tabletag.java

一个比较不错的java分页标签,有源代码,开发者 可以学习学习

            throw new InvalidTagAttributeValueException(getClass(), "sort", value); //$NON-NLS-1$
        }
    }

    /**
     * setter for the "requestURI" attribute. Context path is automatically added to path starting with "/".
     * @param value base URI for creating links
     */
    public void setRequestURI(String value)
    {
        this.requestUri = value;
    }

    /**
     * Setter for the "requestURIcontext" attribute.
     * @param value base URI for creating links
     */
    public void setRequestURIcontext(boolean value)
    {
        this.dontAppendContext = !value;
    }

    /**
     * Used to directly set a list (or any object you can iterate on).
     * @param value Object
     * @deprecated use setName() to get the object from the page or request scope instead of setting it directly here
     */
    public void setList(Object value)
    {
        this.listAttribute = value;
    }

    /**
     * Sets the name of the object to use for iteration.
     * @param value name of the object to use for iteration (can contain expression). It also supports direct setting of
     * a list, for jsp 2.0 containers where users can set up a data source here using EL expressions.
     */
    public void setName(Object value)
    {
        if (value instanceof String)
        {
            // ok, assuming this is the name of the object
            this.name = (String) value;
        }
        else
        {
            // is this the list?
            this.list = value;
        }
    }

    /**
     * Sets the name of the object to use for iteration. This setter is needed for jsp 1.1 container which doesn't
     * support the String - Object conversion. The bean info class will swith to this setter.
     * @param value name of the object
     */
    public void setNameString(String value)
    {
        this.name = value;
    }

    /**
     * sets the sorting order for the sorted column.
     * @param value "ascending" or "descending"
     * @throws InvalidTagAttributeValueException if value is not one of "ascending" or "descending"
     */
    public void setDefaultorder(String value) throws InvalidTagAttributeValueException
    {
        this.defaultSortOrder = SortOrderEnum.fromName(value);
        if (this.defaultSortOrder == null)
        {
            throw new InvalidTagAttributeValueException(getClass(), "defaultorder", value); //$NON-NLS-1$
        }
    }

    /**
     * Setter for the decorator class name.
     * @param decorator fully qualified name of the table decorator to use
     */
    public void setDecorator(String decorator)
    {
        this.decoratorName = decorator;
    }

    /**
     * Is export enabled?
     * @param value <code>true</code> if export should be enabled
     */
    public void setExport(boolean value)
    {
        this.export = value;
    }

    /**
     * The variable name in which the totals map is stored.
     * @param varTotalsName the value
     */
    public void setVarTotals(String varTotalsName)
    {
        this.varTotals = varTotalsName;
    }

    /**
     * Get the name that the totals should be stored under.
     * @return the var name in pageContext
     */
    public String getVarTotals()
    {
        return this.varTotals;
    }

    /**
     * sets the number of items to be displayed in the page.
     * @param value number of items to display in a page
     */
    public void setLength(int value)
    {
        this.length = value;
    }

    /**
     * sets the index of the default sorted column.
     * @param value index of the column to sort
     */
    public void setDefaultsort(int value)
    {
        // subtract one (internal index is 0 based)
        this.defaultSortedColumn = value - 1;
    }

    /**
     * sets the number of items that should be displayed for a single page.
     * @param value number of items that should be displayed for a single page
     */
    public void setPagesize(int value)
    {
        this.pagesize = value;
    }

    /**
     * tells display tag that the values contained in the list are the viewable data only, there may be more results not
     * given to displaytag
     * @param partialList boolean value telling us there may be more data not given to displaytag
     */
    public void setPartialList(boolean partialList)
    {
        this.partialList = partialList;
    }

    /**
     * Setter for the list offset attribute.
     * @param value String
     */
    public void setOffset(int value)
    {
        if (value < 1)
        {
            // negative values has no meaning, simply treat them as 0
            this.offset = 0;
        }
        else
        {
            this.offset = value - 1;
        }
    }

    /**
     * Sets the unique id used to identify for this table.
     * @param value String
     */
    public void setUid(String value)
    {
        this.uid = value;
    }

    /**
     * Returns the unique id used to identify for this table.
     * @return id for this table
     */
    public String getUid()
    {
        return this.uid;
    }

    /**
     * Returns the properties.
     * @return TableProperties
     */
    protected TableProperties getProperties()
    {
        return this.properties;
    }

    /**
     * Returns the base href with parameters. This is the instance used for links, need to be cloned before being
     * modified.
     * @return base Href with parameters
     */
    protected Href getBaseHref()
    {
        return this.baseHref;
    }

    /**
     * Called by interior column tags to help this tag figure out how it is supposed to display the information in the
     * List it is supposed to display.
     * @param column an internal tag describing a column in this tableview
     */
    public void addColumn(HeaderCell column)
    {
        if (log.isDebugEnabled())
        {
            log.debug("[" + getUid() + "] addColumn " + column);
        }

        if ((this.paginatedList != null) && (column.getSortable()))
        {
            String sortCriterion = paginatedList.getSortCriterion();

            String sortProperty = column.getSortProperty();
            if (sortProperty == null)
            {
                sortProperty = column.getBeanPropertyName();
            }

            if ((sortCriterion != null) && sortCriterion.equals(sortProperty))
            {
                this.tableModel.setSortedColumnNumber(this.tableModel.getNumberOfColumns());
                column.setAlreadySorted();
            }
        }

        this.tableModel.addColumnHeader(column);
    }

    /**
     * Adds a cell to the current row. This method is usually called by a contained ColumnTag
     * @param cell Cell to add to the current row
     */
    public void addCell(Cell cell)
    {
        // check if null: could be null if list is empty, we don't need to fill rows
        if (this.currentRow != null)
        {
            int columnNumber = this.currentRow.getCellList().size();
            this.currentRow.addCell(cell);

