Velocity在生成模板时，会出现多余的空白和空白行，下面给出2种处理方式：

1. velocity指令之间不要缩进，但是可以换行，在每行后面增加 ## 单行注释指令让velocity引擎放弃解析后面的内容：

#foreach($u in $list) ###if()##
$u.title
###end###end

2. 使用 StructuredGlobbingResourceLoader

This is a structured whitespace globbing implementation that uses an early whitespace filtering while the resource is loaded.

To use it, you would typically put the following lines in your velocity.properties:

resource.loader = globbing,stringglobbing.resource.loader.class = StructuredGlobbingResourceLoaderstring.resource.loader.class = org.apache.velocity.runtime.resource.loader.StringResourceLoader

StructuredGlobbingResourceLoader.java

/* * Copyright 2000-2004 The Apache Software Foundation. * * Licensed under the Apache License, Version 2.0 (the "License") * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * *     http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */package import org.apache.velocity.tools.view;import java.io.FilterInputStream;import java.io.InputStream;import java.io.IOException;public class StructuredGlobbingResourceLoader extends WebappResourceLoader{  public static class VTLIndentationGlobber extends FilterInputStream  {    protected String buffer = "";    protected int bufpos = 0;    protected enum State    {      defstate, hash, comment, directive, schmoo, eol, eof    }    protected State state = State.defstate;      public VTLIndentationGlobber(InputStream is)    {      super(is);    }    // TODO - multiline comments #* ... *# not taken into account for now in all cases    public int read() throws IOException    {      while(true)      {        switch(state)        {          case defstate:          {            int ch = in.read();            switch(ch)            {              case (int)'#':                state = State.hash;                buffer = "";                bufpos = 0;                return ch;              case (int)' ':              case (int)'\t':                buffer += (char)ch;              break;              case -1:                state = State.eof;                break;              default:                buffer += (char)ch;                state = State.schmoo;                break;            }            break;          }          case eol:            if(bufpos < buffer.length()) return (int)buffer.charAt(bufpos++);            else            {              state = State.defstate;              buffer = "";              bufpos = 0;              return '\n';            }          case eof:            if(bufpos < buffer.length()) return (int)buffer.charAt(bufpos++);            else return -1;          case hash:          {            int ch = (int)in.read();            switch(ch)            {              case (int)'#':                state = State.directive;                return ch;              case -1:                state = State.eof;                return -1;              default:                state = State.directive;                buffer = "##";                return ch;            }          }          case directive:          {            int ch = (int)in.read();            if(ch == (int)'\n')            {              state = State.eol;              break;            }            else if (ch == -1)            {              state = State.eof;              break;            }            else return ch;          }          case schmoo:          {            int ch = (int)in.read();            if(ch == (int)'\n')            {              state = State.eol;              break;            }            else if (ch == -1)            {              state = State.eof;              break;            }            else            {              buffer += (char)ch;              return (int)buffer.charAt(bufpos++);            }          }        }      }    }    public int read(byte[] b, int off, int len) throws IOException    {      int i;      int ok = 0;      while (len-- > 0) {        i = read();        if (i == -1) return (ok == 0) ? -1 : ok;        b[off++] = (byte) i;        ok++;      }      return ok;    }    public int read(byte[] b) throws IOException    {      return read(b,0,b.length);    }    public boolean markSupported()    {      return false;    }  }  public synchronized InputStream getResourceStream(String name)  {    return new VTLIndentationGlobber(super.getResourceStream(name));  }  // test  public static void main(String args[])  {    try    {      java.io.BufferedReader reader = new java.io.BufferedReader(new java.io.InputStreamReader(new VTLIndentationGlobber(new java.io.FileInputStream(args[0]))));      String line;      while( (line = reader.readLine() ) != null )      {        System.out.println(line);      }    }    catch(IOException ioe)    {      ioe.printStackTrace();    }  }}