Handle malformed URI exceptions without breaking JMeter thread

src/main/java/com/blazemeter/jmeter/videostreaming/core/VideoStreamingHttpClient.java

@@ -19,6 +19,9 @@
 */
 public class VideoStreamingHttpClient extends HTTPHC4Impl {
 
+  private static final String NON_HTTP_RESPONSE_CODE = "Non HTTP response code";
+  private static final String NON_HTTP_RESPONSE_MESSAGE = "Non HTTP response message";
+
   private transient volatile boolean interrupted = false;
 
   private Map<String, String> headers = new HashMap<>();
@@ -53,13 +56,35 @@ public HTTPSampleResult downloadUri(URI uri) {
     if (interrupted) {
       throw new SamplerInterruptedException();
     }
+    if (uri == null || !uri.isAbsolute()) {
+      return buildInvalidUriResult(uri, "URI is not absolute");
+    }
     try {
       return sample(uri.toURL(), "GET", false, 0);
     } catch (MalformedURLException e) {
-      throw new IllegalArgumentException(e);
+      return buildInvalidUriResult(uri, e.getMessage());
     }
   }
 
+  /*
+  When the resolved URI can't be turned into an absolute URL (e.g. a dynamic master URL
+  variable resolved to an empty value or a relative path), we return a failed sample result
+  instead of throwing an uncaught IllegalArgumentException. This way the failure is recorded as
+  a measurable sample and handled by the normal download error path, rather than aborting the
+  sampler with a raw stack trace in the logs.
+  */
+  private HTTPSampleResult buildInvalidUriResult(URI uri, String detail) {
+    HTTPSampleResult result = new HTTPSampleResult();
+    result.sampleStart();
+    result.sampleEnd();
+    result.setSuccessful(false);
+    result.setResponseCode(
+        NON_HTTP_RESPONSE_CODE + ": " + IllegalArgumentException.class.getName());
+    result.setResponseMessage(NON_HTTP_RESPONSE_MESSAGE + ": "
+        + detail + " [" + (uri != null ? uri : "null") + "]");
+    return result;
+  }
+
   public void addHeader(String name, String value) {
     headers.put(name, value);
   }

src/main/java/com/blazemeter/jmeter/videostreaming/core/VideoStreamingSampler.java

@@ -82,6 +82,15 @@ public SampleResult sample() {
       sample(masterUri, baseSampler.getBandwidthSelector(), baseSampler.getResolutionSelector(),
           baseSampler.getAudioLanguage(), baseSampler.getSubtitleLanguage(),
           baseSampler.getPlaySecondsOrWarn());
+    } catch (IllegalArgumentException e) {
+      // the master URL (often a dynamic variable) is not a valid URI reference; record a failed
+      // sample instead of letting the exception abort the sampler with a raw stack trace
+      LOG.warn("Invalid master playlist URL '{}'", baseSampler.getMasterUrl(), e);
+      HTTPSampleResult result = new HTTPSampleResult();
+      result.sampleStart();
+      result.sampleEnd();
+      sampleResultProcessor.accept(buildPlaylistName(MASTER_TYPE_NAME),
+          baseSampler.errorResult(result, e));
     } catch (SamplerInterruptedException e) {
       LOG.debug("Sampler interrupted by JMeter", e);
     } catch (InterruptedException e) {

src/test/java/com/blazemeter/jmeter/videostreaming/core/VideoStreamingHttpClientTest.java

@@ -0,0 +1,57 @@
+package com.blazemeter.jmeter.videostreaming.core;
+
+import static org.assertj.core.api.Java6Assertions.assertThat;
+
+import com.blazemeter.jmeter.JMeterTestUtils;
+import com.blazemeter.jmeter.hls.logic.HlsSampler;
+import java.net.URI;
+import org.apache.jmeter.protocol.http.sampler.HTTPSampleResult;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class VideoStreamingHttpClientTest {
+
+  private VideoStreamingHttpClient httpClient;
+
+  @BeforeClass
+  public static void setupClass() {
+    JMeterTestUtils.setupJmeterEnv();
+  }
+
+  @Before
+  public void setup() {
+    httpClient = new VideoStreamingHttpClient(new HlsSampler());
+  }
+
+  /*
+   Reproduces the production scenario where a dynamic master URL variable resolves to a value
+   without a scheme (e.g. the JSON extractor default "C_hlsManifestPath_Not_Found"). Such a value
+   is a valid relative URI, so URI.create succeeds but URI.toURL() throws "URI is not absolute".
+   The client must not propagate that exception; it must return a failed sample result.
+   */
+  @Test
+  public void shouldReturnFailedResultWhenUriIsNotAbsolute() {
+    HTTPSampleResult result = httpClient.downloadUri(URI.create("C_hlsManifestPath_Not_Found"));
+    assertFailedResult(result);
+  }
+
+  @Test
+  public void shouldReturnFailedResultWhenUriIsRelativePath() {
+    HTTPSampleResult result = httpClient.downloadUri(URI.create("/relative/master.m3u8"));
+    assertFailedResult(result);
+  }
+
+  @Test
+  public void shouldReturnFailedResultWhenUriIsNull() {
+    HTTPSampleResult result = httpClient.downloadUri(null);
+    assertFailedResult(result);
+  }
+
+  private void assertFailedResult(HTTPSampleResult result) {
+    assertThat(result).isNotNull();
+    assertThat(result.isSuccessful()).isFalse();
+    assertThat(result.getResponseCode()).contains(IllegalArgumentException.class.getName());
+  }
+
+}

src/test/java/com/blazemeter/jmeter/videostreaming/hls/HlsSamplerTest.java

@@ -953,4 +953,16 @@ public void shouldFallbackToAtLeastOneSegmentWhenTargetDurationMissing() throws
         buildMediaSegmentSampleResult(5));
   }
 
+  @Test
+  public void shouldRecordFailedMasterSampleWhenMasterUrlIsNotValidUriReference() {
+    // unresolved dynamic variable (contains illegal URI characters) so URI.create itself fails
+    baseSampler.setMasterUrl("${C_hlsManifestPath}");
+    sampler.sample();
+    ArgumentCaptor<String> nameCaptor = ArgumentCaptor.forClass(String.class);
+    ArgumentCaptor<SampleResult> resultCaptor = ArgumentCaptor.forClass(SampleResult.class);
+    verify(sampleResultProcessor).accept(nameCaptor.capture(), resultCaptor.capture());
+    assertThat(nameCaptor.getValue()).isEqualTo("master playlist");
+    assertThat(resultCaptor.getValue().isSuccessful()).isFalse();
+  }
+
 }