formtag.java

这是一个轻便的j2ee的web应用框架,是一个在多个项目中运用的实际框架,采用struts,hebinate,xml等技术,有丰富的tag,role,navigation,session,dictio

	 */
	public String getTarget() {

		return (this.target);

	}

	/**
	 * Set the window target.
	 *
	 * @param target The new window target
	 */
	public void setTarget(String target) {

		this.target = target;

	}

	/**
	 * Return the Java class of our bean.
	 */
	public String getType() {

		return (this.type);

	}

	/**
	 * Set the Java class of our bean.
	 *
	 * @param type The new Java class
	 */
	public void setType(String type) {

		this.type = type;

	}

	public String getValidate() {
		return this.validate;
	}

	public void setValidate(String validate) {
		this.validate = validate;
	}

	// --------------------------------------------------------- Public Methods

	/**
	 * Render the beginning of this form.
	 *
	 * @exception JspException if a JSP exception has occurred
	 */
	public int doStartTag() throws JspException {

		// Look up the form bean name, scope, and type if necessary
		//this.lookup();

		// Create an appropriate "form" element based on our parameters
		StringBuffer results = new StringBuffer();

		results.append(this.renderFormStartElement());

		results.append(this.renderToken());

		ResponseUtils.write(pageContext, results.toString());

		// Store this tag itself as a page attribute
		pageContext.setAttribute(
			Constants.FORM_KEY,
			this,
			PageContext.REQUEST_SCOPE);

		//this.initFormBean();

		return (EVAL_BODY_INCLUDE);

	}

	/**
	 * Locate or create the bean associated with our form.
	 * @throws JspException
	 * @since Struts 1.1
	 */
	protected void initFormBean() throws JspException {
		int scope = PageContext.SESSION_SCOPE;
		if ("request".equalsIgnoreCase(beanScope)) {
			scope = PageContext.REQUEST_SCOPE;
		}

		Object bean = pageContext.getAttribute(beanName, scope);
		if (bean == null) {
			if (type != null) {
				// Backwards compatibility - use explicitly specified values
				try {
					bean = RequestUtils.applicationInstance(beanType);
					if (bean != null) {
						((ActionForm) bean).setServlet(servlet);
					}
				} catch (Exception e) {
					throw new JspException(
						messages.getMessage(
							"formTag.create",
							type,
							e.toString()));
				}
			} else {
				// New and improved - use the values from the action mapping
				bean =
					RequestUtils.createActionForm(
						(HttpServletRequest) pageContext.getRequest(),
						mapping,
						moduleConfig,
						servlet);
			}
			if (bean instanceof ActionForm) {
				((ActionForm) bean).reset(
					mapping,
					(HttpServletRequest) pageContext.getRequest());
			}
			if (bean == null) {
				throw new JspException(
					messages.getMessage("formTag.create", beanType));
			}
			pageContext.setAttribute(beanName, bean, scope);
		}
		pageContext.setAttribute(
			Constants.BEAN_KEY,
			bean,
			PageContext.REQUEST_SCOPE);
	}

	/**
	 * Generates the opening <code>&lt;form&gt;</code> element with appropriate
	 * attributes.
	 * @since Struts 1.1
	 */
	protected String renderFormStartElement() {
		HttpServletResponse response =
			(HttpServletResponse) this.pageContext.getResponse();

		StringBuffer results = new StringBuffer("<form");
		results.append(" name=\"");
		results.append(name);
		results.append("\"");
		results.append(" method=\"");
		results.append(method == null ? "post" : method);
		results.append("\" action=\"");
		results.append(
			response.encodeURL(
				RequestUtils.getActionMappingURL(
					this.action,
					this.pageContext)));

		results.append("\"");

		if (styleClass != null) {
			results.append(" class=\"");
			results.append(styleClass);
			results.append("\"");
		}
		if (enctype != null) {
			results.append(" enctype=\"");
			results.append(enctype);
			results.append("\"");
		}
		if (onreset != null) {
			results.append(" onreset=\"");
			results.append(onreset);
			results.append("\"");
		}
		if (onsubmit != null) {
			results.append(" onsubmit=\"");
			results.append(onsubmit);
			results.append("\"");
		}
		if (style != null) {
			results.append(" style=\"");
			results.append(style);
			results.append("\"");
		}
		if (styleId != null) {
			results.append(" id=\"");
			results.append(styleId);
			results.append("\"");
		}
		if (target != null) {
			results.append(" target=\"");
			results.append(target);
			results.append("\"");
		}
		if ( validate!=null &&  validate.equals( VALIDATE_ENABLE) ) {
			results.append(" onSubmit=\"");
			results.append(" return validate(this);");
			results.append("\"");
		}
		
		results.append(">");
		return results.toString();
	}

	/**
	 * Generates a hidden input field with token information, if any.
	 * @return A hidden input field containing the token.
	 * @since Struts 1.1
	 */
	protected String renderToken() {
		StringBuffer results = new StringBuffer();
		HttpSession session = pageContext.getSession();

		if (session != null) {
			String token =
				(String) session.getAttribute(Globals.TRANSACTION_TOKEN_KEY);

			if (token != null) {
				results.append("<input type=\"hidden\" name=\"");
				results.append(Constants.TOKEN_KEY);
				results.append("\" value=\"");
				results.append(token);
				if (this.isXhtml()) {
					results.append("\" />");
				} else {
					results.append("\">");
				}
			}
		}

		return results.toString();
	}

	/**
	 * Render the end of this form.
	 *
	 * @exception JspException if a JSP exception has occurred
	 */
	public int doEndTag() throws JspException {

