com.nec.servlet.view.velocity.VelocityMultipleViewResolver.java Source code

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Here is the source code for com.nec.servlet.view.velocity.VelocityMultipleViewResolver.java

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/**
 * Copyright(C) 2014
 * NEC Corporation All rights reserved.
 * 
 * No permission to use, copy, modify and distribute this software
 * and its documentation for any purpose is granted.
 * This software is provided under applicable license agreement only.
 */
package com.nec.servlet.view.velocity;

import java.util.HashMap;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.servlet.view.AbstractUrlBasedView;
import org.springframework.web.servlet.view.velocity.VelocityLayoutView;
import org.springframework.web.servlet.view.velocity.VelocityViewResolver;

/**
 * Convenience subclass of VelocityViewResolver, adding support for
 * VelocityLayoutView and its properties.
 * 
 * <p>See VelocityViewResolver's javadoc for general usage info.</p>
 * 
 * @author sondn
 * 
 */
public class VelocityMultipleViewResolver extends VelocityViewResolver {

    private static final Logger logger = LoggerFactory.getLogger(VelocityMultipleViewResolver.class);

    private Map<String, String> mappings = new HashMap<String, String>();

    private String layoutKey = VelocityLayoutView.DEFAULT_LAYOUT_KEY;
    private String screenContentKey = VelocityLayoutView.DEFAULT_SCREEN_CONTENT_KEY;

    @Override
    protected Class<?> requiredViewClass() {
        return VelocityLayoutView.class;
    }

    @Override
    protected void initApplicationContext() {
        super.initApplicationContext();
    }

    @Override
    protected AbstractUrlBasedView buildView(final String viewName) throws Exception {
        if (logger.isDebugEnabled()) {
            logger.debug("Building view using multiple layout resolver. View name is {}", viewName);
        }

        VelocityLayoutView view = (VelocityLayoutView) super.buildView(viewName);
        if (layoutKey != null) {
            view.setLayoutKey(layoutKey);
        }

        if (screenContentKey != null) {
            view.setScreenContentKey(screenContentKey);
        }

        if (!this.mappings.isEmpty()) {
            for (Map.Entry<String, String> entry : this.mappings.entrySet()) {
                // Correct wildcards so that we can use the matches method in the String object
                String mappingRegexp = StringUtils.replace(entry.getKey(), "*", ".*");
                // If the view matches the regexp mapping
                if (viewName.matches(mappingRegexp)) {
                    if (logger.isDebugEnabled()) {
                        logger.debug(" Found matching view. Setting layout url to {}", entry.getValue());
                    }

                    view.setLayoutUrl(entry.getValue());
                    return view;
                }
            }
        }

        return view;
    }

    public Map<String, String> getMappings() {
        return mappings;
    }

    public void setMappings(final Map<String, String> mappings) {
        this.mappings = mappings;
    }

    /**
     * Set the context key used to specify an alternate layout to be used instead
     * of the default layout. Screen content templates can override the layout
     * template that they wish to be wrapped with by setting this value in the
     * template, for example:<br>
     * <code>#set( $layout = "MyLayout.html" )</code>
     * <p>The default key is "layout", as illustrated above.
     * @param layoutKey the name of the key you wish to use in your
     * screen content templates to override the layout template
     * @see VelocityLayoutView#setLayoutKey
     * 
     */
    public void setLayoutKey(final String layoutKey) {
        this.layoutKey = layoutKey;
    }

    /**
     * Set the name of the context key that will hold the content of
     * the screen within the layout template. This key must be present
     * in the layout template for the current screen to be rendered.
     * <p>Default is "screen_content": accessed in VTL as
     * <code>$screen_content</code>.
     * @param screenContentKey the name of the screen content key to use
     * @see VelocityLayoutView#setScreenContentKey
     * 
     */
    public void setScreenContentKey(final String screenContentKey) {
        this.screenContentKey = screenContentKey;
    }

}