URL path matcher in java (Spring) - java

in our application we are creating request filters which should not be hit for some urls. We want be able to exclude urls like spring do witch url patterns, e.g.:
// register filter in bean
FilterRegistrationBean filterBeanRegistration = new FilterRegistrationBean();
filterBeanRegistration.setFilter(myFilter());
filterBeanRegistration.addInitParameter("excluded", "*/foo/**, */bar/**");
...
and new filter doesn't hit urls like domain:8080/aaa/foo/xxxx, domain:8080/bbb/bar/xxxx .
Can you tell me how to do that with spring classes or another simple way? Thank you in advice.
EDIT:
There is FilterBeanRegistration#addUrlPatterns(String... urls) method where I can specify urls, but there is no any format which tells which url should hit. For our purposes is better exclude some urls.

You can use org.springframework.web.filter.OncePerRequestFilter. It gets executed once every incoming request. You can override shouldNotFilter method to exclude the URLs you don't want the filter to run for. Example code:
public class MyFilter extends OncePerRequestFilter {
private static final String[] excludedEndpoints = new String[] {"*/foo/**, */bar/**"};
#Override
protected boolean shouldNotFilter(HttpServletRequest request) throws ServletException {
return Arrays.stream(excludedEndpoints)
.anyMatch(e -> new AntPathMatcher().match(e, request.getServletPath()));
}
#Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
FilterChain filterChain) throws ServletException, IOException {
// Filtering logic goes here. call below line on successful authentication.
filterChain.doFilter(request, response);
}
}

Related

How to print ServletOutputStream as string? [duplicate]

I am trying to log (just to console write now for simplicity sake) the final rendered HTML that will be returned by the HttpServletResponse. (i.e. the body) To this end, I am using the HandlerInterceptorAdapter from Spring MVC like so:
public class VxmlResponseInterceptor extends HandlerInterceptorAdapter {
#Override
public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
System.out.println(response.toString());
}
}
This works as expected and I see the HTTP response headers in the console. My question is if there is a relatively simple way to log the entire response body (i.e. final rendered HTML) to the console without having to resort to doing jumping jacks with PrintWriters, OutputStream's and the like.
Thanks in advance.
This would be better done using a Servlet Filter rather than a Spring HandlerInterceptor, for the reason that a Filter is allowed to substitute the request and/or response objects, and you could use this mechanism to substitute the response with a wrapper which logs the response output.
This would involve writing a subclass of HttpServletResponseWrapper, overriding getOutputStream (and possibly also getWriter()). These methods would return OutputStream/PrintWriter implementations that siphon off the response stream into a log, in addition to sending to its original destination. An easy way to do this is using TeeOutputStream from Apache Commons IO, but it's not hard to implement yourself.
Here's an example of the sort of thing you could do, making use of Spring's GenericFilterBean and DelegatingServletResponseStream, as well as TeeOutputStream, to make things easier:
public class ResponseLoggingFilter extends GenericFilterBean {
#Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException, ServletException {
HttpServletResponse responseWrapper = loggingResponseWrapper((HttpServletResponse) response);
filterChain.doFilter(request, responseWrapper);
}
private HttpServletResponse loggingResponseWrapper(HttpServletResponse response) {
return new HttpServletResponseWrapper(response) {
#Override
public ServletOutputStream getOutputStream() throws IOException {
return new DelegatingServletOutputStream(
new TeeOutputStream(super.getOutputStream(), loggingOutputStream())
);
}
};
}
private OutputStream loggingOutputStream() {
return System.out;
}
}
This logs everything to STDOUT. If you want to log to a file, it'll get a big more complex, what with making sure the streams get closed and so on, but the principle remains the same.
If you're using (or considering) logback as your logging framework, there is a nice servlet filter already available that does exactly that. Checkout the TeeFilter chapter in the documentation.
I've been looking for a way to log full HTTP Request/Response for a while and discovered it has been solved for me in the Tomcat 7 RequestDumperFilter. It works as advertised from a Tomcat 7 container. If you want to use it in Jetty, the class works fine stand-alone or, as I did, copied and adapted to the specific needs of my environment.
I made a small library spring-mvc-logger available via maven central.
Add to pom.xml:
<dependency>
<groupId>com.github.isrsal</groupId>
<artifactId>spring-mvc-logger</artifactId>
<version>0.2</version>
</dependency>
Add to web.xml:
<filter>
<filter-name>loggingFilter</filter-name>
<filter-class>com.github.isrsal.logging.LoggingFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>loggingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
Add to log4j.xml:
<logger name="com.github.isrsal.logging.LoggingFilter">
<level value="DEBUG"/>
</logger>
the code pasted below works with my tests and can be downloaded from my github project, sharing after applying a solution based on that on a production project
#Configuration
public class LoggingFilter extends GenericFilterBean {
/**
* It's important that you actually register your filter this way rather then just annotating it
* as #Component as you need to be able to set for which "DispatcherType"s to enable the filter
* (see point *1*)
*
* #return
*/
#Bean
public FilterRegistrationBean<LoggingFilter> initFilter() {
FilterRegistrationBean<LoggingFilter> registrationBean = new FilterRegistrationBean<>();
registrationBean.setFilter(new LoggingFilter());
// *1* make sure you sett all dispatcher types if you want the filter to log upon
registrationBean.setDispatcherTypes(EnumSet.allOf(DispatcherType.class));
// *2* this should put your filter above any other filter
registrationBean.setOrder(Ordered.HIGHEST_PRECEDENCE);
return registrationBean;
}
#Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
ContentCachingRequestWrapper wreq =
new ContentCachingRequestWrapper(
(HttpServletRequest) request);
ContentCachingResponseWrapper wres =
new ContentCachingResponseWrapper(
(HttpServletResponse) response);
try {
// let it be ...
chain.doFilter(wreq, wres);
// makes sure that the input is read (e.g. in 404 it may not be)
while (wreq.getInputStream().read() >= 0);
System.out.printf("=== REQUEST%n%s%n=== end request%n",
new String(wreq.getContentAsByteArray()));
// Do whatever logging you wish here, in this case I'm writing request
// and response to system out which is probably not what you wish to do
System.out.printf("=== RESPONSE%n%s%n=== end response%n",
new String(wres.getContentAsByteArray()));
// this is specific of the "ContentCachingResponseWrapper" we are relying on,
// make sure you call it after you read the content from the response
wres.copyBodyToResponse();
// One more point, in case of redirect this will be called twice! beware to handle that
// somewhat
} catch (Throwable t) {
// Do whatever logging you whish here, too
// here you should also be logging the error!!!
throw t;
}
}
}

