Remove System.out.println and Throwable.printStackTrace from tests

13 files changed, 66 insertions, 80 deletions

diff --git a/core/src/test/java/org/elasticsearch/common/xcontent/builder/XContentBuilderTests.java b/core/src/test/java/org/elasticsearch/common/xcontent/builder/XContentBuilderTests.java
index 9129e3c05b..36b16d6a17 100644
--- a/core/src/test/java/org/elasticsearch/common/xcontent/builder/XContentBuilderTests.java
+++ b/core/src/test/java/org/elasticsearch/common/xcontent/builder/XContentBuilderTests.java
@@ -166,7 +166,7 @@ public class XContentBuilderTests extends ESTestCase {
 
         byte[] data = bos.bytes().toBytes();
         String sData = new String(data, "UTF8");
-        System.out.println("DATA: " + sData);
+        assertThat(sData, equalTo("{\"name\":\"something\", source : { test : \"value\" },\"name2\":\"something2\"}"));
     }
 
     public void testFieldCaseConversion() throws Exception {
diff --git a/core/src/test/java/org/elasticsearch/http/netty/NettyHttpServerPipeliningTests.java b/core/src/test/java/org/elasticsearch/http/netty/NettyHttpServerPipeliningTests.java
index 6afe8a0aef..5d4330ec5c 100644
--- a/core/src/test/java/org/elasticsearch/http/netty/NettyHttpServerPipeliningTests.java
+++ b/core/src/test/java/org/elasticsearch/http/netty/NettyHttpServerPipeliningTests.java
@@ -181,7 +181,7 @@ public class NettyHttpServerPipeliningTests extends ESTestCase {
 
         @Override
         public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
-            e.getCause().printStackTrace();
+            logger.info("Caught exception", e.getCause());
             e.getChannel().close();
         }
     }
diff --git a/core/src/test/java/org/elasticsearch/index/translog/TranslogTests.java b/core/src/test/java/org/elasticsearch/index/translog/TranslogTests.java
index 337d91356b..984908ad9d 100644
--- a/core/src/test/java/org/elasticsearch/index/translog/TranslogTests.java
+++ b/core/src/test/java/org/elasticsearch/index/translog/TranslogTests.java
@@ -1491,7 +1491,7 @@ public class TranslogTests extends ESTestCase {
                 if (writtenOperations.size() != snapshot.totalOperations()) {
                     for (int i = 0; i < threadCount; i++) {
                         if (threadExceptions[i] != null) {
-                            threadExceptions[i].printStackTrace();
+                            logger.info("Translog exception", threadExceptions[i]);
                         }
                     }
                 }
diff --git a/core/src/test/java/org/elasticsearch/indices/IndexingMemoryControllerTests.java b/core/src/test/java/org/elasticsearch/indices/IndexingMemoryControllerTests.java
index 4f08c49744..3316b52be2 100644
--- a/core/src/test/java/org/elasticsearch/indices/IndexingMemoryControllerTests.java
+++ b/core/src/test/java/org/elasticsearch/indices/IndexingMemoryControllerTests.java
@@ -281,7 +281,7 @@ public class IndexingMemoryControllerTests extends ESSingleNodeTestCase {
         controller.assertNotThrottled(shard0);
         controller.assertThrottled(shard1);
 
-        System.out.println("TEST: now index more");
+        logger.info("--> Indexing more data");
 
         // More indexing to shard0
         controller.simulateIndexing(shard0);
diff --git a/core/src/test/java/org/elasticsearch/percolator/ConcurrentPercolatorIT.java b/core/src/test/java/org/elasticsearch/percolator/ConcurrentPercolatorIT.java
index f2493d85e8..1cf2ef035b 100644
--- a/core/src/test/java/org/elasticsearch/percolator/ConcurrentPercolatorIT.java
+++ b/core/src/test/java/org/elasticsearch/percolator/ConcurrentPercolatorIT.java
@@ -54,7 +54,7 @@ import static org.hamcrest.Matchers.nullValue;
  *
  */
 public class ConcurrentPercolatorIT extends ESIntegTestCase {
-    public void testSimpleConcurrentPercolator() throws Exception {
+    public void testSimpleConcurrentPercolator() throws Throwable {
         // We need to index a document / define mapping, otherwise field1 doesn't get recognized as number field.
         // If we don't do this, then 'test2' percolate query gets parsed as a TermQuery and not a RangeQuery.
         // The percolate api doesn't parse the doc if no queries have registered, so it can't lazily create a mapping
@@ -143,9 +143,8 @@ public class ConcurrentPercolatorIT extends ESIntegTestCase {
 
