Examples of JspWriter

javax.servlet.jsp.JspWriter
The actions and template data in a JSP page is written using the JspWriter object that is referenced by the implicit variable out which is initialized automatically using methods in the PageContext object.
This abstract class emulates some of the functionality found in the java.io.BufferedWriter and java.io.PrintWriter classes, however it differs in that it throws java.io.IOException from the print methods while PrintWriter does not.
Buffering
The initial JspWriter object is associated with the PrintWriter object of the ServletResponse in a way that depends on whether the page is or is not buffered. If the page is not buffered, output written to this JspWriter object will be written through to the PrintWriter directly, which will be created if necessary by invoking the getWriter() method on the response object. But if the page is buffered, the PrintWriter object will not be created until the buffer is flushed and operations like setContentType() are legal. Since this flexibility simplifies programming substantially, buffering is the default for JSP pages.
Buffering raises the issue of what to do when the buffer is exceeded. Two approaches can be taken:
- Exceeding the buffer is not a fatal error; when the buffer is exceeded, just flush the output.
- Exceeding the buffer is a fatal error; when the buffer is exceeded, raise an exception.
Both approaches are valid, and thus both are supported in the JSP technology. The behavior of a page is controlled by the autoFlush attribute, which defaults to true. In general, JSP pages that need to be sure that correct and complete data has been sent to their client may want to set autoFlush to false, with a typical case being that where the client is an application itself. On the other hand, JSP pages that send data that is meaningful even when partially constructed may want to set autoFlush to true; such as when the data is sent for immediate display through a browser. Each application will need to consider their specific needs.
An alternative considered was to make the buffer size unbounded; but, this had the disadvantage that runaway computations would consume an unbounded amount of resources.
The "out" implicit variable of a JSP implementation class is of this type. If the page directive selects autoflush="true" then all the I/O operations on this class shall automatically flush the contents of the buffer if an overflow condition would result if the current operation were performed without a flush. If autoflush="false" then all the I/O operations on this class shall throw an IOException if performing the current operation would result in a buffer overflow condition. @see java.io.Writer @see java.io.BufferedWriter @see java.io.PrintWriter

Examples of javax.servlet.jsp.JspWriter

     * @see net.sf.jportlet.web.taglib.BaseTag#doStartHtml(javax.servlet.http.HttpServletRequest)
     */
    protected int doStartHtml( HttpServletRequest request )
        throws IOException
    {
    JspWriter out = pageContext.getOut(  );
    
    out.write( "<td valign='top'" );
     
    outputCss();
    
    if ( _width != null )
    {
      out.write( " width='" +  _width + "'");
    }
    
        out.write( "><table width='100%' border='0' cellspacing='0' cellpadding='0'>\n" );
        return EVAL_BODY_INCLUDE;
    }

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Examples of javax.servlet.jsp.JspWriter

        String ctx = ((HttpServletRequest)(pageContext.getRequest())).getContextPath();
        Preferences prefs = Preferences.systemRoot().node("net/sourceforge/geekblog" + ctx);


        String headshots = prefs.get("weblog.headshotsdir", "images");
        Set headshotsDir = pageContext.getServletContext().getResourcePaths(headshots);
        JspWriter out = pageContext.getOut();


        System.err.println(headshotsDir);
        String[] fileList = (String[]) headshotsDir.toArray(new String[0]);


        try
        {
            if (fileList.length == 1)
                out.write(fileList[0]);
            else
            {
                int choice = (int) (Math.random() * fileList.length);
                out.write(fileList[choice]);
            }
        }
        catch(IOException e)
        {}
        return EVAL_BODY_INCLUDE;

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Examples of javax.servlet.jsp.JspWriter

            param = new ParamElement(GraphAppletParameters.SCALE_UP,
                    graphConfig.isScaleUp());
            applet.addChildElement(param);
        }


        final JspWriter writer = pageContext.getOut();


        try {
            writer.println(applet.toString());
        } catch (IOException e) {
            throw new JspException(e);
        }
        return SKIP_BODY;
    }

