How to use

Filter

in

javax.servlet

  public void doFilter(ServletRequest request, ServletResponse response) throws IOException, ServletException {
    if(position==filters.length) {
      // reached to the end
      chain.doFilter(request,response);
    } else {
      // call next
      filters[position++].doFilter(request,response,this);
    }
  }
}.doFilter(request,response);

/**
 * Initialize all the filters, calling each one's init method in turn in the order supplied.
 * @see Filter#init(FilterConfig)
 */
@Override
public void init(FilterConfig config) throws ServletException {
  for (Filter filter : this.filters) {
    filter.init(config);
  }
}

@Override
public void destroy() {
  this.delegate.destroy();
}

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    throws IOException, ServletException {
  if (wrappedFilter == null) {
    throw new ServletException("No wrappedFilter configured");
  }
  if (this.enable) {
    this.wrappedFilter.doFilter(request, response, chain);
  } else {
    chain.doFilter(request, response);
  }
}

 throw new ServletException(
   "Filters must be bound as singletons. "
     + filterKey
filter.init(
  new FilterConfig() {
   @Override

protected void deployNewFilter(Filter newFilter) throws ServletException {
  Filter oldFilter = filter;
  if (newFilter == null) {
    throw new ServletException("Cannot deploy null filter");
  }
  newFilter.init(filterConfig);
  filter = newFilter;
  if (oldFilter != null) {
    oldFilter.destroy();
  }
}

  try {
    filter = filterConfig.getFilter();
    filter.doFilter(request, response, this);
  } catch (IOException e) {
    throw e;
    throw e;
  } catch (Throwable e) {
    throw new ServletException("Throwable", e);
    servlet.service(request, response);
  } else {
    RequestDispatcher rd = configImpl.getServletContext().getNamedDispatcher("default");
    if (rd == null) {
      throw new ServletException("No Servlet Found");
  throw e;
} catch (Throwable e) {
  throw new ServletException("Throwable", e);

public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
  if (!initialized) {
    throw new ServletException(getClass().getName() + ".init(FilterConfig) was not called");
  }
  reloadIfNecessary();
  filter.doFilter(servletRequest, servletResponse, filterChain);
}

/**
 * Pass the call on to the Filter/Servlet.
 */
@Override
public void doFilter(ServletRequest request, ServletResponse response) throws ServletException, IOException {
  if (this.filter != null) {
    this.filter.doFilter(request, response, this.nextFilterChain);
  }
  else {
    Assert.state(this.servlet != null, "Neither a Filter not a Servlet set");
    this.servlet.service(request, response);
  }
}

/**
 * Actually invoke the delegate Filter with the given request and response.
 * @param delegate the delegate Filter
 * @param request the current HTTP request
 * @param response the current HTTP response
 * @param filterChain the current FilterChain
 * @throws ServletException if thrown by the Filter
 * @throws IOException if thrown by the Filter
 */
protected void invokeDelegate(
    Filter delegate, ServletRequest request, ServletResponse response, FilterChain filterChain)
    throws ServletException, IOException {
  delegate.doFilter(request, response, filterChain);
}

@Test
public void testFilterBasic() throws ServletException, IOException {
  Filter filter = makeFilter();
  try {
    filter.init(makeFilterConfig());
    filter.doFilter(makeRequest(), makeResponse(), makeFilterChain());
  }
  finally {
    filter.destroy();
  }
}

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
    throws IOException, ServletException {
  if (proxy == null) {
    synchronized (lock) {
      if (proxy == null) {
        Ioc ioc = Mvcs.ctx().getDefaultIoc();
        Filter proxy = ioc.get(null, beanName);
        proxy.init(filterConfig);
        this.proxy = proxy;
      }
    }
  }
  proxy.doFilter(request, response, chain);
}

/**
 * Reset the proxies and filter for a change in {@link SecurityRealm}.
 */
public void reset(SecurityRealm securityRealm) throws ServletException {
  if (securityRealm != null) {
    SecurityRealm.SecurityComponents sc = securityRealm.getSecurityComponents();
    AUTHENTICATION_MANAGER.setDelegate(sc.manager);
    USER_DETAILS_SERVICE_PROXY.setDelegate(sc.userDetails);
    REMEMBER_ME_SERVICES_PROXY.setDelegate(sc.rememberMe);
    // make sure this.filter is always a valid filter.
    Filter oldf = this.filter;
    Filter newf = securityRealm.createFilter(this.filterConfig);
    newf.init(this.filterConfig);
    this.filter = newf;
    if(oldf!=null)
      oldf.destroy();
  } else {
    // no security related filter needed.
    AUTHENTICATION_MANAGER.setDelegate(null);
    USER_DETAILS_SERVICE_PROXY.setDelegate(null);
    REMEMBER_ME_SERVICES_PROXY.setDelegate(null);
    filter = null;
  }
}

/**
 * Initialize the {@link Filter}
 *
 * @throws javax.servlet.ServletException
 */
public void init() throws ServletException {
  for (FilterConfigImpl f : filters) {
    if (f != null) {
      f.getFilter().init(f);
    }
  }
  if (servlet != null) {
    servlet.init(configImpl);
  }
}

@Test
public void testInit() {
  Filter filter = makeFilter();
  try {
    filter.init(makeFilterConfig());
  }
  catch (ServletException e) {
    assertNotNull(e.getMessage());
  }
  finally {
    filter.destroy();
  }
}

servlet.destroy();
filter.destroy();

@Override
public void init(FilterConfig filterConfig) throws ServletException {
  if (wrappedFilter == null) {
    throw new ServletException("No wrappedFilter configured");
  }
  if (this.enable) {
    this.wrappedFilter.init(filterConfig);
  }
}

protected void deployNewFilter(Filter newFilter) throws ServletException {
  Filter oldFilter = filter;
  if (newFilter == null) {
    throw new ServletException("Cannot deploy null filter");
  }
  newFilter.init(filterConfig);
  filter = newFilter;
  if (oldFilter != null) {
    oldFilter.destroy();
  }
}

public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
  if (!initialized) {
    throw new ServletException(getClass().getName() + ".init(FilterConfig) was not called");
  }
  reloadIfNecessary();
  filter.doFilter(servletRequest, servletResponse, filterChain);
}

/**
 * Pass the call on to the Filter/Servlet.
 */
@Override
public void doFilter(ServletRequest request, ServletResponse response) throws ServletException, IOException {
  if (this.filter != null) {
    this.filter.doFilter(request, response, this.nextFilterChain);
  }
  else {
    Assert.state(this.servlet != null, "Neither a Filter not a Servlet set");
    this.servlet.service(request, response);
  }
}