jsp写入中文到mysql乱码问题

记录一下写作业遇到的问题

纠结了很久，代码是用servlet来处理form

其中post传输用户信息时一直乱码，最后查了半天才找见解决方法

 

1. 在jsp页面的<%@ page 位置加上 contentType=”text/html; charset=utf-8″ %>，<meta 的位置也是如此：content=”text/html;charset=utf-8″ />
2. 建立一个mysql数据库,字符集采用utf-8,建表也是如此。
3. 在getConnection的URL中加上：?useUnicode=true&characterEncoding=UTF-8″，如：url = “jdbc:mysql://localhost:3306/(此处为数据库名称)?useUnicode=true&characterEncoding=UTF-8″，也就是在（数据库名称）的后面  //其中问号不能丢
4. 如果你不是在jsp页面里直接处理form，也是和我一样采用servlet来处理form的话，那么在还要增加一个过滤器，这主要是因为采用的是tomcat的web发布器，如果用resin的话，不会有这样的问题。

   package UserSystem.filter;
   
   /**
    * Created by Ruilin on 2017/12/19.
    */
   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;
   import javax.servlet.http.HttpServletRequest;
   import javax.servlet.http.HttpServletRequestWrapper;
   
   public class SetCharacterEncodingFilter implements Filter {
       class Request extends HttpServletRequestWrapper
       {
           public Request(HttpServletRequest request) {
               super(request);
           }
           public String toChi(String input) {
               try {
                   byte[] bytes = input.getBytes("ISO8859-1");
                   return new String(bytes, "utf-8");
               } catch (Exception ex) {
               }
               return null;
           }
           private HttpServletRequest getHttpServletRequest()
           {
               return (HttpServletRequest) super.getRequest();
           }
           public String getParameter(String name)
           {
               return
                       toChi(getHttpServletRequest().getParameter(name));
           }
           public String[] getParameterValues(String name)
           {
               String values[] =getHttpServletRequest().getParameterValues(name);
               if (values != null) {
                   for (int i = 0; i < values.length; i++) {
                       values[i] = toChi(values[i]);
                   }
               }
               return values;
           }
       }
       public void destroy() {
       }
       public void doFilter(ServletRequest request, ServletResponse
               response,FilterChain chain) throws IOException, ServletException {
           HttpServletRequest httpreq = (HttpServletRequest) request;
           if (httpreq.getMethod().equals("POST")) {
               request.setCharacterEncoding("utf-8");
           } else {
               request = new Request(httpreq);
           }
           chain.doFilter(request, response);
       }
       public void init(FilterConfig filterConfig) throws
               ServletException {
       }
   }

   然后在WEB-INF目录下的web.xml文件，配置下过虑器

       <filter>
           <filter-name>SetCharacterEncodingFilter</filter-name>
           <filter-class>UserSystem.filter.SetCharacterEncodingFilter</filter-class>
       </filter>
       <filter-mapping>
           <filter-name>SetCharacterEncodingFilter</filter-name>
           <url-pattern>/*</url-pattern>
       </filter-mapping>

    

 

参考：http://blog.sina.com.cn/s/blog_6c5ad3d10100ligv.html