		// Remove the page scope attributes we created
		pageContext.removeAttribute(
			Constants.BEAN_KEY,
			PageContext.REQUEST_SCOPE);
		pageContext.removeAttribute(
			Constants.FORM_KEY,
			PageContext.REQUEST_SCOPE);

		// Render a tag representing the end of our current form
		StringBuffer results = new StringBuffer("</form>");

		// Render JavaScript to set the input focus if required
		if (this.focus != null) {
			results.append(this.renderFocusJavascript());
		}

		// Print this value to our output writer
		JspWriter writer = pageContext.getOut();
		try {
			writer.print(results.toString());
		} catch (IOException e) {
			throw new JspException(
				messages.getMessage("common.io", e.toString()));
		}

		// Continue processing this page
		return (EVAL_PAGE);

	}

	/**
	 * Generates javascript to set the initial focus to the form element given in the
	 * tag's "focus" attribute.
	 * @since Struts 1.1
	 */
	protected String renderFocusJavascript() {
		StringBuffer results = new StringBuffer();

		results.append(lineEnd);
		results.append("<script type=\"text/javascript\"");
		if (!this.isXhtml()) {
			results.append(" language=\"JavaScript\"");
		}
		results.append(">");
		results.append(lineEnd);

		// xhtml script content shouldn't use the browser hiding trick
		if (!this.isXhtml()) {
			results.append("  <!--");
			results.append(lineEnd);
		}

		// Construct the control name that will receive focus.
		// This does not include any index.
		StringBuffer focusControl = new StringBuffer("document.forms[\"");
		focusControl.append(beanName);
		focusControl.append("\"].elements[\"");
		focusControl.append(this.focus);
		focusControl.append("\"]");

		results.append("  var focusControl = ");
		results.append(focusControl.toString());
		results.append(";");
		results.append(lineEnd);
		results.append(lineEnd);

		results.append("  if (focusControl.type != \"hidden\") {");
		results.append(lineEnd);

		// Construct the index if needed and insert into focus statement
		String index = "";
		if (this.focusIndex != null) {
			StringBuffer sb = new StringBuffer("[");
			sb.append(this.focusIndex);
			sb.append("]");
			index = sb.toString();
		}
		results.append("     focusControl");
		results.append(index);
		results.append(".focus();");
		results.append(lineEnd);

		results.append("  }");
		results.append(lineEnd);

		if (!this.isXhtml()) {
			results.append("  // -->");
			results.append(lineEnd);
		}

		results.append("</script>");
		results.append(lineEnd);
		return results.toString();
	}

	/**
	 * Release any acquired resources.
	 */
	public void release() {

		super.release();
		action = null;
		moduleConfig = null;
		enctype = null;
		focus = null;
		focusIndex = null;
		mapping = null;
		method = null;
		name = null;
		onreset = null;
		onsubmit = null;
		scope = null;
		servlet = null;
		style = null;
		styleClass = null;
		styleId = null;
		target = null;
		type = null;

	}

	// ------------------------------------------------------ Protected Methods

	/**
	 * Look up values for the <code>name</code>, <code>scope</code>, and
	 * <code>type</code> properties if necessary.
	 *
	 * @exception JspException if a required value cannot be looked up
	 */
	protected void lookup() throws JspException {

		// Look up the module configuration information we need
		moduleConfig = RequestUtils.getModuleConfig(pageContext);

		if (moduleConfig == null) {
			JspException e =
				new JspException(messages.getMessage("formTag.collections"));
			pageContext.setAttribute(
				Globals.EXCEPTION_KEY,
				e,
				PageContext.REQUEST_SCOPE);
			throw e;
		}
		servlet =
			(ActionServlet) pageContext.getServletContext().getAttribute(
				Globals.ACTION_SERVLET_KEY);

		// Look up the action mapping we will be submitting to
		String mappingName = RequestUtils.getActionMappingName(action);
		mapping = (ActionMapping) moduleConfig.findActionConfig(mappingName);
		if (mapping == null) {
			JspException e =
				new JspException(
					messages.getMessage("formTag.mapping", mappingName));
			pageContext.setAttribute(
				Globals.EXCEPTION_KEY,
				e,
				PageContext.REQUEST_SCOPE);
			throw e;
		}

		// Were the required values already specified?
		if (name != null) {
			if (type == null) {
				JspException e =
					new JspException(messages.getMessage("formTag.nameType"));
				pageContext.setAttribute(
					Globals.EXCEPTION_KEY,
					e,
					PageContext.REQUEST_SCOPE);
				throw e;
			}
			beanName = name;
			beanScope = (scope == null ? "session" : scope);
			beanType = type;
			return;
		}

		// Look up the form bean definition
		FormBeanConfig formBeanConfig =
			moduleConfig.findFormBeanConfig(mapping.getName());
		if (formBeanConfig == null) {
			JspException e =
				new JspException(
					messages.getMessage("formTag.formBean", mapping.getName()));
			pageContext.setAttribute(
				Globals.EXCEPTION_KEY,
				e,
				PageContext.REQUEST_SCOPE);
			throw e;
		}

		// Calculate the required values
		beanName = mapping.getAttribute();
		beanScope = mapping.getScope();
		beanType = formBeanConfig.getType();
	}

	/**
	 * Returns true if this tag should render as xhtml.
	 */
	private boolean isXhtml() {
		return RequestUtils.isXhtml(this.pageContext);
	}

	/**
	 * Returns the focusIndex.
	 * @return String
	 */
	public String getFocusIndex() {
		return focusIndex;
	}

	/**
	 * Sets the focusIndex.
	 * @param focusIndex The focusIndex to set
	 */
	public void setFocusIndex(String focusIndex) {
		this.focusIndex = focusIndex;
	}

}