART_FORM_DATA = "multipart/form-data";
  public static final String HEADER_AUTHORIZATION = "Authorization";
  public static final String HEADER_ACCEPT_ENCODING = "Accept-Encoding";
  public static final String CONTENT_DISPOSITION = "Content-Disposition";
  public static final String WWW_AUTHENTICATE = "WWW-Authenticate";
  private static final String JAVAX_SERVLET_ERROR_EXCEPTION = "javax.servlet.error.exception";

  private static final String SCOPE_APPLICATION = "application";
  private static final String SCOPE_SESSION = "session";
  private static final String SCOPE_REQUEST = "request";
  private static final String SCOPE_PAGE = "page";


  // ---------------------------------------------------------------- multi-part

  /**
   * Returns <code>true</code> if a request is multi-part request.
   */
  public static boolean isMultipartRequest(HttpServletRequest request) {
    String type = request.getHeader(HEADER_CONTENT_TYPE);
    return (type != null) && type.startsWith(TYPE_MULTIPART_FORM_DATA);
  }

  /**
   * Returns <code>true</code> if client supports gzip encoding.
   */
  public static boolean isGzipSupported(HttpServletRequest request) {
    String browserEncodings = request.getHeader(HEADER_ACCEPT_ENCODING);
    return (browserEncodings != null) && (browserEncodings.contains("gzip"));
  }

  // ---------------------------------------------------------------- authorization
  /**
   * Decodes the "Authorization" header and retrieves the
   * user's name from it.  Returns <code>null</code> if the header is not present.
   */
  public static String getAuthUsername(HttpServletRequest request) {
    String header = request.getHeader(HEADER_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 <code>null</code> if the header is not present.
   */
  public static String getAuthPassword(HttpServletRequest request) {
    String header = request.getHeader(HEADER_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.
   */
  public static void requireAuthentication(HttpServletResponse resp, String realm) throws IOException {
    resp.setHeader(WWW_AUTHENTICATE, "Basic realm=\"" + realm + '\"');
    resp.sendError(HttpServletResponse.SC_UNAUTHORIZED);
  }

  // ---------------------------------------------------------------- download and content disposition

  /**
   * Prepares response for file download. Mime type and size is resolved from the file.
   */
  public static void prepareDownload(HttpServletResponse response, File file) {
    prepareDownload(response, file, null);
  }

  /**
   * Prepares response for file download with provided mime type.
   */
  public static void prepareDownload(HttpServletResponse response, File file, String mimeType) {
    if (file.exists() == false) {
      throw new IllegalArgumentException("File not found: " + file);
    }
    if (file.length() > Integer.MAX_VALUE) {
      throw new IllegalArgumentException("File too big: " + file);
    }
    prepareResponse(response, file.getAbsolutePath(), mimeType, (int) file.length());
  }

  /**
   * Prepares response for various provided data.
   *
   * @param response http response
   * @param fileName file name, if full path then file name will be stripped, if null, will be ignored.
   * @param mimeType mime type with optional charset, may be <code>null</code>
   * @param fileSize if less then 0 it will be ignored
   */
  public static void prepareResponse(HttpServletResponse response, String fileName, String mimeType, int fileSize) {
    if ((mimeType == null) && (fileName != null)) {
      String extension = FileNameUtil.getExtension(fileName);
      mimeType = MimeTypes.getMimeType(extension);
    }

    if (mimeType != null) {
      response.setContentType(mimeType);
    }

    if (fileSize >= 0) {
      response.setContentLength(fileSize);
    }

    if (fileName != null) {
      String name = FileNameUtil.getName(fileName);
      response.setHeader(CONTENT_DISPOSITION, "attachment;filename=\"" + name + '\"');
    }
  }

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

  /**
   * Finds and returns cookie from client by its name.
   * Only the first cookie is returned.
   * @see #getAllCookies(javax.servlet.http.HttpServletRequest, String)
   * @return cookie value or <code>null</code> if cookie with specified name doesn't exist.
   */
  public static Cookie getCookie(HttpServletRequest request, String cookieName) {
    Cookie[] cookies = request.getCookies();
    if (cookies != null) {
      for (Cookie cookie : cookies) {
        if (cookie.getName().equals(cookieName)) {
          return cookie;
        }
      }
    }
    return null;
  }

