Freemarker 自定义标签 实现TemplateDirectiveModel

1 自定义标签需要实现TemplateDirectiveModel这个接口中的execute方法 实例代码如下

public class UserListDirective implements TemplateDirectiveModel{ @Autowired
private UserDAO userDao;
@Override
public void execute(Environment env, Map params, TemplateModel[] loopVars,
TemplateDirectiveBody body)
throws TemplateException, IOException {
String name = params.get("name").toString();
List<User> userlist = userDao.findByProperty("name", name); env.setVariable("userList", getBeansWrapper().wrap(userlist));
body.render(env.getOut());
} public static BeansWrapper getBeansWrapper(){
BeansWrapper beansWrapper =
new BeansWrapperBuilder(Configuration.VERSION_2_3_21).build();
return beansWrapper;
}
}

2 配置 UserListDirective 到spring bean xml中

<bean id="userListDirective" class="com.action.directive.UserListDirective"></bean>

3 将spring bean 设置到freemarkerConfig全局变量中去。

<bean id="freemarkerConfig2"
class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer">
<property name="templateLoaderPath" value="/" />
<property name="freemarkerVariables">
<map >
<entry key="userListDirective" value="userListTag" />
</map>
</property>
<property name="freemarkerSettings">
<props>
<prop key="template_update_delay">0</prop>
<prop key="defaultEncoding">UTF-8</prop>
<prop key="url_escaping_charset">UTF-8</prop>
<prop key="locale">zh_CN</prop>
<prop key="boolean_format">true,false</prop>
<prop key="datetime_format">yyyy-MM-dd HH:mm:ss</prop>
<prop key="date_format">yyyy-MM-dd</prop>
<prop key="time_format">HH:mm:ss</prop>
<prop key="number_format">0.######</prop>
<prop key="whitespace_stripping">true</prop>
</props>
</property>
</bean>

4 ftl文件中的访问方式

<@userListTag name="zhangsan">
<#if userList?? && userList?size gt 0>
<#list userList as user>
<a href="">${user.name}</a>
</#list>
</#if>
</@userListTag>