Spring MVC 4.0 + Velocity Tools 2.0遇到的问题

1、Spring MVC 4.0及更高版本不建议使用Velocity模板引擎，为了继承Velocity并使用Velocity Tools，需要重写viewClass，如下：

import org.apache.velocity.context.Context;
import org.apache.velocity.tools.Scope;
import org.apache.velocity.tools.ToolManager;
import org.apache.velocity.tools.ToolboxFactory;
import org.apache.velocity.tools.view.ViewToolContext;
import org.springframework.web.servlet.view.velocity.VelocityLayoutView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.Map;

public class VelocityLayoutToolbox2View extends VelocityLayoutView {

    private static ToolboxFactory toolboxFactory = null;

    @Override
    protected Context createVelocityContext(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
        // Create a ChainedContext instance.
        ViewToolContext vtc;

        vtc = new ViewToolContext(getVelocityEngine(), request, response, getServletContext());

        vtc.putAll(model);

        if (toolboxFactory == null) {
            ToolManager toolManager = new ToolManager();
            toolManager.setVelocityEngine(getVelocityEngine());
            toolManager.configure(getServletContext().getRealPath(getToolboxConfigLocation()));
            toolboxFactory = toolManager.getToolboxFactory();
        }

        if (this.getToolboxConfigLocation() != null) {
            if (toolboxFactory.hasTools(Scope.REQUEST)) {
                vtc.addToolbox(toolboxFactory.createToolbox(Scope.REQUEST));
            }
            if (toolboxFactory.hasTools(Scope.APPLICATION)) {
                vtc.addToolbox(toolboxFactory.createToolbox(Scope.APPLICATION));
            }
            if (toolboxFactory.hasTools(Scope.SESSION)) {
                vtc.addToolbox(toolboxFactory.createToolbox(Scope.SESSION));
            }
        }
        return vtc;
    }
}

重写后，在applicationContext.xml文件中配置viewClass，如下：

    <bean id="viewResolver" class="org.springframework.web.servlet.view.velocity.VelocityLayoutViewResolver">
        <property name="suffix" value=".html" />
        <property name="cache" value="false" />
        <property name="contentType" value="text/html;charset=utf-8" />
        <!-- 日期函数名称 -->
        <property name="dateToolAttribute" value="date" />
        <!-- 数字函数名称 -->
        <property name="numberToolAttribute" value="number" />
        <property name="layoutUrl" value="layout/default.vm" />
        <property name="viewClass" value="com.acs.survey.util.VelocityLayoutToolbox2View" />
        <property name="toolboxConfigLocation" value="/WEB-INF/velocity-tools.xml" />
    </bean>

2、Velocity Tools 2.0的配置文件格式和低版本的不同，这是个大坑！！！具体如下：
===低版本格式

<toolbox>
    <tool>
        <key>SSOPermission</key>
        <scope>application</scope>
        <class>com.baomidou.springwind.common.SSOPermissionTool</class>
    </tool>
    <tool>
        <key>date</key>
        <scope>application</scope>
        <class>org.apache.velocity.tools.generic.DateTool</class>
    </tool>
    <tool>
        <key>math</key>
        <scope>application</scope>
        <class>org.apache.velocity.tools.generic.MathTool</class>
    </tool>
    <tool>
        <key>number</key>
        <scope>application</scope>
        <class>org.apache.velocity.tools.generic.NumberTool</class>
    </tool>
    <tool>
        <key>render</key>
        <scope>application</scope>
        <class>org.apache.velocity.tools.generic.RenderTool</class>
    </tool>
    <tool>
        <key>esc</key>
        <scope>application</scope>
        <class>org.apache.velocity.tools.generic.EscapeTool</class>
    </tool>
    <tool>
        <key>alternator</key>
        <scope>application</scope>
        <class>org.apache.velocity.tools.generic.AlternatorTool</class>
    </tool>
    <tool>
        <key>parser</key>
        <scope>application</scope>
        <class>org.apache.velocity.tools.generic.ValueParser</class>
    </tool>
    <tool>
        <key>sorter</key>
        <scope>application</scope>
        <class>org.apache.velocity.tools.generic.SortTool</class>
    </tool>
</toolbox>

===2.0格式

<tools>
    <toolbox scope="application">
        <tool class="com.acs.survey.util.PermissionTool" />
        <tool class="org.apache.velocity.tools.generic.DateTool" />
        <tool class="org.apache.velocity.tools.generic.MathTool" />
        <tool class="org.apache.velocity.tools.generic.NumberTool" />
        <tool class="org.apache.velocity.tools.generic.RenderTool" />
        <tool class="org.apache.velocity.tools.generic.EscapeTool" />
        <tool class="org.apache.velocity.tools.generic.AlternatorTool" />
        <tool class="org.apache.velocity.tools.generic.ValueParser" />
        <tool class="org.apache.velocity.tools.generic.SortTool" />
    </toolbox>
    <toolbox scope="request">
        <tool class="org.apache.velocity.tools.view.LinkTool" />
    </toolbox>
</tools>