  /**
   * Returns all cookies from client that matches provided name.
   * @see #getCookie(javax.servlet.http.HttpServletRequest, String)
   */
  public static Cookie[] getAllCookies(HttpServletRequest request, String cookieName) {
    Cookie[] cookies = request.getCookies();
    if (cookies == null) {
      return null;
    }
    ArrayList<Cookie> list = new ArrayList<Cookie>(cookies.length);
    for (Cookie cookie : cookies) {
      if (cookie.getName().equals(cookieName)) {
        list.add(cookie);
      }
    }
    if (list.isEmpty()) {
      return null;
    }
    return list.toArray(new Cookie[list.size()]);
  }

  // ---------------------------------------------------------------- request body

  /**
   * Reads HTTP request body. Useful only with POST requests. Once body is read,
   * it cannot be read again!
   */
  public static String readRequestBody(HttpServletRequest request) throws IOException {
    BufferedReader buff = request.getReader();
    StringWriter out = new StringWriter();
    StreamUtil.copy(buff, out);
    return out.toString();
  }


  // ---------------------------------------------------------------- context path

  /**
   * Returns correct context path, as by Servlet definition. Different
   * application servers return all variants: "", null, "/".
   * <p>
   * The context path always comes first in a request URI. The path
   * starts with a "/" character but does not end with a "/" character.
   * For servlets in the default (root) context, this method returns "".
   */
  public static String getContextPath(HttpServletRequest request) {
    String contextPath = request.getContextPath();
    if (contextPath == null || contextPath.equals(StringPool.SLASH)) {
      contextPath = StringPool.EMPTY;
    }
    return contextPath;
  }

  /**
   * Returns correct context path, as by Servlet definition. Different
   * application servers return all variants: "", null, "/".
   * <p>
   * The context path always comes first in a request URI. The path
   * starts with a "/" character but does not end with a "/" character.
   * For servlets in the default (root) context, this method returns "".
   */
  public static String getContextPath(ServletContext servletContext) {
    String contextPath = servletContext.getContextPath();
    if (contextPath == null || contextPath.equals(StringPool.SLASH)) {
      contextPath = StringPool.EMPTY;
    }
    return contextPath;
  }

  /**
   * @see #getContextPath(javax.servlet.ServletContext)
   */
  public static String getContextPath(PageContext pageContext) {
    return getContextPath(pageContext.getServletContext());
  }

  /**
   * Stores context path in server context and request scope.
   */
  public static void storeContextPath(PageContext pageContext, String contextPathVariableName) {
    String ctxPath = getContextPath(pageContext);

    HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
    request.setAttribute(contextPathVariableName, ctxPath);

    ServletContext servletContext = pageContext.getServletContext();
    servletContext.setAttribute(contextPathVariableName, ctxPath);
  }

  /**
   * Stores context path in page context and request scope.
   */
  public static void storeContextPath(ServletContext servletContext, String contextPathVariableName) {
    String ctxPath = getContextPath(servletContext);

    servletContext.setAttribute(contextPathVariableName, ctxPath);
  }

  // ---------------------------------------------------------------- attributes and values

  /**
   * Returns non-<code>null</code> attribute value. Scopes are examined in the
   * following order: page, request, session, application.
   */
  public static Object attribute(PageContext pageContext, String name) {
    Object value = pageContext.getAttribute(name);
    if (value != null) {
      return value;
    }
    return attribute((HttpServletRequest) pageContext.getRequest(), name);
  }
  /**
   * Returns non-<code>null</code> attribute value. Scopes are examined in the
   * following order: request, session, application.
   */
  public static Object attribute(HttpServletRequest request, String name) {
    Object value = request.getAttribute(name);
    if (value != null) {
      return value;
    }
    value = request.getSession().getAttribute(name);
    if (value != null) {
      return value;
    }
    return request.getSession().getServletContext().getAttribute(name);
  }

  /**
   * Returns value of property/attribute. The following value sets are looked up:
   * <ul>
   *     <li>page context attributes</li>
   *     <li>request attributes</li>
   *     <li>request parameters (multi-part request detected)</li>
   *     <li>session attributes</li>
   *     <li>context attributes</li>
   * </ul>
   */
  public static Object value(PageContext pageContext, String name) {
    Object value = pageContext.getAttribute(name);
    if (value != null) {
      return value;
    }
    return value((HttpServletRequest) pageContext.getRequest(), name);
  }

