onetomanycrudcontroller.java

一个很好的开源项目管理系统源代码

    /**
     * Adds a new row to the collection. Note that no call to the service layer
     * is made.
     * @param request The request
     * @param response The response
     * @param command The command object
     * @param errors The bind Exception
     * @return model and view
     * @throws Exception
     */
    protected ModelAndView addRow(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
            throws Exception {
        if (logger.isInfoEnabled())
            logger.info("addRow() invoked.");
        List list = (List) PropertyUtils.getSimpleProperty(command,
                collectionPropertyName);

        Object element = collectionElementClass.newInstance();
        if (logger.isInfoEnabled())
            logger.info("element of type " + element.getClass()
                    + " added to collection " + collectionPropertyName);
        
        PropertyUtils.setSimpleProperty(element, "processType", "insert");
        list.add(element);
        // skip any errors
        request.setAttribute(SKIP_ERRORS, "skip");
        return showForm(request, response, errors);
    }

    /**
     * Removes the ignored row from the collection. Note that no call to the
     * service layer is made.
     * @param request The request
     * @param response The response
     * @param command The command object
     * @param errors The bind Exception
     * @return model and view
     * @throws Exception
     */
    protected ModelAndView ignoreRow(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
            throws Exception {
        if (logger.isInfoEnabled())
            logger.info("ignoreRow() invoked.");
        // remove the ignored row from the collection.
        List list = (List) PropertyUtils.getSimpleProperty(command,
                collectionPropertyName);
        Iterator it = list.iterator();
        while (it.hasNext()) {
            CollectionElement row = (CollectionElement) it.next();
            if (IGNORE.equals(row.getProcessType())) {
                it.remove();
            }
        }
        // skip any errors
        request.setAttribute(SKIP_ERRORS, "skip");
        return showForm(request, response, errors);
    }

    /**
     * Save object. Processes exceptions OptimisticLockingException,
     * UniqueConstraintException and NoParentRowFkException, IPropertyException.
     * Also stores a transaction token in session and saves a success message in
     * message queue for jsps.
     * @param request The request
     * @param response The response
     * @param command The command object
     * @param errors The bind exception
     * @return ModelAndView the model and view
     * @throws Exception
     */
    protected ModelAndView save(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
            throws Exception {
        if (logger.isInfoEnabled())
            logger.info("save() invoked.");

        try {
            saveMethod.invoke(service, new Object[] { command });
            saveMessage(request, "save.success");
            // to prevent duplicate submissions create a new token
            saveToken(request);
            return showForm(request, response, errors);
        }
        catch (InvocationTargetException ite) {
            Throwable t = ite.getTargetException();
            if (t instanceof OptimisticLockingException) {
                errors.reject(((OptimisticLockingException) t).getErrorCode());
                return showForm(request, response, errors);
            }
            else if (t instanceof UniqueConstraintException) {
                populatePropertyErrors(errors, (IPropertyException) t);
                return showFormWhenException(request, response, command, errors);
            }
            else if (t instanceof NoParentRowFkException) {
                populatePropertyErrors(errors, (IPropertyException) t);
                return showFormWhenException(request, response, command, errors);
            }
            else if (t instanceof IPropertyException) {
                populatePropertyErrors(errors, (IPropertyException) t);
                return showFormWhenException(request, response, command, errors);
            }
            else
                throw (Exception) t;
        }
    }

    /**
     * Gets the object from the service layer. Also saves a ViewHelper for the
     * jsps to help render the view appropriately and transaction token to
     * prevent multiple submits.
     * @param request the http request
     * @param pk The primary key
     * @return The object
     */
    protected Object getObject(HttpServletRequest request, Object pk) {
        if (logger.isInfoEnabled())
            logger.info("getObject invoked.");
        try {
            Object result = getObjectMethod
                    .invoke(service, new Object[] { pk });
            saveViewHelper(request, ViewHelper.SUBMIT_MODE);
            // initialize the synchronizer token. Is used in submit
            // processing to prevent duplicate submits
            saveToken(request);
            return result;
        }
        catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Starts the flow which will set the value for a field. Stores a
     * <code>FlowSetValueHelper</code> in users session. Expects to find the
     * following parameters in the request: COLLECTION_IDX,
     * TARGET_PROPERTY_NAME_FOR_VALUE, SUB_FLOW
     * @param request the request
     * @param response the response
     * @param command the command
     * @param errors the bind exception
     * @return @throws Exception
     */
    protected ModelAndView startFlowSetValue(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
            throws Exception {
        if (logger.isInfoEnabled())
            logger.info("startFlowSetValue() invoked.");

        String collectionIdx = request.getParameter(COLLECTION_IDX);
        Validate.notEmpty(collectionIdx,
                "http request parameter 'collectionIdx' cannot be null");

        String targetPropertyNameForValue = request
                .getParameter(TARGET_PROPERTY_NAME_FOR_VALUE);
        Validate
                .notEmpty(targetPropertyNameForValue,
                        "http request parameter 'targetPropertyNameForValue' cannot be null");

