Filter 统一全站编码

2014年9月8日10:30:46  

//界面输出中文及中文请求参数（POST方式有效）编码过滤器          

   

    

     package cn.itcast.filter.example;
    
    

      
    
    

     import java.io.IOException;
    
    

      
    
    

     import javax.servlet.Filter;
    
    

     import javax.servlet.FilterChain;
    
    

     import javax.servlet.FilterConfig;
    
    

     import javax.servlet.ServletException;
    
    

     import javax.servlet.ServletRequest;
    
    

     import javax.servlet.ServletResponse;
    
    

      
    
    

     /*
    
    

     web。xml中的配置：
    
    

     

    
    

     <filter>
    
    

       	<filter-name>CharacterSetFilter</filter-name>
    
    

       	<filter-class>cn.itcast.filter.example.CharacterSetFilter</filter-class>
    
    

       	<init-param>
    
    

       		<param-name>encoding</param-name>
    
    

       		<param-value>UTF-8</param-value>
    
    

       	</init-param>
    
    

       </filter>
    
    

       <filter-mapping>
    
    

       	<filter-name>CharacterSetFilter</filter-name>
    
    

       	<url-pattern>/*</url-pattern>
    
    

       </filter-mapping>
    
    

      */
    
   
   

    

   
   

    

     //界面输出中文及中文请求参数（POST方式有效）编码过滤器
    
    

     public class CharacterSetFilter implements Filter {
    
    

     	private FilterConfig filterConfig;
    
    

     	public void destroy() {
    
    

      
    
    

     	}
    
    

      
    
    

     	public void doFilter(ServletRequest request, ServletResponse response,
    
    

     			FilterChain chain) throws IOException, ServletException {
    
    

     		String encodingValue = filterConfig.getInitParameter("encoding");//获取过滤器配置中的参数
    
    

     		if(encodingValue==null)//如果没有配置该参数
    
    

     			encodingValue="UTF-8";//给定默认值UTF-8
    
    

     		request.setCharacterEncoding(encodingValue);//只对POST请求方式有用
    
    

     		response.setContentType("text/html;charset="+encodingValue);
    
    

     		chain.doFilter(request, response);
    
    

     	}
    
    

      
    
    

     	public void init(FilterConfig filterConfig) throws ServletException {
    
    

     		this.filterConfig = filterConfig;
    
    

     	}
    
    

      
    
    

     }
    
   

//数据回显 Servlet          

   

    

     package cn.itcast.servlet;
    
    

      
    
    

     import java.io.IOException;
    
    

     import java.io.PrintWriter;
    
    

      
    
    

     import javax.servlet.ServletException;
    
    

     import javax.servlet.http.HttpServlet;
    
    

     import javax.servlet.http.HttpServletRequest;
    
    

     import javax.servlet.http.HttpServletResponse;
    
    

      
    
    

     public class ServletDemo2 extends HttpServlet {
    
    

      
    
    

     	public void doGet(HttpServletRequest request, HttpServletResponse response)
    
    

     			throws ServletException, IOException {
    
    

     		
    
    

     		//拿到请求参数
    
    

     		String name = request.getParameter("name");
    
    

     		//把拿到的请求参数打印到界面上
    
    

     		PrintWriter out = response.getWriter();
    
    

     		out.write(name);
    
    

     	}
    
    

      
    
    

     	public void doPost(HttpServletRequest request, HttpServletResponse response)
    
    

     			throws ServletException, IOException {
    
    

      
    
    

     		doGet(request, response);
    
    

     	}
    
    

      
    
    

     }
    
   

​# PS：以上方法是将编码的配置封装到了 web.xml 配置文件中。用户只要通过在 .xml 文件中进行相关参数配置，就可以实现统一全站的编码问题了。倘若用户未配置相关参数，则默认编码为"UTF-8".