  /**
   * Returns value of property/attribute. The following value sets are looked up:
   * <ul>
   *     <li>request attributes</li>
   *     <li>request parameters (multi-part request detected)</li>
   *     <li>session attributes</li>
   *     <li>context attributes</li>
   * </ul>
   */
  public static Object value(HttpServletRequest request, String name) {
    Object value = request.getAttribute(name);
    if (value != null) {
      return value;
    }

    if (isMultipartRequest(request)) {
      try {
        MultipartRequest multipartRequest = MultipartRequest.getInstance(request);
        value = multipartRequest.getParameter(name);
      } catch (IOException ignore) {
      }
    }
    else {
      value = request.getParameter(name);
    }
    if (value != null) {
      return value;
    }

    value = request.getSession().getAttribute(name);
    if (value != null) {
      return value;
    }
    return request.getSession().getServletContext().getAttribute(name);
  }

  // ---------------------------------------------------------------- scope attributes

  /**
   * Sets scope attribute.
   */
  public static void setScopeAttribute(String name, Object value, String scope, PageContext pageContext) {
    HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
    String scopeValue = scope != null ? scope.toLowerCase() : SCOPE_PAGE;
    if (scopeValue.equals(SCOPE_PAGE)) {
      pageContext.setAttribute(name, value);
    }
    else if (scopeValue.equals(SCOPE_REQUEST)) {
      request.setAttribute(name, value);
    }
    else if (scopeValue.equals(SCOPE_SESSION)) {
      request.getSession().setAttribute(name, value);
    }
    else if (scopeValue.equals(SCOPE_APPLICATION)) {
            request.getSession().getServletContext().setAttribute(name, value);
        }
    else {
      throw new IllegalArgumentException("Invalid scope: " + scope);
        }
  }

  /**
   * Removes scope attribute.
   */
  public static void removeScopeAttribute(String name, String scope, PageContext pageContext) {
    HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
    String scopeValue = scope != null ? scope.toLowerCase() : SCOPE_PAGE;
    if (scopeValue.equals(SCOPE_PAGE)) {
      pageContext.removeAttribute(name);
    }
    else if (scopeValue.equals(SCOPE_REQUEST)) {
      request.removeAttribute(name);
    }
    else if (scopeValue.equals(SCOPE_SESSION)) {
      request.getSession().removeAttribute(name);
    }
    else if (scopeValue.equals(SCOPE_APPLICATION)) {
            request.getSession().getServletContext().removeAttribute(name);
        }
    else {
      throw new IllegalArgumentException("Invalid scope: " + scope);
        }
  }

  // ---------------------------------------------------------------- resolve URL

  /**
   * Valid characters in a scheme, as specified by RFC 1738.
   */
  public static final String VALID_SCHEME_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+.-";

  /**
     * Returns <code>true</code> if current URL is absolute, <code>false</code> otherwise.
     */
    public static boolean isAbsoluteUrl(String url) {
      if (url == null) {            // a null URL is not absolute
        return false;
      }
      int colonPos;                   // fast simple check first
      if ((colonPos = url.indexOf(':')) == -1) {
        return false;
      }

      // if we DO have a colon, make sure that every character
      // leading up to it is a valid scheme character
      for (int i = 0; i < colonPos; i++) {
        if (VALID_SCHEME_CHARS.indexOf(url.charAt(i)) == -1) {
          return false;
        }
      }
      return true;
    }

  /**
   * Strips a servlet session ID from <code>url</code>.  The session ID
   * is encoded as a URL "path parameter" beginning with "jsessionid=".
   * We thus remove anything we find between ";jsessionid=" (inclusive)
   * and either EOS or a subsequent ';' (exclusive).
   */
  public static String stripSessionId(String url) {
    StringBuilder u = new StringBuilder(url);
    int sessionStart;
    while ((sessionStart = u.toString().indexOf(";jsessionid=")) != -1) {
      int sessionEnd = u.toString().indexOf(';', sessionStart + 1);
      if (sessionEnd == -1) {
        sessionEnd = u.toString().indexOf('?', sessionStart + 1);
      }
      if (sessionEnd == -1) {
        sessionEnd = u.length();
      }
      u.delete(sessionStart, sessionEnd);
    }
    return u.toString();
  }