        String subFlow = request.getParameter(SUB_FLOW);

        Validate.notEmpty(collectionIdx,
                "http request parameter 'subFlow' cannot be null");

        if (logger.isInfoEnabled()) {
            logger.info(COLLECTION_IDX + "=" + collectionIdx);
            logger.info(TARGET_PROPERTY_NAME_FOR_VALUE + "="
                    + targetPropertyNameForValue);
            logger.info(SUB_FLOW + "=" + subFlow);
        }

        FlowSetValueHelper flowHelper = new FlowSetValueHelper(collectionIdx,
                targetPropertyNameForValue, (String) request.getSession()
                        .getAttribute(TOKEN_ATTRIBUTE_NAME));

        request.getSession().setAttribute(getFlowSetValueHelperAttributeName(),
                flowHelper);

        // store the command object in the session and redirect to the subflow
        // controller
        request.getSession().setAttribute(getFormSessionAttributeName(),
                command);
        return new ModelAndView(getView(request, subFlow));
    }

    /**
     * Cancels the flow which has started to set a value of a field.
     * @param request the request
     * @param response the response
     * @param command the command
     * @param errors the bind exception
     * @return @throws Exception
     */
    protected ModelAndView cancelFlowSetValue(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
            throws Exception {
        if (logger.isInfoEnabled())
            logger.info("cancelFlowSetValue() invoked.");
        FlowSetValueHelper flowHelper = (FlowSetValueHelper) request
                .getSession()
                .getAttribute(getFlowSetValueHelperAttributeName());
        // Make sure the current token is same as token in helper.
        String token = request.getParameter(TOKEN_PARAMETER_NAME);
        Validate.notEmpty(token,
                "The transaction token not available in the http request");
        // The token could have changed since the flow helper was last stored in
        // session. Make sure the token is valid
        if (!token.equals(flowHelper.getToken()))
            throw new InvalidSynchronizerTokenException(
                    "transaction token mismatch with flow helper");
        request.getSession().removeAttribute(
                getFlowSetValueHelperAttributeName());
        // create new BindException so that no bind errors are shown
        return showForm(request, response, createNewBindException(request,
                command, getCommandName()));
    }

    /**
     * Assigns the selected value to the target collection element. Expects the
     * parameter SELECTED_VALUE to be in the request. Also makes sure the
     * transaction token is valid
     * @param request The request
     * @param response The response
     * @param command The command
     * @param errors The bind exception
     * @return @throws Exception
     */
    protected ModelAndView assignSelectedValue(HttpServletRequest request,
            HttpServletResponse response, Object command, BindException errors)
            throws Exception {
        if (logger.isInfoEnabled())
            logger.info("assignSelectedValue() invoked.");
        FlowSetValueHelper flowHelper = (FlowSetValueHelper) request
                .getSession()
                .getAttribute(getFlowSetValueHelperAttributeName());

        Validate.notNull(flowHelper, "Could not find flow helper in session:"
                + getFlowSetValueHelperAttributeName());

        // Make sure the current token is same as token in helper.
        String token = request.getParameter(TOKEN_PARAMETER_NAME);
        Validate.notEmpty(token,
                "The transaction token not available in the http request");

        // The token could have changed since the flow helper was last stored in
        // session. Make sure the token is valid
        if (!token.equals(flowHelper.getToken()))
            throw new InvalidSynchronizerTokenException(
                    "transaction token mismatch with flow helper");

        List list = (List) PropertyUtils.getSimpleProperty(command,
                collectionPropertyName);

        Object element = list.get(new Integer(flowHelper.getCollectionIdx())
                .intValue());

        String selectedValue = request.getParameter(SELECTED_VALUE);
        Validate.notEmpty(selectedValue,
                "'selectedValue' parameter not available in the http request");

        if (String.class.equals(PropertyUtils.getPropertyType(element,
                flowHelper.getTargetPropertyNameForValue()))) {
            PropertyUtils.setSimpleProperty(element, flowHelper
                    .getTargetPropertyNameForValue(), selectedValue);
        }
        else {
            //the assumption is if property being set is not a String it is a
            // Long.
            //TODO fix this
            PropertyUtils.setSimpleProperty(element, flowHelper
                    .getTargetPropertyNameForValue(), new Long(selectedValue));
        }

        // create a new BindException to override any bind exceptions created
        // during binding
        return showForm(request, response, createNewBindException(request,
                command, getCommandName()));
    }

    /**
     * get the view for the page which will be used to select a value
     * @param request The request
     * @param subFlow The sub flow url.
     * @return the view
     */
    private String getView(HttpServletRequest request, String subFlow) {
        if (subFlow.indexOf('?') != -1)
            return "redirect:" + subFlow + "&parentFlow="
                    + getControllerPath(request);
        else
            return "redirect:" + subFlow + "?parentFlow="
                    + getControllerPath(request);
    }

}