avoid passing null and better classloader

src/main/java/jenkins/plugins/logstash/LogstashScriptProcessor.java

@@ -74,9 +74,9 @@ public LogstashScriptProcessor(SecureGroovyScript script, OutputStreamWriter con
     binding = new Binding();
     binding.setVariable("console", new BuildConsoleWrapper());
 
-    // not sure what the diff is compared to getClass().getClassLoader();
-    final Jenkins jenkins = Jenkins.getInstance();
-    classLoader = jenkins.getPluginManager().uberClassLoader;
+    // if users need access to types defined by any plugin we may decide to
+    // switch to Jenkins.getInstance().getPluginManager().uberClassLoader
+    classLoader = LogstashScriptProcessor.class.getClassLoader();
   }
 
   /**
@@ -102,7 +102,7 @@ public JSONObject process(JSONObject payload) throws Exception {
   @Override
   public JSONObject finish() throws Exception {
     buildLogPrintln("Tearing down Script Log Processor..");
-    return process(null);
+    return process(new JSONObject());
   }
 
   /**

src/main/java/jenkins/plugins/logstash/LogstashWriter.java

@@ -31,6 +31,7 @@
 import jenkins.model.Jenkins;
 import jenkins.plugins.logstash.persistence.BuildData;
 import jenkins.plugins.logstash.persistence.LogstashIndexerDao;
+import net.sf.json.JSONArray;
 import net.sf.json.JSONObject;
 import org.apache.commons.lang.StringUtils;
 import org.apache.commons.lang.exception.ExceptionUtils;
@@ -199,7 +200,7 @@ private void write(JSONObject payload) {
 
         logErrorMessage(msg);
       }
-      if (processedPayload != null) { writeRaw(processedPayload); }
+      if (payloadNeedsPersistence(processedPayload)) writeRaw(processedPayload);
     } else {
       writeRaw(payload);
     }
@@ -257,6 +258,16 @@ private void logErrorMessage(String msg) {
     }
   }
 
+  /**
+   * Check whether payload is something we are expected to persist
+   */
+  private Boolean payloadNeedsPersistence(JSONObject payload) {
+    if (payload != null) {
+      Object message = payload.opt("message");
+      return message != null && (message instanceof JSONArray) && !((JSONArray) message).isEmpty();
+    }
+    return false;
+  }
 
   /**
    * Signal payload processor that there will be no more lines
@@ -273,7 +284,7 @@ public void close() {
 
         logErrorMessage(msg);
       }
-      if (payload != null) writeRaw(payload);
+      if (payloadNeedsPersistence(payload)) writeRaw(payload);
     }
   }
 }

src/test/java/jenkins/plugins/logstash/LogstashOutputStreamTest.java

@@ -1,6 +1,7 @@
 package jenkins.plugins.logstash;
 
 import static org.hamcrest.core.StringContains.containsString;
+import static org.hamcrest.object.HasToString.hasToString;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThat;
 import static org.mockito.Mockito.*;
@@ -134,6 +135,6 @@ public void writerClosedBeforeDelegate() throws Exception {
     inOrder.verify(mockBuffer).close();
 
     // Verify results
-    assertEquals("Results don't match", "", buffer.toString());
+    assertThat(buffer, hasToString(""));
   }
 }

src/test/java/jenkins/plugins/logstash/LogstashWriterTest.java

@@ -306,9 +306,9 @@ public void writeProcessedSuccess() throws Exception {
     String goodMsg = "test message";
     String ignoredMsg = "ignored input";
     String scriptString =
-      "if (payload) {\n" +
+      "if (payload['message']) {\n" +
       "  if (payload['message'][0] =~ /" + ignoredMsg + "/) {\n" +
-      "    payload = null\n" +
+      "    payload.clear()\n" +
       "  } else {\n" +
       "    console.println('l');\n" +
       "  }\n" +