package filters;
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);

    }

}

    Set Character Encoding
    filters.SetCharacterEncodingFilter
    
      encoding
      UTF-8
    
  
  
    Set Character Encoding
    /*
  

#Application Resource for the logon.jsp
logon.jsp.title=登录页
logon.jsp.page.heading=欢迎 世界!
logon.jsp.prompt.username=用户名:
logon.jsp.prompt.password=口令:
logon.jsp.prompt.submit=提交
logon.jsp.prompt.reset=复位

#Application Resource for the main.jsp
main.jsp.title=主页
main.jsp.welcome=欢迎:

#Application Resource for the LogonAction.java
error.missing.username=
没有输入用户名

error.missing.password=
没有输入口令


#Application Resource for the UserInfoBo.java
error.noMatch=
没有匹配的用户


#Application Resource for the UserInfoBo.java
error.logon.invalid=
用户名/口令是无效的

error.removed.user=
找不到该用户

error.unexpected=
不可预期的错误

#Application Resource for the logon.jsp
logon.jsp.title=u767bu5f55u9875
logon.jsp.page.heading=u6b22u8fce u4e16u754c!
logon.jsp.prompt.username=u7528u6237u540d:
logon.jsp.prompt.password=u53e3u4ee4:
logon.jsp.prompt.submit=u63d0u4ea4
logon.jsp.prompt.reset=u590du4f4d

#Application Resource for the main.jsp
main.jsp.title=u4e3bu9875
main.jsp.welcome=u6b22u8fce:

#Application Resource for the LogonAction.java
error.missing.username=
u6ca1u6709u8f93u5165u7528u6237u540d

error.missing.password=
u6ca1u6709u8f93u5165u53e3u4ee4


#Application Resource for the UserInfoBo.java
error.noMatch=
u6ca1u6709u5339u914du7684u7528u6237


#Application Resource for the UserInfoBo.java
error.logon.invalid=
u7528u6237u540d/u53e3u4ee4u662fu65e0u6548u7684

error.removed.user=
u627eu4e0du5230u8be5u7528u6237

error.unexpected=
u4e0du53efu9884u671fu7684u9519u8bef