如何处理Spring MVC中呈现视图时引发的异常？

Question

那么，是否有一些Spring机制，我可以在其中注册一个捕获视图错误的异常处理程序？

Answer 1

先说一句：如果您只需要一个“静态”错误页面，而不需要太多的逻辑和模型准备，那么在web.xml中添加一个 -标记就足够了（参见下面的示例）。

否则，可能会有更好的方法来做到这一点，但这对我们很有效：

我们在web.xml中使用servlet ，该servlet 捕获所有异常并调用自定义的ErrorHandler，与我们在Spring HandlerExceptionResolver中使用的相同。

<filter>
   <filter-name>errorHandlerFilter</filter-name>
   <filter-class>org.example.filter.ErrorHandlerFilter</filter-class>
</filter>
<filter-mapping>
  <filter-name>errorHandlerFilter</filter-name>
  <url-pattern>/*</url-pattern>
</filter-mapping>

该实现基本上如下所示：

public class ErrorHandlerFilter implements Filter {

  ErrorHandler errorHandler;

  @Override
  public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
    try {
      filterChain.doFilter(request, response);
    } catch (Exception ex) {
      // call ErrorHandler and dispatch to error jsp
      String errorMessage = errorHandler.handle(request, response, ex);
      request.setAttribute("errorMessage", errorMessage);
      request.getRequestDispatcher("/WEB-INF/jsp/error/dispatch-error.jsp").forward(request, response);
    }

  @Override
  public void init(FilterConfig filterConfig) throws ServletException {
    errorHandler = (ErrorHandler) WebApplicationContextUtils
      .getRequiredWebApplicationContext(filterConfig.getServletContext())
      .getBean("defaultErrorHandler");
  }

  // ...
}

我相信这对于FreeMarker模板应该是一样的。当然，如果错误视图抛出错误，您或多或少别无选择。

为了捕获类似404的错误并为此准备模型，我们使用映射到error调度程序的过滤器：

<filter>
   <filter-name>errorDispatcherFilter</filter-name>
   <filter-class>org.example.filter.ErrorDispatcherFilter</filter-class>
</filter>
<filter-mapping>
  <filter-name>errorDispatcherFilter</filter-name>
  <url-pattern>/*</url-pattern>
  <dispatcher>ERROR</dispatcher>
</filter-mapping>

<error-page>
  <error-code>404</error-code>
  <location>/WEB-INF/jsp/error/dispatch-error.jsp</location>
</error-page>
<error-page>
  <exception-type>java.lang.Exception</exception-type>
  <location>/WEB-INF/jsp/error/dispatch-error.jsp</location>
</error-page>

@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

  final HttpServletRequest request = (HttpServletRequest) servletRequest;

  // handle code(s)
  final int code = (Integer) request.getAttribute("javax.servlet.error.status_code");
  if (code == 404) {
    final String uri = (String) request.getAttribute("javax.servlet.error.request_uri");
    request.setAttribute("errorMessage", "The requested page '" + uri + "' could not be found.");
  }

  // notify chain
  filterChain.doFilter(servletRequest, servletResponse);
}