I need to create a reverse proxy that takes incoming request and based on the content of the request body, route the request to specific URI.
This is for a routing micro service that acts like a reverse proxy and does routing based on some information from each request body. This means for each request I need to parse the request body and get the "username" field and then make a JDBC connection to fetch additional information from the database. Based on that information in database, it would finally redirect the request to the correct URI.
From what I have now, I have 2 blocking methods. The first one is the parsing for the request body, the other one is the JDBC connection to the database. I understand that I should not put any blocking calls inside the gateway filter. I just don't know what I should do in this case. I could have both operations running async but in the end I still need the information from database to do routing.
#Bean
public RouteLocator apiLocator(RouteLocatorBuilder builder, XmlMapper xmlMapper) {
return builder.routes()
.route(r -> r
.path("/test")
.and()
.readBody(String.class, s -> true) // Read the request body, data will be cached as cachedRequestBodyObject
.filters(f -> f.filter(new GatewayFilter() {
#Override
public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {
try {
// The following method is blocking and should not be put here
xmlMapper.readValue((String) exchange.getAttribute("cachedRequestBodyObject"), Map.class);
} catch (Exception e) {
//TODO
}
return chain.filter(exchange);
}
}))
.uri("http://localhost:8080"))
.build();
}
The above example only includes the blocking parsing as my request body is XML based. My IDE is warning me of having a blocking call there which I really appreciate.
Any help is greatly appreciated. Thank you everyone!
After some research, Mono.fromCallable seems to be a good fit. I then asked the same question directly under the github repo, it turns out that using a servlet app may be better. For anyone who is interested to see what I came up with, please take a look here https://github.com/spring-cloud/spring-cloud-gateway/issues/1229
Related
I am using Jersey Rest implementation. There are one Rest Services Called HelloWorld. See the below code.
Please consider this code as reference not as compiled code.
#Path("helloWorld")
public class HelloWorld{
#Path("test")
#Produces(...)
#Consum(...)
#GET
public Response test(Person person){
System.out.println(person);
}
}
I am using Jersey client to sent the request.
Here My question is apart from POST method is there any way to send the object to GET method directly. Instead of QueryString.
Please let me if there is any way to do so.
Thanks
So the problem shouldn't be with the server. I did a few tests on different servers (not weblogic as I don't use it) and all of them seem to have no problems accepting a body in the GET request. The problem seem to be with the client. To test I used the following code
ClientBuilder.newClient()
.target("http://localhost:8080/api/get-body")
.property(ClientProperties.SUPPRESS_HTTP_COMPLIANCE_VALIDATION, true)
.request()
.method(HttpMethod.GET, Entity.text("Hello World"));
The SUPPRESS_HTTP_COMPLIANCE_VALIDATION allows us to pass a body to the request. If we didn't use this, then we would get an error.
The problem with this code, is that even though we set this override property, the client completely overrides the GET method and automatically makes it a POST method, so I would get back a 405 Method Not Allowed.
The solution I came up with is to just allow the client to set a header, e.g. X-GET-BODY-OVERRIDE, and then use a #PreMatching filter on the server side to check for this header. If the header is present, then just change the method to a GET
#Provider
#PreMatching
public class GetWithBodyFilter implements ContainerRequestFilter {
#Override
public void filter(ContainerRequestContext request) throws IOException {
String getOverride = request.getHeaderString("X-GET-BODY-OVERRIDE");
if (getOverride != null && "true".equalsIgnoreCase(getOverride)) {
request.setMethod(HttpMethod.GET);
}
}
}
Then just register the filter with the server side. On the client, you would simply need to add the header
ClientBuilder.newClient()
.target("http://localhost:8080/api/get-body")
.property(ClientProperties.SUPPRESS_HTTP_COMPLIANCE_VALIDATION, true)
.request()
.header("X-GET-BODY-OVERRIDE", "True")
.method(HttpMethod.GET, Entity.text("Hello World"));
This solution is good because it takes into account more than just the Jersey client, in regards with being able to send a body in the GET request.
I'm new to Vert.x and trying I am trying to implement a small REST API that stores its data in JSON files on the local file system.
So far I managed to implement the REST API since Vertx is very well documented on that part.
