Jiji Ji . . java linux tomcat 301 redirect

web development , the server is tomcat, the system is linux. This domain name without the www want to turn to the band www domain name. Site search out a generation of code, but I do not know how to do .
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made ​​three posts a no knot
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  This reply was moderator deleted at 2012-01-06 17:21:34

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made ​​three posts but could not find an answer .
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this is not simple . tomcat want to bind multiple host names , you can use Alias.
example:
appBase = "webapps"
name = "baidu.com">
www.baodi.com
hi.baidu.com
www.google.com
....



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amount and the minute ?
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301 redirect
301 redirect to achieve the effect : the search engine to index only the new URL , while under the old address will External links shown with the original move to new addresses , so as not to make your site rank as URL changes in affected in the slightest . Similarly, using a 301 permanent redirect command allows multiple domain names point to the main domain site , nor will your site's ranking any negative impact . Therefore, a 301 redirect is the most effective URLs that redirect a way .

  		String requestPage = request.getRequestURI();   
  		String queryString = (request.getQueryString() == null ? "" : "?"+request.getQueryString()); 
  		if(request.getRequestURL().indexOf("http://51chaozhi.com") >=0) {
  			
  			response.setStatus(301);   
  			response.setHeader( "Location", "http://www.51chaozhi.com"+requestPage+queryString);
  			response.setHeader( "Connection", "close" );
  		}

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