tapestry/tapestry-framework/src/java/org/apache/tapestry/multipart/IMultipartDecoder.java

// Copyright 2004, 2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package org.apache.tapestry.multipart;

import javax.servlet.http.HttpServletRequest;

import org.apache.tapestry.request.IUploadFile;

/**
 * Defines how a multipart HTTP request can be broken into individual elements
 * (including file uploads).
 * <p>
 * Multipart decoder implementations must be threadsafe.
 * 
 * @author Howard Lewis Ship
 * @since 2.3
 */

public interface IMultipartDecoder
{

    /**
     * Decodes the incoming request, identifying all the parts (values and
     * uploaded files) contained within.
     */

    void decode(HttpServletRequest request);

    /**
     * Invoked to release any resources needed by tghe decoder. In some cases,
     * large incoming parts are written to temporary files; this method ensures
     * those temporary files are deleted.
     */

    void cleanup(HttpServletRequest request);

    /**
     * Returns the single value (or first value) for the parameter with the
     * specified name. Returns null if no such parameter was in the request.
     */

    String getString(HttpServletRequest request, String name);

    /**
     * Returns an array of values (possibly a single element array). Returns
     * null if no such parameter was in the request.
     */

    String[] getStrings(HttpServletRequest request, String name);

    /**
     * Returns the uploaded file with the specified parameter name, or null if
     * no such parameter was in the request.
     */

    IUploadFile getUploadFile(HttpServletRequest request, String name);

    /**
     * Returns the names of all parameters whose type is string (not file
     * upload).
     * 
     * @since 4.0
     */
    String[] getStringParameterNames(HttpServletRequest request);
}