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！