         Throwable assertionError = exceptionHolder.get();
         if (assertionError != null) {
-            assertionError.printStackTrace();
+            throw assertionError;
         }
-        assertThat(assertionError + " should be null", assertionError, nullValue());
     }
 
     public void testConcurrentAddingAndPercolating() throws Exception {
diff --git a/core/src/test/java/org/elasticsearch/search/aggregations/BasePipelineAggregationTestCase.java b/core/src/test/java/org/elasticsearch/search/aggregations/BasePipelineAggregationTestCase.java
index f180ab5716..667cc9008a 100644
--- a/core/src/test/java/org/elasticsearch/search/aggregations/BasePipelineAggregationTestCase.java
+++ b/core/src/test/java/org/elasticsearch/search/aggregations/BasePipelineAggregationTestCase.java
@@ -218,7 +218,7 @@ public abstract class BasePipelineAggregationTestCase<AF extends PipelineAggrega
         AF testAgg = createTestAggregatorFactory();
         AggregatorFactories.Builder factoriesBuilder = AggregatorFactories.builder().skipResolveOrder().addPipelineAggregator(testAgg);
         String contentString = factoriesBuilder.toString();
-        System.out.println(contentString);
+        logger.info("Content string: {}", contentString);
         XContentParser parser = XContentFactory.xContent(contentString).createParser(contentString);
         QueryParseContext parseContext = new QueryParseContext(queriesRegistry);
         parseContext.reset(parser);
diff --git a/core/src/test/java/org/elasticsearch/search/fetch/FetchSubPhasePluginIT.java b/core/src/test/java/org/elasticsearch/search/fetch/FetchSubPhasePluginIT.java
index 3159217f17..071f737538 100644
--- a/core/src/test/java/org/elasticsearch/search/fetch/FetchSubPhasePluginIT.java
+++ b/core/src/test/java/org/elasticsearch/search/fetch/FetchSubPhasePluginIT.java
@@ -27,6 +27,7 @@ import org.elasticsearch.action.search.SearchResponse;
 import org.elasticsearch.action.termvectors.TermVectorsRequest;
 import org.elasticsearch.action.termvectors.TermVectorsResponse;
 import org.elasticsearch.common.Priority;
+import org.elasticsearch.common.logging.ESLoggerFactory;
 import org.elasticsearch.common.xcontent.XContentBuilder;
 import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.termvectors.TermVectorsService;
@@ -173,7 +174,7 @@ public class FetchSubPhasePluginIT extends ESIntegTestCase {
                 }
                 hitField.values().add(tv);
             } catch (IOException e) {
-                e.printStackTrace();
+                ESLoggerFactory.getLogger(FetchSubPhasePluginIT.class.getName()).info("Swallowed exception", e);
             }
         }
     }
diff --git a/core/src/test/java/org/elasticsearch/search/geo/GeoFilterIT.java b/core/src/test/java/org/elasticsearch/search/geo/GeoFilterIT.java
index 8f04bd7275..83e89592b8 100644
--- a/core/src/test/java/org/elasticsearch/search/geo/GeoFilterIT.java
+++ b/core/src/test/java/org/elasticsearch/search/geo/GeoFilterIT.java
@@ -19,6 +19,7 @@
 
 package org.elasticsearch.search.geo;
 
