为 Servlet 添加 UTF8 过滤器

Question

您好，我使用了 Initializer，效果很好。

public class Initializer implements WebApplicationInitializer {

    public void onStartup(ServletContext servletContext)
            throws ServletException {
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
        ctx.register(WebAppConfig.class);
        servletContext.addListener(new ContextLoaderListener(ctx));

        ctx.setServletContext(servletContext);


        Dynamic servlet = servletContext.addServlet("dispatcher", new DispatcherServlet(ctx));
        servlet.addMapping("/");
        servlet.setLoadOnStartup(1);

        FilterRegistration.Dynamic filterRegistration = servletContext.addFilter("encodingFilter",
                new CharacterEncodingFilter());
        filterRegistration.setInitParameter("encoding", "UTF-8");
        filterRegistration.setInitParameter("forceEncoding", "true");
        filterRegistration.addMappingForUrlPatterns(null,true,"/*");
    }

然后我换了另一个：

public class Initializer extends AbstractAnnotationConfigDispatcherServletInitializer {


    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }

    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class<?>[]{WebAppConfig.class};
    }

    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class<?>[]{WebAppConfig.class};
    }
}

但是我不能添加这个方法：

public void onStartup(ServletContext servletContext) {
        FilterRegistration.Dynamic filterRegistration = servletContext.addFilter("encodingFilter",
                new CharacterEncodingFilter());
        filterRegistration.setInitParameter("encoding", "UTF-8");
        filterRegistration.setInitParameter("forceEncoding", "true");
        filterRegistration.addMappingForUrlPatterns(null, true, "/*");
    }

因为申请失败了。 我究竟做错了什么？如何将此过滤器添加到新的初始化程序以强制其工作？ 谢谢。

Answer 1

@Override
    protected FilterRegistration.Dynamic registerServletFilter(ServletContext servletContext, Filter filter) {

        FilterRegistration.Dynamic filterRegistration =     servletContext.addFilter("encodingFilter",
                new CharacterEncodingFilter());
        filterRegistration.setInitParameter("encoding", "UTF-8");
        filterRegistration.setInitParameter("forceEncoding", "true");
        filterRegistration.addMappingForUrlPatterns(null, true, "/*");

        return super.registerServletFilter(servletContext, filter);
    }