            // just be sure that the number of columns has not been altered by conditionally including column tags in
            // different rows. This is not supported, but better avoid IndexOutOfBounds...
            if (columnNumber < tableModel.getHeaderCellList().size())
            {
                HeaderCell header = (HeaderCell) tableModel.getHeaderCellList().get(columnNumber);
                header.addCell(new Column(header, cell, currentRow));
            }
        }
    }

    /**
     * Is this the first iteration?
     * @return boolean <code>true</code> if this is the first iteration
     */
    protected boolean isFirstIteration()
    {
        if (log.isDebugEnabled())
        {
            log.debug("["
                + getUid()
                + "] first iteration="
                + (this.rowNumber == 1)
                + " (row number="
                + this.rowNumber
                + ")");
        }
        // in first iteration this.rowNumber is 1
        // (this.rowNumber is incremented in doAfterBody)
        return this.rowNumber == 1;
    }

    /**
     * When the tag starts, we just initialize some of our variables, and do a little bit of error checking to make sure
     * that the user is not trying to give us parameters that we don't expect.
     * @return int
     * @throws JspException generic exception
     * @see javax.servlet.jsp.tagext.Tag#doStartTag()
     */
    public int doStartTag() throws JspException
    {
        DependencyChecker.check();

        // needed before column processing, elsewhere registered views will not be added
        ExportViewFactory.getInstance();

        if (log.isDebugEnabled())
        {
            log.debug("[" + getUid() + "] doStartTag called");
        }

        this.properties = TableProperties.getInstance((HttpServletRequest) pageContext.getRequest());
        this.tableModel = new TableModel(this.properties, pageContext.getResponse().getCharacterEncoding(), pageContext);

        // copying id to the table model for logging
        this.tableModel.setId(getUid());

        initParameters();

        this.tableModel.setMedia(this.currentMediaType);

        Object previousMediaType = this.pageContext.getAttribute(PAGE_ATTRIBUTE_MEDIA);
        // set the PAGE_ATTRIBUTE_MEDIA attribute in the page scope
        if (previousMediaType == null || MediaTypeEnum.HTML.equals(previousMediaType))
        {
            if (log.isDebugEnabled())
            {
                log.debug("[" + getUid() + "] setting media [" + this.currentMediaType + "] in this.pageContext");
            }
            this.pageContext.setAttribute(PAGE_ATTRIBUTE_MEDIA, this.currentMediaType);
        }

        doIteration();

        // always return EVAL_BODY_TAG to get column headers also if the table is empty
        // using int to avoid deprecation error in compilation using j2ee 1.3
        return 2;
    }

    /**
     * @see javax.servlet.jsp.tagext.BodyTag#doAfterBody()
     */
    public int doAfterBody()
    {
        // doAfterBody() has been called, body is not empty
        this.doAfterBodyExecuted = true;

        if (log.isDebugEnabled())
        {
            log.debug("[" + getUid() + "] doAfterBody called - iterating on row " + this.rowNumber);
        }

        // increment this.rowNumber
        this.rowNumber++;

        // Call doIteration() to do the common work
        return doIteration();
    }

    /**
     * Utility method that is used by both doStartTag() and doAfterBody() to perform an iteration.
     * @return <code>int</code> either EVAL_BODY_TAG or SKIP_BODY depending on whether another iteration is desired.
     */
    protected int doIteration()
    {

        if (log.isDebugEnabled())
        {
            log.debug("[" + getUid() + "] doIteration called");
        }

        // Row already filled?
        if (this.currentRow != null)
        {
            // if yes add to table model and remove
            this.tableModel.addRow(this.currentRow);
            this.currentRow = null;
        }

        if (this.tableIterator.hasNext())
        {

            Object iteratedObject = this.tableIterator.next();
            if (getUid() != null)
            {
                if ((iteratedObject != null))
                {
                    // set object into this.pageContext
                    if (log.isDebugEnabled())
                    {
                        log.debug("[" + getUid() + "] setting attribute \"" + getUid() + "\" in pageContext");
                    }
                    this.pageContext.setAttribute(getUid(), iteratedObject);

                }
                else
                {
                    // if row is null remove previous object
                    this.pageContext.removeAttribute(getUid());
                }
                // set the current row number into this.pageContext
                this.pageContext.setAttribute(getUid() + TableTagExtraInfo.ROWNUM_SUFFIX, new Integer(this.rowNumber));
            }

            // Row object for Cell values
            this.currentRow = new Row(iteratedObject, this.rowNumber);

            this.lastIteration = !this.tableIterator.hasNext();

            // new iteration
            // using int to avoid deprecation error in compilation using j2ee 1.3
            return 2;
        }
        this.lastIteration = true;

        if (log.isDebugEnabled())
        {
            log.debug("[" + getUid() + "] doIteration() - iterator ended after " + (this.rowNumber - 1) + " rows");
        }

        // end iteration
        return SKIP_BODY;
    }

    /**
     * Reads parameters from the request and initialize all the needed table model attributes.
     * @throws FactoryInstantiationException for problems in instantiating a RequestHelperFactory
     */
    private void initParameters() throws JspTagException, FactoryInstantiationException
    {

        if (rhf == null)