FreeMarkerViewResolver.java

package ddth.dasp.hetty.mvc.view.freemarker;

import java.io.IOException;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import ddth.dasp.common.utils.RegExpUtils;
import ddth.dasp.hetty.mvc.view.CacheViewResolver;
import freemarker.cache.TemplateLoader;
import freemarker.template.Configuration;
import freemarker.template.DefaultObjectWrapper;
import freemarker.template.Template;

public class FreeMarkerViewResolver extends CacheViewResolver {

    private final Logger LOGGER = LoggerFactory.getLogger(FreeMarkerViewResolver.class);
    private final static Pattern PATTERN = Pattern.compile("\\@\\{([^}]+)\\}");

    private Configuration cfg;
    private String defaultEncoding = "UTF-8";
    private String defaultContentType = "text/html; charset=utf-8";
    private TemplateLoader templateLoader;
    private String dateFormat = "yyyy-MM-dd";
    private String dateTimeFormat = "yyyy-MM-dd HH:mm:ss";
    private String prefix = "", suffix = "";

    public String getDefaultEncoding() {
        return defaultEncoding;
    }

    public void setDefaultEncoding(String defaultEncoding) {
        this.defaultEncoding = defaultEncoding;
    }

    public String getDefaultContentType() {
        return defaultContentType;
    }

    public void setDefaultContentType(String defaultContentType) {
        this.defaultContentType = defaultContentType;
    }

    public TemplateLoader getTemplateLoader() {
        return templateLoader;
    }

    public void setTemplateLoader(TemplateLoader templateLoader) {
        this.templateLoader = templateLoader;
    }

    public String getDateFormat() {
        return dateFormat;
    }

    public void setDateFormat(String dateFormat) {
        this.dateFormat = dateFormat;
    }

    public String getDateTimeFormat() {
        return dateTimeFormat;
    }

    public void setDateTimeFormat(String dateTimeFormat) {
        this.dateTimeFormat = dateTimeFormat;
    }

    public String getPrefix() {
        return prefix;
    }

    public void setPrefix(String prefix) {
        this.prefix = prefix;
    }

    public String getSuffix() {
        return suffix;
    }

    public void setSuffix(String suffix) {
        this.suffix = suffix;
    }

    public void init() {
        super.init();
        cfg = new Configuration();
        cfg.setObjectWrapper(new DefaultObjectWrapper());
        cfg.setAutoFlush(true);
        cfg.setDefaultEncoding(defaultEncoding);
        cfg.setTemplateLoader(templateLoader);
        cfg.setDateFormat(dateFormat);
        cfg.setDateTimeFormat(dateTimeFormat);
        if (!isEnableCache()) {
            // check for a newer version of a template every time it's requested
            cfg.setTemplateUpdateDelay(0);
        } else {
            cfg.setTemplateUpdateDelay(3600 * 24);
        }
    }

    public void destroy() {
        try {
            cfg = null;
        } finally {
            super.destroy();
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected FreeMarkerView createView(String name, Map<String, String> replacements) {
        String templateName = (prefix != null ? prefix : "") + name
                + (suffix != null ? suffix : "");
        Matcher m = PATTERN.matcher(templateName);
        StringBuffer sb = new StringBuffer();
        while (m.find()) {
            String replacement = replacements != null ? replacements.get(m.group(1)) : "";
            if (replacement == null) {
                replacement = "";
            }
            m.appendReplacement(sb, RegExpUtils.regexpReplacementEscape(replacement));
        }
        m.appendTail(sb);
        templateName = sb.toString();

        Object templateSource = null;
        try {
            templateSource = templateLoader.findTemplateSource(templateName);
            if (templateSource == null) {
                return null;
            }
            Template template = cfg.getTemplate(templateName);
            FreeMarkerView view = new FreeMarkerView(template);
            view.setContentType(getDefaultContentType());
            view.setEncoding(getDefaultEncoding());
            return view;
        } catch (IOException e) {
            throw new RuntimeException(e);
        } finally {
            try {
                templateLoader.closeTemplateSource(templateSource);
            } catch (IOException e) {
                LOGGER.warn(e.getMessage(), e);
            }
        }
    }
}