过滤器实现编码过滤处理

/**
 * 过滤器实现编码过滤
 * @author 王东海
 * @2017年4月17日
 */
//定义拦截的资源，这里拦截的/*的所有
@WebFilter(filterName="EncodeFilter",urlPatterns="/*")
public class EncodeFilter implements Filter {

    @Override
    public void destroy() {

    }

    @Override
    public void doFilter(ServletRequest arg0, ServletResponse arg1,
            FilterChain chain) throws IOException, ServletException {
        //在doFilter里面实现相应的拦截过滤 
        /**
         * 1、拦截目标，所有资源
         * 2、get    post做相应的编码处理
         * 3、放行我们的资源
         */
        
        //1、先转换
        HttpServletRequest request = (HttpServletRequest) arg0;
        HttpServletResponse response = (HttpServletResponse) arg1;
        //2、拿到它的请求类型
        String method = request.getMethod();
        response.setCharacterEncoding("utf-8");
        
        /**
         * 做相应的判断
         * 如果说拿到是get请求，需要对我们的request 进行包装,
         * 包装需要继承一个HttpServletRequestWrapper类
         */
        if ("GET".equals(method)) {
            
            EncodeRequest encodeRequest = new EncodeRequest(request);
            chain.doFilter(encodeRequest, response);
        }else {
            request.setCharacterEncoding("utf-8");
            chain.doFilter(request, response);
        }
        
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {

    }

}

public class EncodeRequest extends HttpServletRequestWrapper {

    private HttpServletRequest request;
    
    public EncodeRequest(HttpServletRequest request) {
        super(request);
        //构造器里进行参数的接受
        this.request = request;
    }

    //需要重写getParameter方法
    @Override
    public String getParameter(String name) {

        String param = request.getParameter(name);
        /**
         * ISO8859-1 转换为 utf-8
         */
        //不为空的时候对它进行一个转换
        if (!MyStringUtil.isNullOrEmpty(param)) {
            
            try {
                //先变为字节数据传入编码ISO8859-1转变为：utf-8
                param = new String(param.getBytes("ISO8859-1"),"utf-8");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
        }
        
        return param;
    }

}