What I'm currently looking for are examples how to build data access objects in Vert.x. How can I implement a Verticle that can perform crud operations on a text file containing JSON?
Can you provide me any examples? Any hints?
UPDATE 1:
By CRUD operations on a file I'm thinking of the following. Imagine there is a REST resource called Records exposed on the the path /api/v1/user/:userid/records/.
In my verticle that starts my HTTP server I have the following routes.
router.get('/api/user/:userid/records').handler(this.&handleGetRecords)
router.post('/api/user/:userid/records').handler(this.&handleNewRecord)
The handler methods handleGetRecords and handleNewRecord are sending a message using the Vertx event bus.
request.bodyHandler({ b ->
def userid = request.getParam('userid')
logger.info "Reading record for user {}", userid
vertx.eventBus().send(GET_TIME_ENTRIES.name(), "read time records", [headers: [userId: userid]], { reply ->
// This handler will be called for every request
def response = routingContext.response()
if (reply.succeeded()) {
response.putHeader("content-type", "text/json")
// Write to the response and end it
response.end(reply.result().body())
} else {
logger.warn("Reply failed {}", reply.failed())
response.statusCode = 500
response.putHeader("content-type", "text/plain")
response.end('That did not work out well')
}
})
})
Then there is another verticle that consumes these messages GET_TIME_ENTRIES or CREATE_TIME_ENTRY. I think of this consumer verticle as a Data Access Object for Records. This verticle can read a file of the given :userid that contains all user records. The verticle is able to
add a record
read all records
read a specific record
update a record
delete a or all records
Here is the example of reading all records.
vertx.eventBus().consumer(GET_TIME_ENTRIES.name(), { message ->
String userId = message.headers().get('userId')
String absPath = "${this.source}/${userId}.json" as String
vertx.fileSystem().readFile(absPath, { result ->
if (result.succeeded()) {
logger.info("About to read from user file {}", absPath)
def jsonObject = new JsonObject(result.result().toString())
message.reply(jsonObject.getJsonArray('records').toString())
} else {
logger.warn("User file {} does not exist", absPath)
message.fail(404, "user ${userId} does not exist")
}
})
})
What I trying to achieve is to read the file like I did above and deserialise the JSON into a POJO (e.g. a List<Records>). This seems much more convenient that working with JsonObject of Vertx. I don't want to manipulate the JsonObject instance.
First of all, your approach using EventBus is fine, in my opinion. It may be a bit slower, because EventBus will serialize/deserialize your objects, but it gives you a very good decoupling.
Example of another approach you can see here:
https://github.com/aesteve/vertx-feeds/blob/master/src/main/java/io/vertx/examples/feeds/dao/RedisDAO.java
Note how every method receives handler as its last argument:
public void getMaxDate(String feedHash, Handler<Date> handler) {
More coupled, but also more efficient.
And for a more classic and straightforward approach, you can see the official examples:
https://github.com/aokolnychyi/vertx-example/blob/master/src/main/java/com/aokolnychyi/vertx/example/dao/MongoDbTodoDaoImpl.java
You can see that here DAO is pretty much synchronous, but since the handlers are still async, it's fine anyway.
I guess the following link will help you out and this is a good example of Vertx crud operations.
Vertx student crud operations using hikari
I have a ServletFilter (which happens to be a GuiceShiroFilter) that processes incoming web requests before they go to a Jersey 1.x Resource.
However, in some situations (namely when Shiro finds that the request is not authenticated), I want to change which Jersey resource answers my request, without the resource that otherwise would have answered even being able to respond.
Here's what I have (in my Shiro AuthenticatingFilter.onLoginFailure()):
ServletRequest request = ...;
RequestDispatcher disp = request.getRequestDispatcher("/resource/that/always/responsds/with/a/403");
try {
disp.forward(request, response);
} catch (ServletException | IOException e) {
e.printStackTrace();
}
// this is needed to prevent the woud-be resource from responding as well
return false;
The problem of this server-side redirect is that not returning false will invoke both my resource for "/resource/that/always/responsds/with/a/403" and the original would-be response, and in the best case the response body contains both responses concatenated.
