使用GZIP动态压缩Extjs

  比来做的Ext项目Ext的插件都斗劲大，对于网页的浏览速度也是很是不容乐观的，于是就须要对所加载的js文件进行优化，此中一个办法就是对于较大的js文件可以进行紧缩。紧缩成gzjs格局，然则gzjs后缀名的文件又不克不及被浏览器所熟悉，得须要对办事器端做些处理惩罚。 

一、将js格局文件紧缩成gzjs格局。应用gzip.exe打包紧缩后的JS文件，最后生成xx.js.gz，把xx.js.gz文件改成xx.gzjs。紧缩实例： ext-all.js （610KB）， gzip.exe紧缩后为ext-all.gzjs（168KB）。 
附：gzip应用办法，在号令行下输入： gzip -9 ext-all.js ext-all.js.gz 
批改ext-all.js.gz的后缀名ext-all.gzjs（注：也可以经由过程gzip -h号令查看帮助） 
地址：http://www.gzip.org 

    import java.io.IOException;       
    import java.util.HashMap;       
    import java.util.Iterator;       
    import java.util.Map;       
    import javax.servlet.Filter;       
    import javax.servlet.FilterChain;       
    import javax.servlet.FilterConfig;       
    import javax.servlet.ServletException;       
    import javax.servlet.ServletRequest;       
    import javax.servlet.ServletResponse;       
    import javax.servlet.http.HttpServletRequest;       
    import javax.servlet.http.HttpServletResponse;       
    public class GzipJsFilter implements Filter     {      
    	@SuppressWarnings("unchecked")      
    	Map headers = new HashMap();      
    	public void destroy() { }       
    	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)     
    	throws IOException, ServletException {   
    		if (req instanceof HttpServletRequest)   
    			doFilter((HttpServletRequest)req, (HttpServletResponse)res, chain);     
    		else      
    			chain.doFilter(req, res);      }    
    	@SuppressWarnings("unchecked")      
    	public void doFilter(HttpServletRequest request, HttpServletResponse response,       
    			FilterChain chain)      
    	throws IOException, ServletException      
    	{       
    		request.setCharacterEncoding("UTF-8");      
    		for (Iterator it = this.headers.entrySet().iterator(); it.hasNext(); ) {         
    			Map.Entry entry = (Map.Entry)it.next();       
    		response.addHeader((String)entry.getKey(), (String)entry.getValue());       
    		}       
    		chain.doFilter(request, response);      }     
    	@SuppressWarnings("unchecked")      
    	public void init(FilterConfig config) throws ServletException {       
    		String headersStr = config.getInitParameter("headers");      
    		String[] headers = headersStr.split(",");       
    		for (int i = 0; i < headers.length; ++i) {       
    			String[] temp = headers[i].split("=");       
    			this.headers.put(temp[0].trim(), temp[1].trim());      
    			}       
    		}      
    	}     
    <filter>       
    <filter-name>GzipJsFilter</filter-name>      
    <filter-class>com.byd.core.GzipJsFilter</filter-class>  
    <init-param>       
    <param-name>headers</param-name>     
    <param-value>Content-Encoding=gzip</param-value>     
    </init-param>       
    </filter>       
    <filter-mapping>       
    <filter-name>GzipJsFilter</filter-name>       
    <url-pattern>*.gzjs</url-pattern>      
    </filter-mapping>