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Examples of javax.servlet.jsp.JspWriter


    private void addHiddenFields()
        throws JspException{
        try {
            final ServletRequest request = pageContext.getRequest();
            final JspWriter writer = pageContext.getOut();
            String applicationId =
                    request.getParameter(RequestParams.APPLICATION_ID);
            if(applicationId != null){
                writer.println();
                writer.print(HIDDEN_FIELD_APP_ID_BEGIN);
                writer.print(applicationId);
                writer.println(HIDDEN_FIELD_END);
            }
            String objectName =
                    request.getParameter(RequestParams.OBJECT_NAME);
            if(objectName != null){
                writer.print(HIDDEN_FIELD_OBJECT_NAME_BEGIN);
                writer.print(StringUtils.htmlEscape(objectName));
                writer.println(HIDDEN_FIELD_END);
            }


        } catch (IOException e) {
            throw new JspException(e);
        }

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Examples of javax.servlet.jsp.JspWriter

        }
        results.append("</form>");
        if (this.focus != null && !this.focus.equals("")) {
            results.append(this.renderFocusJavascript());
        }
        JspWriter writer = pageContext.getOut();
        try {
            writer.print(results.toString());
        } catch (IOException e) {
            throw new JspException(messages.getMessage("common.io", e.toString()));
        }
        return (EVAL_PAGE);
    }

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Examples of javax.servlet.jsp.JspWriter

            else {                
                out = new JspWriterAdapter(out);
                pageContext.pushWriter((JspWriter)out);
                usesAdapter = true;
            }
            JspWriter w = new TagWriter(out, tag, pageContext, usesAdapter);
            pageContext.pushTopTag(tag);
            pageContext.pushWriter(w);
            return w;
        }
        catch(TemplateModelException e) {

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Examples of javax.servlet.jsp.JspWriter

     * @param data The data to write out to the page
     * @throws JspException
     */
    public static void writeOutput(PageContext context, String data)
            throws JspException {
        JspWriter writer = context.getOut();
        try {
            writer.print(data);
        } catch (Exception e) {
            throw new JspException(
                    "Failure writing to pageContext.  Exception = " //$NON-NLS-1$
                            + e.getMessage(), e);
        }

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Examples of javax.servlet.jsp.JspWriter

    throws JspException
  {
    try {
      PageContextImpl pageContext = (PageContextImpl) this.pageContext;
      
      JspWriter out = pageContext.getOut();


      TransformerFactory factory = TransformerFactory.newInstance();


      String xsltSystemId = getCanonicalURL(pageContext, _xsltSystemId);

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Examples of javax.servlet.jsp.JspWriter

  {
    String value = encodeURL(pageContext, _url);


    try {
      if (_var == null) {
        JspWriter out = pageContext.getOut();


        out.print(value);
      }
      else
        CoreSetTag.setValue(pageContext, _var, _scope, value);
    } catch (IOException e) {
      throw new JspException(e);

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Examples of javax.servlet.jsp.JspWriter

    throws JspException
  {
    try {
      PageContextImpl pc = (PageContextImpl) pageContext;
      
      JspWriter out = pc.getOut();


      NumberFormat format = getFormat();


      Double rawValue = null;
      BodyContentImpl body = (BodyContentImpl) getBodyContent();


      if (_hasValue)
        rawValue = _value;
      else if (body != null) {
        String value = body.getTrimString();


        if (! value.equals(""))
          rawValue = Double.parseDouble(value);
      }


      if (rawValue != null && Double.isNaN(rawValue))
        rawValue = 0.0;


      String value;


      if (rawValue == null)
        value = null;
      else if (format != null)
        value = format.format(rawValue);
      else
        value = String.valueOf(rawValue);


      if (_var == null) {
        if (_scope != null)
          throw new JspException(L.l("fmt:formatDate var must not be null when scope '{0}' is set.",
                                     _scope));


        if (value != null)
          out.print(value);
      }
      else
        CoreSetTag.setValue(pageContext, _var, _scope, value);
    } catch (IOException e) {
    }

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