几款模板引擎的性能对比

参评的几款模板引擎为：

• XMLTemplate(简称XT)
• Velocity(简称VT)
• CommonTemplate(简称CT)
• FreeMarker(简称FT)
• Smarty4j(简称ST)
• 直接的java代码

性能评测考虑以下几个方面：变量输出/循环/分支，这三大类调用构成了普通模板80%以上的功能。
测试方法为双层循环，输出的中间体是一个空的不执行任何操作的Writer类，
尽可能的减少模板外的性能影响因素，基本的逻辑伪代码描述如下：

for (int i = 0; i < outerTime; i++) {
  for (int j = 0; j < innerTime; j++) {
    testXMLTemplate();
  }
  for (int j = 0; j < innerTime; j++) {
    testVelocityTemplate();
  }
  for (int j = 0; j < innerTime; j++) {
    testCommonTemplate();
  }
  for (int j = 0; j < innerTime; j++) {
    testFreeMarker();
  }
  for (int j = 0; j < innerTime; j++) {
    testSmarty4j();
  }
  for (int j = 0; j < innerTime; j++) {
    testJavaCode();
  }
}

for (int i = 0; i < outerTime; i++) {
  for (int j = 0; j < innerTime; j++) {
    testXMLTemplate();
  }
  for (int j = 0; j < innerTime; j++) {
    testVelocityTemplate();
  }
  for (int j = 0; j < innerTime; j++) {
    testCommonTemplate();
  }
  for (int j = 0; j < innerTime; j++) {
    testFreeMarker();
  }
  for (int j = 0; j < innerTime; j++) {
    testSmarty4j();
  }
  for (int j = 0; j < innerTime; j++) {
    testJavaCode();
  }
}

第一步，测试循环输出ascii码表，各模板引擎文件为

XT:asciitable.xhtml

<div xmlns:c="http://www.xidea.org/ns/template/core">
  <h1>${name}</h1>
  <table border="${border}">
    <tr>
      <th>&#160;</th>
      <c:for var="cell" items="${data}">
      <th>${cell}</th>
      </c:for>
    </tr>
    <c:for var="row" items="${data}">
    <tr>
        <th>${row}</th>
        <c:for var="cell" items="${data}">
          <td><c:out value="&amp;#x"/>${row}${cell};</td>
        </c:for>
    </tr>
    </c:for>
  </table>
</div>

<div xmlns:c="http://www.xidea.org/ns/template/core">
  <h1>${name}</h1>
  <table border="${border}">
    <tr>
      <th>&#160;</th>
      <c:for var="cell" items="${data}">
      <th>${cell}</th>
      </c:for>
    </tr>
    <c:for var="row" items="${data}">
    <tr>
        <th>${row}</th>
        <c:for var="cell" items="${data}">
          <td><c:out value="&amp;#x"/>${row}${cell};</td>
        </c:for>
    </tr>
    </c:for>
  </table>
</div>

VT:asciitable.vm

<div>
<h1>${name}</h1>
<table border="${border}">
 <tr>
  <th>&#160;</th>
#foreach($cell in $data)
  <th>${cell}</th>
#end
 </tr>
#foreach($row in $data)
 <tr>
  <th>${row}</th>
#foreach($cell in $data )
  <td>&#x${row}${cell};</td>
#end
 </tr>
#end
</table>
</div>

<div>
<h1>${name}</h1>
<table border="${border}">
 <tr>
  <th>&#160;</th>
#foreach($cell in $data)
  <th>${cell}</th>
#end
 </tr>
#foreach($row in $data)
 <tr>
  <th>${row}</th>
#foreach($cell in $data )
  <td>&#x${row}${cell};</td>
#end
 </tr>
#end
</table>
</div>

CT:asciitable.ct

<div>
<h1>${name}</h1>
<table border="${border}">
 <tr>
  <th>&#160;</th>
$for{cell:data}
  <th>${cell}</th>
$end
 </tr>
$for{row:data}
 <tr>
  <th>${row}</th>
$for{cell:data}
  <td>&#x${row}${cell};</td>
$end
 </tr>
$end
</table>
</div>

<div>
<h1>${name}</h1>
<table border="${border}">
 <tr>
  <th>&#160;</th>
$for{cell:data}
  <th>${cell}</th>
$end
 </tr>
$for{row:data}
 <tr>
  <th>${row}</th>
$for{cell:data}
  <td>&#x${row}${cell};</td>
$end
 </tr>
$end
</table>
</div>

FT:asciitable.ftl

<div>
<h1>${name}</h1>
<table border="${border}">
 <tr>
  <th>&#160;</th>
<#list data as cell>
  <th>${cell}</th>
</#list>
 </tr>
<#list data as row>
 <tr>
  <th>${row}</th>
<#list data as cell>
  <td>&#x${row}${cell};</td>
</#list>
 </tr>
</#list>
</table>
</div>

<div>
<h1>${name}</h1>
<table border="${border}">
 <tr>
  <th>&#160;</th>
<#list data as cell>
  <th>${cell}</th>
</#list>
 </tr>
<#list data as row>
 <tr>
  <th>${row}</th>
<#list data as cell>
  <td>&#x${row}${cell};</td>
</#list>
 </tr>
</#list>
</table>
</div>

