Velocity在生成模闆時，會出現多餘的空白和空白行，下面給出2種處理方式：
1. velocity指令之間不要縮進，但是可以換行，在每行後面增加## 單行注釋指令讓velocity引擎放棄解析後面的内容：
#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.
This version inherits from org.apache.velocity.tools.view.WebappResourceLoader, but one could easily craft a version inheriting from org.apache.velocity.runtime.resource.loader.FileResourceLoader.
To use it, you would typically put the following lines in your velocity.properties:
resource.loader = globbing,string
globbing.resource.loader.class = StructuredGlobbingResourceLoader
string.resource.loader.class = org.apache.velocity.runtime.resource.loader.StringResourceLoader
StructuredGlobbingResourceLoader.java
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();
}
}
}