check jwt token expiration and refresh token if necessary

README.md

@@ -100,7 +100,7 @@ You can import it to your maven or gradle project as a dependency
 <dependency>
 	<groupId>io.camunda</groupId>
 	<artifactId>camunda-operate-client-java</artifactId>
-	<version>1.1.0</version>
+	<version>1.2.0</version>
 </dependency>
 ```
 

build.gradle

@@ -6,7 +6,7 @@ plugins {
 }
 
 group = 'io.camunda'
-version = '1.1.0'
+version = '1.2.0'
 sourceCompatibility = '8'
 
 repositories {

src/main/java/io/camunda/operate/CamundaOperateClient.java

@@ -37,9 +37,13 @@
 
 public class CamundaOperateClient {
 
+    private AuthInterface authentication;
+
     private String operateUrl;
 
     private Header authHeader;
+
+    private int tokenExpiration;
 
     public ProcessDefinition getProcessDefinition(Long key) throws OperateException {
         return get(key, ProcessDefinition.class);
@@ -161,6 +165,7 @@ private <T> T get(Long key, Class<T> resultType) throws OperateException {
     }
 
     protected String executeQuery(ClassicHttpRequest httpRequest) throws OperateException {
+        reconnectEventually();
         try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
             try (CloseableHttpResponse response = httpClient.execute(httpRequest)) {
                 return new String(Java8Utils.readAllBytes(response.getEntity().getContent()), StandardCharsets.UTF_8);
@@ -186,6 +191,16 @@ public void setAuthHeader(Header authHeader) {
         this.authHeader = authHeader;
     }
 
+    public void setTokenExpiration(int tokenExpiration) {
+        this.tokenExpiration = tokenExpiration;
+    }
+
+    private void reconnectEventually() throws OperateException {
+        if (this.tokenExpiration>0 && this.tokenExpiration<(System.currentTimeMillis()/1000-30)) {
+            authentication.authenticate(this);
+        }
+    }
+
     public static class Builder {
 
         private AuthInterface authentication;
@@ -220,6 +235,7 @@ public CamundaOperateClient build() throws OperateException {
             } else {
                 client = new CamundaOperateClient();
             }
+            client.authentication = authentication;
             client.operateUrl = operateUrl;
             authentication.authenticate(client);
             return client;

src/main/java/io/camunda/operate/auth/JwtAuthentication.java

@@ -0,0 +1,41 @@
+package io.camunda.operate.auth;
+
+import java.util.Base64;
+
+import org.apache.hc.core5.http.message.BasicHeader;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import io.camunda.operate.CamundaOperateClient;
+import io.camunda.operate.exception.OperateException;
+
+public abstract class JwtAuthentication implements AuthInterface {
+
+    private static final ObjectMapper MAPPER = new ObjectMapper();
+    private static final Base64.Decoder DECODER = Base64.getUrlDecoder();
+
+    public int getExpiration(String token) throws OperateException {
+        try {
+            String[] chunks = token.split("\\.");
+
+
+        String payload = new String(DECODER.decode(chunks[1]));
+        JsonNode jsonPayload = MAPPER.readValue(payload, JsonNode.class);
+        JsonNode exp = jsonPayload.get("exp");
+        if (exp==null) {
+            return 0;
+        } else {
+            return exp.asInt();
+        }
+        } catch (JsonProcessingException e) {
+            throw new OperateException("Token is not readable", e);
+        }
+    }
+
+    public void setToken(CamundaOperateClient client, String token) throws OperateException {
+        client.setAuthHeader(new BasicHeader("Authorization", "Bearer " + token));
+        client.setTokenExpiration(getExpiration(token));
+    }
+}

src/main/java/io/camunda/operate/auth/LocalIdentityAuthentication.java

@@ -9,15 +9,13 @@
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 
-import org.apache.hc.core5.http.message.BasicHeader;
-
 import com.fasterxml.jackson.databind.JsonNode;
 
 import io.camunda.operate.CamundaOperateClient;
 import io.camunda.operate.exception.OperateException;
 import io.camunda.operate.util.JsonUtils;
 
-public class LocalIdentityAuthentication implements AuthInterface {
+public class LocalIdentityAuthentication extends JwtAuthentication {
 
     private String clientId;
     private String clientSecret;
@@ -83,7 +81,7 @@ public void authenticate(CamundaOperateClient client) throws OperateException {
                     }
                     JsonNode responseBody = JsonUtils.toJsonNode(response.toString());
                     String token = responseBody.get("access_token").asText();
-                    client.setAuthHeader(new BasicHeader("Authorization", "Bearer " + token));
+                    setToken(client, token);
                 }
             } else {
                 throw new OperateException("Error "+conn.getResponseCode()+" obtaining access token : "+conn.getResponseMessage());

src/main/java/io/camunda/operate/auth/SaasAuthentication.java

@@ -7,15 +7,14 @@
 import org.apache.hc.client5.http.impl.classic.CloseableHttpResponse;
 import org.apache.hc.client5.http.impl.classic.HttpClients;
 import org.apache.hc.core5.http.io.entity.StringEntity;
-import org.apache.hc.core5.http.message.BasicHeader;
 
 import com.fasterxml.jackson.databind.JsonNode;
 
 import io.camunda.operate.CamundaOperateClient;
 import io.camunda.operate.exception.OperateException;
 import io.camunda.operate.util.JsonUtils;
 
-public class SaasAuthentication implements AuthInterface {
+public class SaasAuthentication extends JwtAuthentication {
 
     private String clientId;
     private String clientSecret;
@@ -40,7 +39,7 @@ public void authenticate(CamundaOperateClient client) throws OperateException {
                 JsonNode responseBody = JsonUtils.toJsonNode(response.getEntity().getContent());
                 String token = responseBody.get("access_token").asText();
 
-                client.setAuthHeader(new BasicHeader("Authorization", "Bearer " + token));
+                setToken(client, token);
             }
         } catch (IOException e) {
             throw new OperateException(e);