ST:asciitable.html
<div>
<h1>{$name}</h1>
<table border="{$border}">
 <tr>
  <th>&#160;</th>
{section loop=$data name="cell"}
  <th>{$cell}</th>
{/section}
 </tr>
{section loop=$data name="row"}
 <tr>
  <th>{$row}</th>
{section loop=$data name="cell"}
  <td>&#x{$row}{$cell};</td>
{/section}
 </tr>
{/section}
</table>
</div>

ST:asciitable.html
<div>
<h1>{$name}</h1>
<table border="{$border}">
 <tr>
  <th>&#160;</th>
{section loop=$data name="cell"}
  <th>{$cell}</th>
{/section}
 </tr>
{section loop=$data name="row"}
 <tr>
  <th>{$row}</th>
{section loop=$data name="cell"}
  <td>&#x{$row}{$cell};</td>
{/section}
 </tr>
{/section}
</table>
</div>

JAVA:asciitable.java

package org.jside.tt;

import java.io.Writer;
import java.util.List;
import java.util.Map;

public class asciitable implements ICode {

  @Override
  public void execute(Map<String, Object> context, Writer writer) throws Exception {
    List<String> data = (List<String>) context.get("data");
    String name = (String) context.get("name");
    String border = (String) context.get("border");
    writer.write("<div>\n<h1>");
    writer.write(name);
    writer.write("</h1>\n<table border=\"");
    writer.write(border);
    writer.write("\">\n\t<tr>\n\t\t<th>&#160;</th>\n");
    for (String cell : data) {
      writer.write("\t\t<th>");
      writer.write(cell);
      writer.write("</th>\n");
    }
    writer.write("\t</tr>\n");
    for (String row : data) {
      writer.write("\t<tr>\n<th>");
      writer.write(row);
      writer.write("</th>\n");
      for (String cell : data) {
        writer.write("\t\t<td>&#x");
        writer.write(row);
        writer.write(cell);
        writer.write("</td>\n");
      }
      writer.write("\t</tr>\n");
    }
    writer.write("</table>\n</div>\n");
  }

}

package org.jside.tt;

import java.io.Writer;
import java.util.List;
import java.util.Map;

public class asciitable implements ICode {

  @Override
  public void execute(Map<String, Object> context, Writer writer) throws Exception {
    List<String> data = (List<String>) context.get("data");
    String name = (String) context.get("name");
    String border = (String) context.get("border");
    writer.write("<div>\n<h1>");
    writer.write(name);
    writer.write("</h1>\n<table border=\"");
    writer.write(border);
    writer.write("\">\n\t<tr>\n\t\t<th>&#160;</th>\n");
    for (String cell : data) {
      writer.write("\t\t<th>");
      writer.write(cell);
      writer.write("</th>\n");
    }
    writer.write("\t</tr>\n");
    for (String row : data) {
      writer.write("\t<tr>\n<th>");
      writer.write(row);
      writer.write("</th>\n");
      for (String cell : data) {
        writer.write("\t\t<td>&#x");
        writer.write(row);
        writer.write(cell);
        writer.write("</td>\n");
      }
      writer.write("\t</tr>\n");
    }
    writer.write("</table>\n</div>\n");
  }

}

在outerTime=100与innerTime=100时，共循环10000次，平均的结果约是：

=============runing time===============

引用

xt:2149
vt:3499
ct:72254
ft:2761
st:1235
CODE:1321

第二步，在最内层的循环中多输出一个对象，测试新增输出时的性能影响，最内层的那一行改造如下：

XT:
<td>${name}:<c:out value="&amp;#x"/>${row}${cell};</td>
VT:
<td>${name}:&#x${row}${cell};</td>
CT:
<td>${name}:&#x${row}${cell};</td>
FT:
<td>${name}:&#x${row}${cell};</td>
ST:
<td>{$name}:&#x{$row}{$cell};</td>
JAVA:
        writer.write("\t\t<td>");
        writer.write(name);
        writer.write(":&#x");
        writer.write(row);
        writer.write(cell);
        writer.write("</td>\n");

XT:
<td>${name}:<c:out value="&amp;#x"/>${row}${cell};</td>
VT:
<td>${name}:&#x${row}${cell};</td>
CT:
<td>${name}:&#x${row}${cell};</td>
FT:
<td>${name}:&#x${row}${cell};</td>
ST:
<td>{$name}:&#x{$row}{$cell};</td>
JAVA:
        writer.write("\t\t<td>");
        writer.write(name);
        writer.write(":&#x");
        writer.write(row);
        writer.write(cell);
        writer.write("</td>\n");

在outerTime=100与innerTime=100时，共循环10000次，平均的结果约是：
=============runing time===============

