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！