Light Consumer 4j

Light Consumer 4j is a module that helps consumers to integrate with light-4j APIs easily. It is built on top of Http2Client & java8 completable future for multiple downstream API invocations. It also has a lot of extra features like connection pooling, circuit breaker, etc. Like Http2Client in light-4j, it supports direct URL and service discovery (Consul) to call the APIs.

Usage

Add dependency in your project.

<dependency>
    <groupId>com.networknt</groupId>
    <artifactId>light-consumer-4j</artifactId>
    <version>1.5.26</version>
</dependency>

Here are the methods available in ClientBuilder.

Future send() // Send request.

String getServiceUrl() // Get the resolved serviceUrl

disableHttp2() // Disable Http2, by default it is enabled.

setClientRequest(ClientRequest reg) // set client request to httpClientRequest.

setRequestBody(String requestBody) // set requestBody to httpClientRequest.

setHeaderValue(HttpString headerName,..) // set headerName and headerValue to httpClientRequest.

setApiHost(String apiUrl) // set apiUrl into httpClientRequest to call api with direct url .

setConnectionCacheTTLms(long tTLms) // set connection cache time out.

setRequestTimeout(TimeoutDef timeout) // set request time out

setConnectionRequestTimeout(TimeoutDef t)// set connection request timeout

setAuthToken(String authToken) // Set the auth token in the request

getAuthToken() // get authToken

addCCToken() // add the access token in request header and also checks access token expiration.

setServiceDef(ServiceDef serviceDef) // set protocol,service id , environment and requestKey to call api via consul

setMaxReqCount(int maxReqCount) // enable connection cache by request number

Here are the code examples to call the api.

Call the api with direct URL:

Example 1:

Future<ClientResponse> clientRequest = new HttpClientBuilder()
                      
    //set direct url
   .setApiHost("https://localhost:8453")
   .setClientRequest(new ClientRequest().setPath("/v1/customers/1").setMethod(Methods.GET))
   .setLatch(new CountDownLatch(1))
   .disableHttp2()
   .addCCToken()
   .setConnectionRequestTimeout(new TimeoutDef(100, TimeUnit.SECONDS))
   .setRequestTimeout(new TimeoutDef(100, TimeUnit.SECONDS))
   .setRequestBody("")
   .setConnectionCacheTTLms(10000)
   .setMaxReqCount(5)
   .send();
ClientResponse clientResponse = clientRequest.get();

Example 2:

            public static final String CUSTOMERS_URL = "https://localhost:8453";
            private static final String CUSTOMERS_PATH = "/v1/customers/{id}";
            
            HttpClientBuilder clientBuilder = new HttpClientBuilder();
            
            ClientRequest clientRequest = new ClientRequest().setMethod(Methods.GET)
            .setPath(CUSTOMERS_PATH.replace("{id}", id));
            
            clientBuilder.setClientRequest(clientRequest);
            clientBuilder.setLatch(new CountDownLatch(1));
            if (!Server.getServerConfig().isEnableHttp2()) {
              clientBuilder.disableHttp2();
            }
            clientBuilder.setApiHost(CUSTOMERS_URL);
            clientBuilder.setConnectionCacheTTLms(20000);
            clientBuilder.setMaxReqCount(5)
            clientBuilder.setConnectionRequestTimeout(new TimeoutDef(10, TimeUnit.SECONDS));
            Future<ClientResponse> clientBuilderRequest = clientBuilder.send();
            ClientResponse clientResponse = clientBuilderRequest.get();

Call the api via service discover (Consul):

Example 1:

Future<ClientResponse> clientRequest = new HttpClientBuilder()
                     
    //set protocol,service id , environment  and requestKey 
   .setServiceDef(new ServiceDef("https", "training.customers-1.00.00","training", null))
   .setClientRequest(new ClientRequest().setPath("/v1/customers/1").setMethod(Methods.GET))
   .setLatch(new CountDownLatch(1))
   .disableHttp2()
   .addCCToken()
   .setConnectionRequestTimeout(new TimeoutDef(100, TimeUnit.SECONDS))
   .setRequestTimeout(new TimeoutDef(100, TimeUnit.SECONDS))
   .setRequestBody("")
   .setConnectionCacheTTLms(10000)
   .setMaxReqCount(5)
   .send();
ClientResponse clientResponse = clientRequest.get();

Example 2:

            public static final String CUSTOMERS_SERVICE = "training.customers-1.00.00";
            private static final String CUSTOMERS_PATH = "/v1/customers/{id}";
            
            HttpClientBuilder clientBuilder = new HttpClientBuilder();
            
            ClientRequest clientRequest = new ClientRequest().setMethod(Methods.GET)
            .setPath(CUSTOMERS_PATH.replace("{id}", id));
            
            clientBuilder.setClientRequest(clientRequest);
            clientBuilder.setLatch(new CountDownLatch(1));
            if (!Server.getServerConfig().isEnableHttp2()) {
                clientBuilder.disableHttp2();
            }
            clientBuilder.setServiceDef(new ServiceDef("https", CUSTOMERS_SERVICE, "training", null));
            clientBuilder.setConnectionCacheTTLms(20000);
            clientBuilder.setMaxReqCount(5);
            clientBuilder.setConnectionRequestTimeout(new TimeoutDef(10, TimeUnit.SECONDS));
            Future<ClientResponse> clientBuilderRequest = clientBuilder.send();
            ClientResponse clientResponse = clientBuilderRequest.get();