net.officefloor.plugin.web.http.template.PropertyHttpTemplateWriter.java Source code

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Here is the source code for net.officefloor.plugin.web.http.template.PropertyHttpTemplateWriter.java

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/*
 * OfficeFloor - http://www.officefloor.net
 * Copyright (C) 2005-2013 Daniel Sagenschneider
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package net.officefloor.plugin.web.http.template;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import net.officefloor.plugin.stream.ServerWriter;
import net.officefloor.plugin.value.retriever.ValueRetriever;
import net.officefloor.plugin.web.http.location.HttpApplicationLocation;
import net.officefloor.plugin.web.http.template.parse.PropertyHttpTemplateSectionContent;

import org.apache.commons.lang3.StringEscapeUtils;

/**
 * {@link HttpTemplateWriter} to write a bean property.
 * 
 * @author Daniel Sagenschneider
 */
public class PropertyHttpTemplateWriter implements HttpTemplateWriter {

    /**
     * {@link ValueRetriever}.
     */
    private final ValueRetriever<Object> valueRetriever;

    /**
     * Property name.
     */
    private final String propertyName;

    /**
     * Indicates if the property is to be rendered escaped.
     */
    private final boolean isEscaped;

    /**
     * Initiate.
     * 
     * @param content
     *            {@link PropertyHttpTemplateSectionContent}.
     * @param valueRetriever
     *            {@link ValueRetriever}.
     * @param beanType
     *            Bean type for the property.
     * @throws Exception
     *             If {@link Method} to obtain the value to write is not
     *             available on the bean type.
     */
    public PropertyHttpTemplateWriter(PropertyHttpTemplateSectionContent content,
            ValueRetriever<Object> valueRetriever, Class<?> beanType) throws Exception {
        this.valueRetriever = valueRetriever;
        this.propertyName = content.getPropertyName();

        // Ensure the property is retrievable
        Method method = this.valueRetriever.getTypeMethod(this.propertyName);
        if (method == null) {
            throw new Exception(
                    "Property '" + this.propertyName + "' can not be sourced from bean type " + beanType.getName());
        }

        // Determine if should be escaped
        this.isEscaped = !(method.isAnnotationPresent(UnescapedHtml.class));
    }

    /*
     * ================= HttpTemplateWriter ===============
     */

    @Override
    public void write(ServerWriter writer, boolean isDefaultCharset, Object bean, HttpApplicationLocation location)
            throws IOException {

        // If no bean, then no value to output
        if (bean == null) {
            return;
        }

        // Obtain the property text value
        String propertyTextValue;
        try {

            // Obtain the property value from bean
            Object value = this.valueRetriever.retrieveValue(bean, this.propertyName);

            // Obtain the text value to write as content
            propertyTextValue = (value == null ? "" : value.toString());

        } catch (InvocationTargetException ex) {
            // Propagate cause of method failure
            throw new IOException(ex.getCause());
        } catch (Exception ex) {
            // Propagate failure
            throw new IOException(ex);
        }

        // Write out the value
        if (this.isEscaped) {
            // Write the escaped value
            StringEscapeUtils.ESCAPE_HTML4.translate(propertyTextValue, writer);
        } else {
            // Write the raw value
            writer.write(propertyTextValue);
        }
    }

}