java拦截器返回自定义数据

要在 Java 拦截器中返回自定义数据，可以通过在拦截器中使用 HttpServletResponse 对象来设置响应内容。以下是一个示例：

public class CustomInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // do something before the request is handled
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        // do something after the request is handled
        response.setContentType("application/json");
        response.setCharacterEncoding("UTF-8");
        PrintWriter out = response.getWriter();
        out.print("{\"message\": \"Custom response data\"}");
        out.flush();
        out.close();
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        // do something after the response is sent back to the client
    }
}

在上面的示例中，我们在 postHandle() 方法中设置了响应头的内容类型和编码，并使用 PrintWriter 对象将自定义数据输出到响应中。在此之后，拦截器将继续执行其它操作。