freemarker 自定义标签

1.

实现自己的自定义 freemarker标签 

package com.f139.frame.freemarker.directive; import java.io.IOException;import java.io.Writer;import java.util.Map; import org.nutz.dao.Dao; import com.f139.frame.pojo.factory.Label; import freemarker.core.Environment;import freemarker.template.TemplateDirectiveBody;import freemarker.template.TemplateDirectiveModel;import freemarker.template.TemplateException;import freemarker.template.TemplateModel; public class LabelDirective implements TemplateDirectiveModel {     private Dao dao;     public LabelDirective(Dao dao) {        this.dao = dao;    }     @Override    @SuppressWarnings("unchecked")    public void execute(Environment env, Map params, TemplateModel[] loopVars, TemplateDirectiveBody body) throws TemplateException, IOException {                 for (TemplateModel templateModel : loopVars) {            templateModel.toString();        }                 // 真正开始处理输出内容        Writer out = env.getOut();         if (body != null) {            out.write(getContent(params));            body.render(out);        }    }     private String getContent(Map<?,?> params) {        Integer id = Integer.parseInt(params.get("id").toString());        if (null != id) {            Label label = this.dao.fetch(Label.class, id);            return label.getLabelContent();        }        return null;    }}

2.将自定义freemarker 标签添加到ExtendServlet 

package com.f139.frame.servlet; import org.nutz.dao.Dao;import org.nutz.dao.impl.NutDao;import org.nutz.ioc.Ioc;import org.nutz.ioc.impl.NutIoc;import org.nutz.ioc.loader.json.JsonLoader; import com.f139.frame.tag.RepeatDirective; import freemarker.ext.jsp.TaglibFactory;import freemarker.ext.servlet.FreemarkerServlet;import freemarker.template.Configuration;import freemarker.template.TemplateModel;import freemarker.template.TemplateModelException;  public class ExtendServlet extends FreemarkerServlet {     /**     *      */    private static final long serialVersionUID = 1L;     private Dao dao;     public ExtendServlet() {        Ioc ioc = new NutIoc(new JsonLoader("com/f139/frame/ioc"));        this.dao = ioc.get(NutDao.class, "dao");    }     @Override    protected Configuration createConfiguration() {        //添加自定义标签        Configuration cfg = super.createConfiguration();        cfg.setSharedVariable("label", new LabelDirective(dao));        return cfg;    } } ExtendServlet继承FreemarkerServlet

3.在web.xml添加相应配置

<servlet>        <servlet-name>freemarker</servlet-name>        <servlet-class>com.f139.frame.servlet.ExtendServlet</servlet-class>        <init-param>            <param-name>TemplatePath</param-name>            <param-value>/</param-value>        </init-param>        <init-param>            <param-name>NoCache</param-name>            <param-value>true</param-value>        </init-param>        <init-param>            <param-name>ContentType</param-name>            <param-value>text/html;charset=UTF-8</param-value>        </init-param>        <init-param>            <param-name>template_update_delay</param-name>            <param-value>0</param-value>        </init-param>        <init-param>            <param-name>default_encoding</param-name>            <param-value>UTF-8</param-value>        </init-param>        <init-param>            <param-name>number_format</param-name>            <param-value>0.##########</param-value>        </init-param>        <load-on-startup>1</load-on-startup>    </servlet>

4.使用自己的标签

<@label id=21> </@label>