More information in test case

src/main/java/rocks/nifi/examples/processors/JsonProcessor.java

@@ -18,6 +18,7 @@ import java.util.concurrent.atomic.AtomicReference;
 import org.apache.commons.io.IOUtils;
 import org.apache.nifi.components.PropertyDescriptor;
 import org.apache.nifi.flowfile.FlowFile;
+import org.apache.nifi.logging.ProcessorLog;
 import org.apache.nifi.processor.AbstractProcessor;
 import org.apache.nifi.processor.ProcessContext;
 import org.apache.nifi.processor.ProcessSession;
@@ -39,10 +40,12 @@ import org.apache.nifi.processor.util.StandardValidators;
 @Tags({"JSON", "NIFI ROCKS"})
 @CapabilityDescription("Fetch value from json path.")
 public class JsonProcessor extends AbstractProcessor {
-    
+   
     private List<PropertyDescriptor> properties;
     private Set<Relationship> relationships;
     
+    public static final String MATCH_ATTR = "match";
+    
     public static final PropertyDescriptor JSON_PATH = new PropertyDescriptor.Builder()
             .name("Json Path")
             .required(true)
@@ -67,18 +70,32 @@ public class JsonProcessor extends AbstractProcessor {
     
     @Override
     public void onTrigger(ProcessContext context, ProcessSession session) throws ProcessException {
-        FlowFile flowfile = session.get();
+        final ProcessorLog log = this.getLogger();
         final AtomicReference<String> value = new AtomicReference<>();
         
+        FlowFile flowfile = session.get();
+        
         session.read(flowfile, new InputStreamCallback() {
             @Override
             public void process(InputStream in) throws IOException {
-                String json = IOUtils.toString(in);
-                String result = JsonPath.read(json, "$.hello");
-                value.set(result);
+                try{
+                    String json = IOUtils.toString(in);
+                    String result = JsonPath.read(json, "$.hello");
+                    value.set(result);
+                }catch(Exception ex){
+                    ex.printStackTrace();
+                    log.error("Failed to read json string.");
+                }
             }
         });
         
+        // Write the results to an attribute 
+        String results = value.get();
+        if(results != null && !results.isEmpty()){
+            flowfile = session.putAttribute(flowfile, "match", results);
+        }
+        
+        // To write the results back out ot flow file 
         flowfile = session.write(flowfile, new OutputStreamCallback() {
 
             @Override
@@ -87,8 +104,7 @@ public class JsonProcessor extends AbstractProcessor {
             }
         });
         
-        session.transfer(flowfile, SUCCESS);
-                                                                                                                                                                                                                                                                                                                                                                                                         
+        session.transfer(flowfile, SUCCESS);                                                                                                                                                                                                                                                                                                                                                                                                 
     }
     
     @Override

src/test/java/rocks/nifi/examples/processors/JsonProcessorTest.java

@@ -6,13 +6,15 @@
 package rocks.nifi.examples.processors;
 
 import java.io.ByteArrayInputStream;
+import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;
 import java.util.Set;
+import org.apache.commons.io.IOUtils;
 import org.apache.nifi.processor.ProcessContext;
 import org.apache.nifi.processor.ProcessSession;
 import org.apache.nifi.processor.ProcessorInitializationContext;
-import org.apache.nifi.processor.Relationship;
+import org.apache.nifi.util.MockFlowFile;
 import org.apache.nifi.util.TestRunner;
 import org.apache.nifi.util.TestRunners;
 import org.junit.Test;
@@ -28,18 +30,36 @@ public class JsonProcessorTest {
      * Test of onTrigger method, of class JsonProcessor.
      */
     @org.junit.Test
-    public void testOnTrigger() {
+    public void testOnTrigger() throws IOException {
+        // Content to be mock a json file
         InputStream content = new ByteArrayInputStream("{\"hello\":\"nifi rocks\"}".getBytes());
         
+        // Generate a test runner to mock a processor in a flow
         TestRunner runner = TestRunners.newTestRunner(new JsonProcessor());
+        
+        // Add properites
         runner.setProperty(JsonProcessor.JSON_PATH, "$.hello");
+        
+        // Add the content to the runner
         runner.enqueue(content);
-        runner.run();
         
+        // Run the enqueued content, it also takes an int = number of contents queued
+        runner.run(1);
+        
+        // All results were processed with out failure
         runner.assertQueueEmpty();
         
-        // TODO review the generated test code and remove the default call to fail.
-        // fail("The test case is a prototype.");
+        // If you need to read or do aditional tests on results you can access the content
+        List<MockFlowFile> results = runner.getFlowFilesForRelationship(JsonProcessor.SUCCESS);
+        assertTrue("1 match", results.size() == 1);
+        MockFlowFile result = results.get(0);
+        String resultValue = new String(runner.getContentAsByteArray(result));
+        System.out.println("Match: " + IOUtils.toString(runner.getContentAsByteArray(result)));
+        
+        // Test attributes and content
+        result.assertAttributeEquals(JsonProcessor.MATCH_ATTR, "nifi rocks");
+        result.assertContentEquals("nifi rocks");
+        
     }
     
 }