字符编码拦截器

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.annotation.WebFilter;
import javax.servlet.annotation.WebInitParam;

@WebFilter(urlPatterns = "/*", 
    initParams = { @WebInitParam(name = "encoding", value = "UTF-8") })
public class EncodingFilter implements Filter {

　　//设置默认编码为UTF-8
    private String charset = "UTF-8";

    @Override
    public void destroy() {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {
        request.setCharacterEncoding(this.charset);
        response.setCharacterEncoding(this.charset);
        chain.doFilter(request, response);
    }

    @Override
    public void init(FilterConfig config) throws ServletException {
        if (config.getInitParameter("encoding") != null) {
            this.charset = config.getInitParameter("encoding");
        }

    }

}