any way to route all the requests to a method before they are redirected to the correct ones in servlet?

I'm trying to see if there's a way to pre-check all the requests before they are routed to the correct method?
all of my requests would have version# in param. it would be really helpful to check that at first place and decide whether the client needs to upgrade or not. it is a bit painful to check in all the methods, so I was wondering if there's a way to 'filter' the request at first. Thanks!
What you want is called a Filter.
See The Essentials of Filters
Example
#WebFilter( urlPatterns = "/*" ) // Filter all URLs
public class VersionFilter implements Filter {
#Override
public void doFilter( ServletRequest request, ServletResponse response, FilterChain chain ) throws IOException, ServletException {
// TODO Do your filtering here
}
#Override
public void init( FilterConfig filterConfig ) throws ServletException { ... }
#Override
public void destroy() { ... }
}

Spring #RequestMapping

I have a question with Spring MVC RequestMapping annotation. need your help.
I have created one IPSLcontroller and i want that IPSLcontroller to handle all request url.i have created two method in this controller.
1)handleLogoutRequest :- this method should invoke on below url.
2)handleRequest :- this method should invoke on all request url otherthan logout.
http://localhost:9086/webapp/login
or
http://localhost:9086/webapp/add
or
http://localhost:9086/webapp/remove
here is my sample code. but it's not working as expected.
#Controller
public class IPSLController {
#RequestMapping(value={"/logout/*"},method = RequestMethod.POST)
protected void handleLogoutRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out
.println("........................IPSLController logout request.......................................");
}
#RequestMapping(method = RequestMethod.POST,value={"/*"})
protected void handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out
.println("........................IPSLController all request Post.......................................");
}
}
You should use a general Prefix for every controller you use, so you can differ between them better. Also you donĀ“t need any "/" for calls like this.
#Controller
#RequestMapping("ispl")
public class IPSLController {
#RequestMapping(value={"logout"},method = RequestMethod.POST)
protected void handleLogoutRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out
.println("........................IPSLController logout request.......................................");
}
#RequestMapping(method = RequestMethod.POST,value={"hello"})
protected void handleRequest(HttpServletRequest request,
HttpServletResponse response) throws Exception {
System.out
.println("........................IPSLController all request Post.......................................");
}
}
If you now want to call them over a ServletRequest or with a restService or something similar you should declare them like this
#GET
#Path("ispl/logout")
public void Method (HttpServletResponse ...)
Well it is working the way it should. You have a mapping for /* and for /logout/*. So when you post to /logout it invokes the method for /*. I suspect that if you post to /logout/something it would invoke your logout handler.
If you want it to work, you cannot have a wildcard mapping for the second method. At least use /something/* so that spring can make a correct decision on mappings.

