JSP乱码问题

1。设置JSP页面编码：

<%@ page contentType="text/html;charset=UTF-8" language="java"%>

2。设置request 编码方式：

写一个类filter,然后在web.xml中配置，这样request和response的编码格式将统一

具体class 源码和 web.xml配置如下：

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.UnavailableException;

/**
 * Example filter that sets the character encoding to be used in parsing the
 * incoming request, either unconditionally or only if the client did not
 * specify a character encoding.  Configuration of this filter is based on
 * the following initialization parameters:
 *
 * encoding - The character encoding to be configured
 *     for this request, either conditionally or unconditionally based on
 *     the ignore initialization parameter.  This parameter
 *     is required, so there is no default.
 * ignore - If set to "true", any character encoding
 *     specified by the client is ignored, and the value returned by the
 *     selectEncoding() method is set.  If set to "false,
 *     selectEncoding() is called only if the
 *     client has not already specified an encoding.  By default, this
 *     parameter is set to "true".
 *
 *
 * Although this filter can be used unchanged, it is also easy to
 * subclass it and make the selectEncoding() method more
 * intelligent about what encoding to choose, based on characteristics of
 * the incoming request (such as the values of the Accept-Language
 * and User-Agent headers, or a value stashed in the current
 * user's session.
 *
 * @author Craig McClanahan
 * @version $Revision: 1.2 $ $Date: 2001/10/17 22:53:19 $
 */

public class SetCharacterEncodingFilter implements Filter {

    // ----------------------------------------------------- Instance Variables

    /**
     * The default character encoding to set for requests that pass through
     * this filter.
     */
    protected String encoding = null;

    /**
     * The filter configuration object we are associated with.  If this value
     * is null, this filter instance is not currently configured.
     */
    protected FilterConfig filterConfig = null;

    /**
     * Should a character encoding specified by the client be ignored?
     */
    protected boolean ignore = true;

    // --------------------------------------------------------- Public Methods

    /**
     * Take this filter out of service.
     */
    public void destroy() {

        this.encoding = null;
        this.filterConfig = null;

    }

    /**
     * Select and set (if specified) the character encoding to be used to
     * interpret request parameters for this request.
     *
     * @param request The servlet request we are processing
     * @param result The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
        throws IOException, ServletException {

        // Conditionally select and set the character encoding to be used
        if (ignore || (request.getCharacterEncoding() == null)) {
            String encoding = selectEncoding(request);
            if (encoding != null)
                request.setCharacterEncoding(encoding);
        }

        // Pass control on to the next filter
        chain.doFilter(request, response);

    }

    /**
     * Place this filter into service.
     *
     * @param filterConfig The filter configuration object
     */
    public void init(FilterConfig filterConfig) throws ServletException {

        this.filterConfig = filterConfig;
        this.encoding = filterConfig.getInitParameter("encoding");
        String value = filterConfig.getInitParameter("ignore");
        if (value == null)
            this.ignore = true;
        else if (value.equalsIgnoreCase("true"))
            this.ignore = true;
        else if (value.equalsIgnoreCase("yes"))
            this.ignore = true;
        else
            this.ignore = false;

    }

    // ------------------------------------------------------ Protected Methods

    /**
     * Select an appropriate character encoding to be used, based on the
     * characteristics of the current request and/or filter initialization
     * parameters.  If no character encoding should be set, return
     * null.
     *
     * The default implementation unconditionally returns the value configured
     * by the encoding initialization parameter for this
     * filter.
     *
     * @param request The servlet request we are processing
     */
    protected String selectEncoding(ServletRequest request) {

        return (this.encoding);

    }

}

配置 web.xml

 <!--中文编码Filter-->  
      <filter>   
         <filter-name>SetCharacterEncodingFilter</filter-name>   
          <filter-class>SetCharacterEncodingFilter</filter-class>   
                <init-param>  
                          <param-name>encoding</param-name>  
                          <param-value>UTF-8</param-value>  
                  </init-param>  
        </filter> 
         <filter-mapping>  
      <filter-name>SetCharacterEncodingFilter</filter-name>  
      <url-pattern>/*</url-pattern>  
      </filter-mapping>