  public static String resolveUrl(String url, HttpServletRequest request) {
    if (isAbsoluteUrl(url)) {
      return url;
    }
    if (url.startsWith(StringPool.SLASH)) {
      return getContextPath(request) + url;
    } else {
      return url;
    }
  }

  public static String resolveUrl(String url, String context) {
    if (isAbsoluteUrl(url)) {
      return url;
    }
    if (!context.startsWith(StringPool.SLASH) || !url.startsWith(StringPool.SLASH)) {
      throw new IllegalArgumentException("Values of both 'context' and 'url' must start with '/'.");
    }
    if (context.equals(StringPool.SLASH)) {
      return url;
    } else {
      return (context + url);
    }
  }

  // ---------------------------------------------------------------- params

  /**
   * Returns HTTP request parameter as String or String[].
   */
  public static Object getRequestParameter(ServletRequest request, String name) {
    String[] values = request.getParameterValues(name);
    if (values == null) {
      return null;
    }
    if (values.length == 1) {
      return values[0];
    }
    return values;
  }

  /**
   * Checks if some parameter is in GET parameters.
   */
  public boolean isGetParameter(HttpServletRequest request, String name) {
    name = URLCoder.encodeQueryParam(name) + '=';
    String query = request.getQueryString();
    String[] nameValuePairs = StringUtil.splitc(query, '&');
    for (String nameValuePair : nameValuePairs) {
      if (nameValuePair.startsWith(name)) {
        return true;
      }
    }
    return false;
  }

  /**
   * Prepares parameters for further processing.
   * @param paramValues  string array of param values
   * @param trimParams  trim parameters
   * @param treatEmptyParamsAsNull  empty parameters should be treated as <code>null</code>
   * @param ignoreEmptyRequestParams  if all parameters are empty, return <code>null</code>
   */
  public static String[] prepareParameters(
      String[] paramValues,
      boolean trimParams,
      boolean treatEmptyParamsAsNull,
      boolean ignoreEmptyRequestParams) {

    if (trimParams || treatEmptyParamsAsNull || ignoreEmptyRequestParams) {
      int emptyCount = 0;
      int total = paramValues.length;
      for (int i = 0; i < paramValues.length; i++) {
        String paramValue = paramValues[i];
        if (paramValue == null) {
          emptyCount++;
          continue;
        }
        if (trimParams) {
          paramValue = paramValue.trim();
        }
        if (paramValue.length() == 0) {
          emptyCount++;
          if (treatEmptyParamsAsNull) {
            paramValue = null;
          }
        }
        paramValues[i] = paramValue;
      }
      if ((ignoreEmptyRequestParams == true) && (emptyCount == total)) {
        return null;
      }
    }
    return paramValues;
  }


  // ---------------------------------------------------------------- copy

  /**
   * Copies all request parameters to attributes.
   */
  public static void copyParamsToAttributes(
      HttpServletRequest servletRequest,
      boolean trimParams,
      boolean treatEmptyParamsAsNull,
      boolean ignoreEmptyRequestParams) {

    Enumeration paramNames = servletRequest.getParameterNames();
    while (paramNames.hasMoreElements()) {
      String paramName = (String) paramNames.nextElement();
      if (servletRequest.getAttribute(paramName) != null) {
        continue;
      }

      String[] paramValues = servletRequest.getParameterValues(paramName);
      paramValues = prepareParameters(paramValues, trimParams, treatEmptyParamsAsNull, ignoreEmptyRequestParams);
      if (paramValues == null) {
        continue;
      }
      servletRequest.setAttribute(paramName, paramValues.length == 1 ? paramValues[0] : paramValues);
    }

    // multipart
    if ((servletRequest instanceof MultipartRequestWrapper) == false) {
      return;
    }
    MultipartRequestWrapper multipartRequest = (MultipartRequestWrapper) servletRequest;
    if (multipartRequest.isMultipart() == false) {
      return;
    }
    paramNames = multipartRequest.getFileParameterNames();
    while (paramNames.hasMoreElements()) {
      String paramName = (String) paramNames.nextElement();
      if (servletRequest.getAttribute(paramName) != null) {
        continue;
      }
      FileUpload[] paramValues = multipartRequest.getFiles(paramName);
      servletRequest.setAttribute(paramName, paramValues.length == 1 ? paramValues[0] : paramValues);
    }
  }