引用

xt:3549
vt:4748
ct:103453
ft:4251
st:1750
CODE:1811

第三步，测试分支判断对整体性能的影响，在最内层的循环中输出前加一个分支控制，使它仅输出A-Z对应的ASCII码表，改造如下：

XT:
<td><c:if test="${(row=='4' &amp;&amp; cell!='0') || (row=='5' &amp;&amp; cell&lt;'B')}"><c:out value="&amp;#x"/>${row}${cell};</c:if><c:else><c:out value="&amp;"/>nbsp;</c:else></td>
VT:
<td>#if(($row=="4" && $cell!="0") || ($row=="5" && $cell!="B" && $cell!="C" && $cell!="D" && $cell!="E" && $cell!="F"))&#x${row}${cell};#else&nbsp;#end</td>
CT:
<td>$if{(row=="4" && cell!="0") || (row=="5" && cell<"B")}&#x${row}${cell};$else{}&nbsp;$end</td>
FT:
<td><#if (row?string=="4" && cell?string!="0") || (row?string=='5' && cell?string!='B' && cell?string!='C' && cell?string!='D' && cell?string!='E' && cell?string!='F')>&#x${row}${cell};<#else>&nbsp;</#if></td>
ST:
<td>{if ($row==='4' && $cell!=='0') || ($row==='5' && $cell<'B')}&#x{$row}{$cell};{else}&nbsp;{/if}</td>
JAVA:
        writer.write("\t\t<td>");
        if ((row.equals("4") && !cell.equals("0"))
            || (row.equals("5") && cell.compareTo("B") < 0)) {
          writer.write("&#x");
          writer.write(row);
          writer.write(cell);
        } else {
          writer.write("&nbsp;");
        }
        writer.write("</td>\n");

XT:
<td><c:if test="${(row=='4' &amp;&amp; cell!='0') || (row=='5' &amp;&amp; cell&lt;'B')}"><c:out value="&amp;#x"/>${row}${cell};</c:if><c:else><c:out value="&amp;"/>nbsp;</c:else></td>
VT:
<td>#if(($row=="4" && $cell!="0") || ($row=="5" && $cell!="B" && $cell!="C" && $cell!="D" && $cell!="E" && $cell!="F"))&#x${row}${cell};#else&nbsp;#end</td>
CT:
<td>$if{(row=="4" && cell!="0") || (row=="5" && cell<"B")}&#x${row}${cell};$else{}&nbsp;$end</td>
FT:
<td><#if (row?string=="4" && cell?string!="0") || (row?string=='5' && cell?string!='B' && cell?string!='C' && cell?string!='D' && cell?string!='E' && cell?string!='F')>&#x${row}${cell};<#else>&nbsp;</#if></td>
ST:
<td>{if ($row==='4' && $cell!=='0') || ($row==='5' && $cell<'B')}&#x{$row}{$cell};{else}&nbsp;{/if}</td>
JAVA:
        writer.write("\t\t<td>");
        if ((row.equals("4") && !cell.equals("0"))
            || (row.equals("5") && cell.compareTo("B") < 0)) {
          writer.write("&#x");
          writer.write(row);
          writer.write(cell);
        } else {
          writer.write("&nbsp;");
        }
        writer.write("</td>\n");

考虑到比较的问题，也可以对整个循环进行优化

for (String row : data) {
  char cRow = row.charAt(0);
  writer.write("\t<tr>\n<th>");
  writer.write(row);
  writer.write("</th>\n");
  for (String cell : data) {
    char cCell = cell.charAt(0);
    writer.write("\t\t<td>");
    if ((cRow == '4' && cCell != '0') || (cRow == '5' && cCell < 'B')) {
      writer.write("&#x");
      writer.write(row);
      writer.write(cell);
    } else {
      writer.write("&nbsp;");
    }
    writer.write("</td>\n");
  }
  writer.write("\t</tr>\n");
}

    for (String row : data) {
      char cRow = row.charAt(0);
      writer.write("\t<tr>\n<th>");
      writer.write(row);
      writer.write("</th>\n");
      for (String cell : data) {
        char cCell = cell.charAt(0);
        writer.write("\t\t<td>");
        if ((cRow == '4' && cCell != '0') || (cRow == '5' && cCell < 'B')) {
          writer.write("&#x");
          writer.write(row);
          writer.write(cell);
        } else {
          writer.write("&nbsp;");
        }
        writer.write("</td>\n");
      }
      writer.write("\t</tr>\n");
    }

在outerTime=100与innerTime=100时，共循环10000次，平均的结果约是：

=============runing time===============

引用

xt:3498
vt:2422
ct:153280
ft:7124
st:1142
CODE:1027(优化后940)

结论：
ST在三种常见的模板操作中的表现均极其优秀，除了条件处理效率略低于直接书写的JAVA代码，其它情况下与直接书写JAVA代码效率完全一致，而且在三种操作中，总的执行开销差异非常小。
XT在分支的处理中考虑与JS兼容带来了额外开销，但总体性能仍然占优，只是如果需要过多的XML转义可能影响阅读
FT在分支测试中表现差的原因应该是写法不是最优的，总体来说，性能与VT不相上下
CT的表现最差，在各项操作中均比其它的引擎慢了1-2个数量级

有关的测试代码可以在 http://templatetest.googlecode.com/svn/trunk/ 获得