Is there a way to modify an existing instance of (Http)ServletRequest from a Filter such that later on, only the redirected-to resource can answer?
I dug into the issue a little bit and I realized that there is little I can do here, given that I don't control how the filter chain is processed further.
In a generic Filter, the implementer can wrap the current ServletRequest (in doFilter() in a HttpServletRequestWrapper implementation. This wrapper can then override the request URI. However, this requires that the implementer has control over how the filter chain is continued (which is where the wrapped request can be fed back into the execution path), but this is not the case in my situation, where Shiro controls that.
With Shiro, the filter chain continuation is controlled in AdviceFilter.doFilterInternal(), many layers above my own AuthenticatingFilter implementation.
So for now, my best bet is to do what I already described above: Invoke another resource - free from filters - by using a RequestDispatcher and stop the filter chain by returning false at the end of my AuthenticatingFilter's onLoginFailure()
I am writing some interface for users to collect data and send to a server. I went for GWT for various reasons.
Now, when I try to call my server:
String url = "http://127.0.0.1:3000/data/collection.xml";
RequestBuilder builder = new RequestBuilder(RequestBuilder.POST, URL.encode(url));
Request request = builder.sendRequest(data, new RequestCallback() {
public void onResponseReceived(Request request, Response response) {
if (200 == response.getStatusCode()) {
result.setText("SUCCESS!");
} else {
result.setText("ERROR with code: " + response.getStatusCode());
My server gets the request (a POST with some data) but I get ERROR with code: 0 (!) all the time. I guess this has to do with SOP. I read lots about this SOP but I am even more confused now. I tried to follow this tutorial but that's using a different approach (I managed to adapt it to issue GET calls only, but return objects are always null).
Can anyone point me into the right direction? thanks
You can not call any service from another server because of SOP. What you can do, you can use your original server as proxy to other servers.. I would recommend you to read this tutorial.
I have to consume a service provided by one of our partners. I was given little direction, but was told the security was to be PasswordDigest. I looked it up and immediatly saw lots of references to WSE, so off I went. It was very easy to implement and in no time I had a standard WSE user token using PasswordDigest sitting in the SOAP headers of my messages.
When we started testing today I was immediatly told (by the error message) that things weren't right. Turns out, out partner doesn't look in the SOAP header, but rather wants the security info in the http header.
I have seen lots of articles on how to add custom http headers to a proxy class, but my proxy inherits from SoapHttpClientProtocol which doesn't have a headers collection to add to. I was looking at making a raw httpWebRequest, but I have a specific method to access that has some complex parameters to deal with (and besides it feels like going backwords).
What is the best way to add custom http headers to a service proxy class that doesn't have a GetWebRequest method?
For reference:
Proxy class decleration:
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.Web.Services", "2.0.50727.3053")]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
[System.Web.Services.WebServiceBindingAttribute(Name="MtomServiceSoap11", namespace="http://ws.xxxxxxx.com/")]
public partial class MtomServiceService : System.Web.Services.Protocols.SoapHttpClientProtocol {
Target method I need to call:
[System.Web.Services.Protocols.SoapDocumentMethodAttribute("", Use=System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Bare)]
[return: System.Xml.Serialization.XmlElementAttribute("uploadDocumentResponse", Namespace="http://ws.edsmtom.citizensfla.com/")]
public uploadDocumentResponse uploadDocument([System.Xml.Serialization.XmlElementAttribute(Namespace="http://ws.xxxxxxx.com/")] uploadDocumentRequest uploadDocumentRequest) {
object[] results = this.Invoke("uploadDocument", new object[] {
uploadDocumentRequest});
return ((uploadDocumentResponse)(results[0]));
}
}
The actual call to the Service is simple. The objects being pass in are not:
request.criteria = docCriteria;
request.document = document;
var result = service.uploadDocument(request);
Thanks.
It figures that 30 minutes after posting I would stumble across the answer. While the proxy class decelaration does not create a GetWebRequest method, its base class System.Web.Services.Protocols.SoapHttpClientProtocol has it and it can be overridden.
protected override System.Net.WebRequest GetWebRequest(Uri uri)
{
var request = base.GetWebRequest(uri);
request.Headers.Add("blah", "blah"); // <----
return request;
}