  // ---------------------------------------------------------------- version

  private static boolean isVersion2_5;

  static {
    try {
      ServletContext.class.getMethod("getContextPath");
      isVersion2_5 = true;
    } catch (Exception ignore) {
    }
  }

  /**
   * Returns <code>true</code> if current servlets version is 2.5 or higher.
   */
  public static boolean isServletsVersion2_5() {
    return isVersion2_5;
  }

  // ---------------------------------------------------------------- errors

  /**
   * Returns servlet error.
   */
  public static Throwable getServletError(ServletRequest request) {
    return (Throwable) request.getAttribute(JAVAX_SERVLET_ERROR_EXCEPTION);
  }

  /**
   * Sets servlet error.
   */
  public static void setServletError(ServletRequest request, Throwable throwable) {
    request.setAttribute(JAVAX_SERVLET_ERROR_EXCEPTION, throwable);
  }


  // ---------------------------------------------------------------- debug

  /**
   * Returns a string with debug info from all servlet objects.
   * @see #debug(HttpServletRequest, PageContext)
   */
  public static String debug(HttpServletRequest request) {
    return debug(request,  null);
  }
  /**
   * Returns a string with debug info from all servlet objects.
   * @see #debug(HttpServletRequest, PageContext)
   */
  public static String debug(PageContext pageContext) {
    return debug((HttpServletRequest) pageContext.getRequest(),  pageContext);
  }

  /**
   * Returns a string with debug info from all servlet objects, including the page context.
   */
  protected static String debug(HttpServletRequest request, PageContext pageContext) {
    StringBuilder result = new StringBuilder();
    result.append("\nPARAMETERS\n----------\n");
    Enumeration enumeration = request.getParameterNames();
    while (enumeration.hasMoreElements()) {
      String name = (String) enumeration.nextElement();
      Object[] value = request.getParameterValues(name);
      result.append(name).append('=');
      if (value == null) {
        result.append("<null>");
      } else if (value.length == 1) {
        result.append(value[0]).append('\n');
      } else {
        result.append('[');
        for (int i = 0, valueLength = value.length; i < valueLength; i++) {
          if (i == 0) {
            result.append(',');
          }
          result.append(value[i]);
        }
        result.append("]\n");
      }
    }

    HttpSession session = request.getSession();
    ServletContext context = session.getServletContext();

    loop:
    for (int i = 0; i < 4; i++) {
      switch (i) {
        case 0: result.append("\nREQUEST\n-------\n");
            enumeration = request.getAttributeNames();
            break;
        case 1: result.append("\nSESSION\n-------\n");
            enumeration = session.getAttributeNames();
            break;
        case 2: result.append("\nAPPLICATION\n-----------\n");
            enumeration = context.getAttributeNames();
            break;
        case 3if (pageContext == null) {
              break loop;
            }
            result.append("\nPAGE\n----\n");
            enumeration = pageContext.getAttributeNamesInScope(PageContext.PAGE_SCOPE);
      }
      while (enumeration.hasMoreElements()) {
        String name = (String) enumeration.nextElement();
        Object value = null;
        switch (i) {
          case 0: value = request.getAttribute(name); break;
          case 1: value = session.getAttribute(name); break;
          case 2: value = context.getAttribute(name); break;
          case 3: value = pageContext.getAttribute(name); break;
        }
        result.append(name).append('=');
        if (value == null) {
          result.append("<null>\n");
        } else {
          String stringValue;
          try {
            stringValue = value.toString();
          } catch (Exception ignore) {
            stringValue = "<" + value.getClass() + ">\n";
          }
          result.append(stringValue).append('\n');
        }
      }
    }
    return result.toString();
  }

  // ---------------------------------------------------------------- cache

  /**
   * Prevents HTTP cache.
   */
  public static void preventCaching(HttpServletResponse response) {
    response.setHeader("Cache-Control", "max-age=0, must-revalidate, no-cache, no-store, private, post-check=0, pre-check=0")// HTTP 1.1
    response.setHeader("Pragma","no-cache");        // HTTP 1.0
    response.setDateHeader ("Expires", 0);          // prevents caching at the proxy server
  }


}
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