How do I exclude a specific URL in a filter in Spring?

I have a basic application filter config that looks like this:
#Configuration
public class ApplicationFilterConfig {
/**
* Check if user is logged in
*/
#Bean
public FilterRegistrationBean applicationFilterRegistration() {
// created a collections that need logins to be validated.
ArrayList<String> urlPatterns = new ArrayList<String>();
urlPatterns.add("/home");
urlPatterns.add("/about");
urlPatterns.add("/contact");
// ...
LoginFilter loginFilter = new LoginFilter();
FilterRegistrationBean registration = new FilterRegistrationBean();
registration.setFilter(loginFilter);
registration.setUrlPatterns(urlPatterns);
registration.setOrder(1);
return registration;
}
}
However, the list urlPatterns grows to be very long, even when using the star annotation (e.g. /employees/*). The main reason why I don't just use /* is because I don't want to require login validation for my login page. If I did, it'd create an infinite loop of redirects.
Does the FilterRegistrationBean class allow you to apply a filter to all URL patterns except certain patterns?
I could put everything except the login page in a directory and set my URL pattern to be /subdirectory/* but that adds an unnecessary level of depth to every file in my webapp.
FilterRegistrationBean doesnot provide(atleast until now) any method to exclude URL patterns. But it can be taken care from from Filter implementation(in this case its LoginFilter). Implement LoginFilter by extending OncePerRequestFilter which has a method called shouldNotFilter() which can be overriden to suit your needs.
public class LoginFilter extends OncePerRequestFilter {
private List<String> excludeUrlPatterns = new ArrayList<String();
#Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
FilterChain filterChain) throws ServletException, IOException
{
// Implementation....
}
#Override
protected boolean shouldNotFilter(HttpServletRequest request) throws ServletException
{
// Populate excludeUrlPatterns on which one to exclude here
}
}
For more details you can follow this link

Static or nonstatic action in mvc?

i want to ask you about mvc. How it works. So, this is simple example(I don't use any frameworks)
in Controller(Servlet):
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
processRequest(request, response);
}
private void processRequest(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
String page = null;
AbstractCommand action;
action = ActionFactory.getAction(request);// get command from factory
page = action.execute(request, response);
RequestDispatcher dispatcher = getServletContext()
.getRequestDispatcher(page);
dispatcher.forward(request, response);
}
for action we create a common interface(Strategy pattern):
public interface AbstractAction {
public String execute(HttpServletRequest request, HttpServletResponse response);
}
Simple Action(Example):
public class HelloAction implements AbstractAction {
#Override
public String execute(HttpServletRequest request,
HttpServletResponse response) {
//....(some actions to modify request)
String page = "/main.jsp";
return page;
}
}
And now, our factory:
public class ActionFactory {
private enum Actions{
HELLO;
}
public static AbstractAction getAction(HttpServletRequest request){
String action = request.getParameter("action");//take parameter from jsp
Actions actionEnum = Actions.valueOf(action.toUpperCase());
switch (actionEnum) {
case HELLO:
return new HelloAction();
}
}
}
We came to the place where I am in confused. Servlet is initialized only once, and only one for all requests. Just forwards requests to the actions where we modify request or response. But, we create NEW instance of the class for every request. Here can occur memory overflow!? Or not?
Can we make these actions static(static method, one for all request)? If two requests come at the same time what will happen to them?
What do you think about this, please share your experience.
P.S. sorry for bad english.
How about Singleton pattern to get the instance of the Action class ?
Just add some abstact getInstance() method in AbstractAction.
Make every implementation provide its own instance.
In every implementation class, use Singleton pattern so that only one instance exists.
Make sure no action class stores any data related to a specific request.
As i understood the jsp, the whole thing is stateless, if u access the servlet by http request, the servlet will be created in a new instance.
After leaving the servlet by .forward(), it will be released by garbage collection.
2,3,...,n requests = 2,3,...,n servlets.
by forwarding to a jsp, the only way to access the servlet from jsp is a new http request = new servlet. ( will move to the doPost method)

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