browseservlet.java

dspace 用j2ee架构的一个数字图书馆.开源程序

                 */
                if (!oldestFirst)
                {
                    startsWith = startsWith + "-32";
                }
            }

            scope.setFocus(startsWith);
            highlight = true;
            logInfo = "starts_with=" + startsWith + ",";
        }
        else if ((top != null) || (bottom != null))
        {
            // ----------------------------------------------
            // Paginating: put specified entry at top or bottom
            // ----------------------------------------------
            // Use a single value and a boolean to simplify the code below
            String val = bottom;
            boolean isTop = false;

            if (top != null)
            {
                val = top;
                isTop = true;
            }

            if (browseAuthors || browseSubjects)
            {
                // Value will be a text value for author browse
                scope.setFocus(val);
            }
            else
            {
                // Value is Handle if we're browsing items by title or date
                Item item = (Item) HandleManager.resolveToObject(context, val);

                if (item == null)
                {
                    // Handle is invalid one. Show an error.
                    JSPManager.showInvalidIDError(request, response, focus,
                            Constants.ITEM);

                    return;
                }

                scope.setFocus(item);
            }

            // This entry appears at the top or bottom, and so needs to have
            // 0 or 20 entries shown before it
            scope.setNumberBefore(isTop ? 0 : 20);

            logInfo = (isTop ? "top" : "bottom") + "=" + val + ",";

            if (browseDates)
            {
                // If the date order is flipped, we'll flip the table upside
                // down - i.e. the top will become the bottom and the bottom
                // the top.
                if (top != null)
                {
                    flipOrderingQuery = "bottom="
                            + URLEncoder
                                    .encode(top, Constants.DEFAULT_ENCODING)
                            + "&";
                }
                else
                {
                    flipOrderingQuery = "top="
                            + URLEncoder.encode(bottom,
                                    Constants.DEFAULT_ENCODING) + "&";
                }
            }
        }

        // ----------------------------------------------
        // If none of the above apply, no positioning parameters
        // set - use start of index
        // ----------------------------------------------
        // Are we in a community or collection?
        Community community = UIUtil.getCommunityLocation(request);
        Collection collection = UIUtil.getCollectionLocation(request);

        if (collection != null)
        {
            logInfo = logInfo + ",collection_id=" + collection.getID() + ",";
            scope.setScope(collection);
        }
        else if (community != null)
        {
            logInfo = logInfo + ",community_id=" + community.getID() + ",";
            scope.setScope(community);
        }

        BrowseInfo browseInfo;

        // Query the browse index
        if (browseAuthors)
        {
            browseInfo = Browse.getAuthors(scope);
        }
        else if (browseDates)
        {
            browseInfo = Browse.getItemsByDate(scope, oldestFirst);
        }
        else if (browseSubjects)
        {
            browseInfo = Browse.getSubjects(scope);
        }
        else
        {
            browseInfo = Browse.getItemsByTitle(scope);
        }

        // Write log entry
        String what = "title";

        if (browseAuthors)
        {
            what = "author";
        }
        else if (browseSubjects)
        {
            what = "subject";
        }
        else if (browseDates)
        {
            what = "date";
        }

        log.info(LogManager.getHeader(context, "browse_" + what, logInfo
                + "results=" + browseInfo.getResultCount()));

        if (browseInfo.getResultCount() == 0)
        {
            // No results!
            request.setAttribute("community", community);
            request.setAttribute("collection", collection);

            JSPManager.showJSP(request, response, "/browse/no-results.jsp");
        }
        else
        {
            // Work out what the query strings will be for the previous
            // and next pages
            if (!browseInfo.isFirst())
            {
                // Not the first page, so we'll need a "previous page" button
                // The top entry of the current page becomes the bottom
                // entry of the "previous page"
                String s;

                if (browseAuthors || browseSubjects) //aneesh
                {
                    s = (browseInfo.getStringResults())[0];
                }
                else
                {
                    Item firstItem = (browseInfo.getItemResults())[0];
                    s = firstItem.getHandle();
                }

                if (browseDates && oldestFirst)
                {
                    // For browsing by date, oldest first, we need
                    // to add the ordering parameter
                    request.setAttribute("previous.query",
                            "order=oldestfirst&bottom="
                                    + URLEncoder.encode(s,
                                            Constants.DEFAULT_ENCODING));
                }
                else
                {
                    request.setAttribute("previous.query", "bottom="
                            + URLEncoder.encode(s, Constants.DEFAULT_ENCODING));
                }
            }

            if (!browseInfo.isLast())
            {
                // Not the last page, so we'll need a "next page" button
                // The bottom entry of the current page will be the top
                // entry in the next page
                String s;

                if (browseAuthors)
                {
                    String[] authors = browseInfo.getStringResults();
                    s = authors[authors.length - 1];
                }
                else if (browseSubjects)
                {
                    String[] subjects = browseInfo.getStringResults();
                    s = subjects[subjects.length - 1];
                }
                else
                {
                    Item[] items = browseInfo.getItemResults();
                    Item lastItem = items[items.length - 1];
                    s = lastItem.getHandle();
                }

                if (browseDates && oldestFirst)
                {
                    // For browsing by date, oldest first, we need
                    // to add the ordering parameter
                    request.setAttribute("next.query", "order=oldestfirst&top="
                            + URLEncoder.encode(s, Constants.DEFAULT_ENCODING));
                }
                else
                {
                    request.setAttribute("next.query", "top="
                            + URLEncoder.encode(s, Constants.DEFAULT_ENCODING));
                }
            }

            // Set appropriate attributes and forward to results page
            request.setAttribute("community", community);
            request.setAttribute("collection", collection);
            request.setAttribute("browse.info", browseInfo);
            request.setAttribute("highlight", new Boolean(highlight));

            if (browseAuthors)
            {
                JSPManager.showJSP(request, response, "/browse/authors.jsp");
            }
            else if (browseSubjects)
            {
                JSPManager.showJSP(request, response, "/browse/subjects.jsp");
            }
            else if (browseDates)
            {
                request.setAttribute("oldest.first", new Boolean(oldestFirst));
                request.setAttribute("flip.ordering.query", flipOrderingQuery);
                JSPManager.showJSP(request, response,
                        "/browse/items-by-date.jsp");
            }
            else
            {
                JSPManager.showJSP(request, response,
                        "/browse/items-by-title.jsp");
            }
        }
    }
}