spring mvc中使用freemark的一点心得

参考文档: FreeMarker标签与使用 连接http://blog.csdn.net/nengyu/article/details/6829244

freemarker学习笔记--指令参考: http://www.cnblogs.com/pengfeisun/articles/1623182.html

Freemarker 高级进阶

jsp的第一次运行,就要运行servlet,如果开发时频繁的修改jsp,会导致开发速度比较慢;(每改一次,要重新编译一次);

编译过后,模板的速度也要比jsp快.

具体的freemark页面上的使用:见http://blog.csdn.net/nengyu/article/details/6829244

最近做的项目中要在spring mvc中实现freemark 加载html模板,关键实现如下:

引入freemark.jar包

web.xml中的配置

    <!--  freemarker 配置 -->
    <bean id="freeMarkerConfigurer"
        class="com.test.common.freemarker.CustomFreeMarkerConfigurer">   <!--freemark的配置文件类-->
        <property name="templateLoaderPaths">
            <list>
            <value>/WEB-INF/template/</value>   <!--html文件的存放位置-->
            </list>
            </property>
        <property name="freemarkerSettings">
            <props>
                <prop key="template_update_delay">5</prop>
                <prop key="default_encoding">UTF-8</prop>
                <prop key="locale">zh_CN</prop>
                <prop key="url_escaping_charset">UTF-8</prop>
                <prop key="date_format">yyyy-MM-dd</prop>
                <prop key="time_format">HH:mm:ss</prop>
                <prop key="datetime_format">yyyy-MM-dd HH:mm:ss</prop>
                <prop key="number_format">0.######</prop>
                <prop key="boolean_format">true,false</prop>
                <prop key="classic_compatible">true</prop>
                <prop key="whitespace_stripping">true</prop>
            </props>
        </property>
    </bean>
    <!-- freemark 页面解析器 -->
    <bean id="viewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.freemarker.FreeMarkerView" />
        <property name="contentType" value="text/html; charset=utf-8" />
        <property name="exposeSpringMacroHelpers" value="true"/>
        <property name="cache" value="true" />
        <property name="suffix" value=".html" />
        <property name="order" value="1" />
    </bean>

配置文件类: com.test.common.freemarker.CustomFreeMarkerConfigurer

public class CustomFreeMarkerConfigurer extends FreeMarkerConfigurer {

    @Override
    protected TemplateLoader getAggregateTemplateLoader(
            List<TemplateLoader> templateLoaders) {
         <!-- HtmlTemplateLoader 这个类用来自定义html模板  -->
        return new HtmlTemplateLoader(super.getAggregateTemplateLoader(templateLoaders));
    }

}

自定义html模板类:HtmlTemplateLoader,加escape  html指令, escape指令在解析模版时起作用，而不是运行时起作用

public class HtmlTemplateLoader implements TemplateLoader {

    private static final String HTML_ESCAPE_PREFIX= "<#escape x as x?html>";
    private static final String HTML_ESCAPE_SUFFIX = "</#escape>";

    private final TemplateLoader delegate;

    public HtmlTemplateLoader(TemplateLoader delegate) {
        this.delegate = delegate;
    }

    /* (non-Javadoc)
     * @see freemarker.cache.TemplateLoader#closeTemplateSource(java.lang.Object)
     */
    @Override
    public void closeTemplateSource(Object templateSource) throws IOException {
        delegate.closeTemplateSource(templateSource);
    }

    /* (non-Javadoc)
     * @see freemarker.cache.TemplateLoader#findTemplateSource(java.lang.String)
     */
    @Override
    public Object findTemplateSource(String name) throws IOException {
        return delegate.findTemplateSource(name);
    }

    /* (non-Javadoc)
     * @see freemarker.cache.TemplateLoader#getLastModified(java.lang.Object)
     */
    @Override
    public long getLastModified(Object templateSource) {
        return delegate.getLastModified(templateSource);
    }

    /* (non-Javadoc)
     * @see freemarker.cache.TemplateLoader#getReader(java.lang.Object, java.lang.String)
     * 在读取template文件之后, 在前后套上<#escape>标签
     */
    @Override
    public Reader getReader(Object templateSource, String encoding) throws IOException {
        Reader reader = delegate.getReader(templateSource, encoding);
        String templateText = IOUtils.toString(reader);
        return new StringReader(HTML_ESCAPE_PREFIX+templateText + HTML_ESCAPE_SUFFIX);
    }

}

escape指令body区的ftl的interpolations都会被自动加上escape表达式。但是不会影响字符串内的interpolations。而且也只会影响到body内出现的interpolations，比如不会影响到include的ftl的interpolations。

<#escape x as x?html>
First name: ${firstName}
Last name: ${lastName}
Maiden name: ${maidenName}
</#escape>
等同于：

First name: ${firstName?html}
Last name: ${lastName?html}
Maiden name: ${maidenName?html}

具体的freemark指令见: freemarker学习笔记--指令参考: http://www.cnblogs.com/pengfeisun/articles/1623182.html