            ·​

            另外，若只是想进行简单的 统一全站编码，而不需要用户对编码进行设置，则可以直接在 过滤器 Filter 类中设置：request.setCharacterEncoding(”UTF-8“);//只对POST请求方式有用

response.setContentType("text/html;charset=UTF-8");

即可. 免去了再在个各类中编码同样代码的 冗杂性缺陷！

2014年9月8日10:30:46  

//界面输出中文及中文请求参数（POST方式有效）编码过滤器          

    

     

      package cn.itcast.filter.example;
     
     

       
     
     

      import java.io.IOException;
     
     

       
     
     

      import javax.servlet.Filter;
     
     

      import javax.servlet.FilterChain;
     
     

      import javax.servlet.FilterConfig;
     
     

      import javax.servlet.ServletException;
     
     

      import javax.servlet.ServletRequest;
     
     

      import javax.servlet.ServletResponse;
     
     

       
     
     

      /*
     
     

      web。xml中的配置：
     
     

      

     
     

      <filter>
     
     

        	<filter-name>CharacterSetFilter</filter-name>
     
     

        	<filter-class>cn.itcast.filter.example.CharacterSetFilter</filter-class>
     
     

        	<init-param>
     
     

        		<param-name>encoding</param-name>
     
     

        		<param-value>UTF-8</param-value>
     
     

        	</init-param>
     
     

        </filter>
     
     

        <filter-mapping>
     
     

        	<filter-name>CharacterSetFilter</filter-name>
     
     

        	<url-pattern>/*</url-pattern>
     
     

        </filter-mapping>
     
     

       */
     
    
    

     

    
    

     

      //界面输出中文及中文请求参数（POST方式有效）编码过滤器
     
     

      public class CharacterSetFilter implements Filter {
     
     

      	private FilterConfig filterConfig;
     
     

      	public void destroy() {
     
     

       
     
     

      	}
     
     

       
     
     

      	public void doFilter(ServletRequest request, ServletResponse response,
     
     

      			FilterChain chain) throws IOException, ServletException {
     
     

      		String encodingValue = filterConfig.getInitParameter("encoding");//获取过滤器配置中的参数
     
     

      		if(encodingValue==null)//如果没有配置该参数
     
     

      			encodingValue="UTF-8";//给定默认值UTF-8
     
     

      		request.setCharacterEncoding(encodingValue);//只对POST请求方式有用
     
     

      		response.setContentType("text/html;charset="+encodingValue);
     
     

      		chain.doFilter(request, response);
     
     

      	}
     
     

       
     
     

      	public void init(FilterConfig filterConfig) throws ServletException {
     
     

      		this.filterConfig = filterConfig;
     
     

      	}
     
     

       
     
     

      }
     
    

//数据回显 Servlet          

    

     

      package cn.itcast.servlet;
     
     

       
     
     

      import java.io.IOException;
     
     

      import java.io.PrintWriter;
     
     

       
     
     

      import javax.servlet.ServletException;
     
     

      import javax.servlet.http.HttpServlet;
     
     

      import javax.servlet.http.HttpServletRequest;
     
     

      import javax.servlet.http.HttpServletResponse;
     
     

       
     
     

      public class ServletDemo2 extends HttpServlet {
     
     

       
     
     

      	public void doGet(HttpServletRequest request, HttpServletResponse response)
     
     

      			throws ServletException, IOException {
     
     

      		
     
     

      		//拿到请求参数
     
     

      		String name = request.getParameter("name");
     
     

      		//把拿到的请求参数打印到界面上
     
     

      		PrintWriter out = response.getWriter();
     
     

      		out.write(name);
     
     

      	}
     
     

       
     
     

      	public void doPost(HttpServletRequest request, HttpServletResponse response)
     
     

      			throws ServletException, IOException {
     
     

       
     
     

      		doGet(request, response);
     
     

      	}
     
     

       
     
     

      }
     
    

​# PS：以上方法是将编码的配置封装到了 web.xml 配置文件中。用户只要通过在 .xml 文件中进行相关参数配置，就可以实现统一全站的编码问题了。倘若用户未配置相关参数，则默认编码为"UTF-8".

            ·​

            另外，若只是想进行简单的 统一全站编码，而不需要用户对编码进行设置，则可以直接在 过滤器 Filter 类中设置：request.setCharacterEncoding(”UTF-8“);//只对POST请求方式有用

response.setContentType("text/html;charset=UTF-8");

即可. 免去了再在个各类中编码同样代码的 冗杂性缺陷！