+import org.elasticsearch.common.logging.ESLoggerFactory;
 import org.locationtech.spatial4j.context.SpatialContext;
 import org.locationtech.spatial4j.distance.DistanceUtils;
 import org.locationtech.spatial4j.exception.InvalidShapeException;
@@ -560,7 +561,7 @@ public class GeoFilterIT extends ESIntegTestCase {
             strategy.makeQuery(args);
             return true;
         } catch (UnsupportedSpatialOperation e) {
-            e.printStackTrace();
+            ESLoggerFactory.getLogger(GeoFilterIT.class.getName()).info("Unsupported spatial operation {}", e, relation);
             return false;
         }
     }
diff --git a/core/src/test/java/org/elasticsearch/search/highlight/HighlightBuilderTests.java b/core/src/test/java/org/elasticsearch/search/highlight/HighlightBuilderTests.java
index b8f775639f..84b3b5a36a 100644
--- a/core/src/test/java/org/elasticsearch/search/highlight/HighlightBuilderTests.java
+++ b/core/src/test/java/org/elasticsearch/search/highlight/HighlightBuilderTests.java
@@ -400,7 +400,6 @@ public class HighlightBuilderTests extends ESTestCase {
         context.reset(parser);
         highlightBuilder = HighlightBuilder.PROTOTYPE.fromXContent(context);
         assertEquals("expected HighlightBuilder with field", new HighlightBuilder().field(new Field("foo")), highlightBuilder);
-        System.out.println(Math.log(1/(double)(1+1)) + 1.0);
     }
 
     /**
diff --git a/core/src/test/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java b/core/src/test/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
index f65ce317d7..454fa836b8 100644
--- a/core/src/test/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
+++ b/core/src/test/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
@@ -137,8 +137,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
                 try {
                     channel.sendResponse(new StringMessageResponse("hello " + request.message));
                 } catch (IOException e) {
-                    e.printStackTrace();
-                    assertThat(e.getMessage(), false, equalTo(true));
+                    logger.error("Unexpected failure", e);
+                    fail(e.getMessage());
                 }
             }
         });
@@ -162,8 +162,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
                     @Override
                     public void handleException(TransportException exp) {
-                        exp.printStackTrace();
-                        assertThat("got exception instead of a response: " + exp.getMessage(), false, equalTo(true));
+                        logger.error("Unexpected failure", exp);
+                        fail("got exception instead of a response: " + exp.getMessage());
                     }
                 });
 
@@ -193,8 +193,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
                     @Override
                     public void handleException(TransportException exp) {
-                        exp.printStackTrace();
-                        assertThat("got exception instead of a response: " + exp.getMessage(), false, equalTo(true));
+                        logger.error("Unexpected failure", exp);
+                        fail("got exception instead of a response: " + exp.getMessage());
                     }
                 });
 
@@ -218,7 +218,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
                 threadPool.getThreadContext().putHeader("test.pong.user", "pong_user");
                 channel.sendResponse(response);
             } catch (IOException e) {
-                assertThat(e.getMessage(), false, equalTo(true));
+                logger.error("Unexpected failure", e);
+                fail(e.getMessage());
             }
         });
         final Object context = new Object();
@@ -245,7 +246,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
             @Override
             public void handleException(TransportException exp) {
-                assertThat("got exception instead of a response: " + exp.getMessage(), false, equalTo(true));
+                logger.error("Unexpected failure", exp);
+                fail("got exception instead of a response: " + exp.getMessage());
             }
         };
         StringMessageRequest ping = new StringMessageRequest("ping");
@@ -317,8 +319,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
                 try {
                     channel.sendResponse(TransportResponse.Empty.INSTANCE, TransportResponseOptions.builder().withCompress(true).build());
                 } catch (IOException e) {
-                    e.printStackTrace();
-                    assertThat(e.getMessage(), false, equalTo(true));
+                    logger.error("Unexpected failure", e);
+                    fail(e.getMessage());
                 }
             }
         });
@@ -341,8 +343,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
                     @Override
                     public void handleException(TransportException exp) {
-                        exp.printStackTrace();
-                        assertThat("got exception instead of a response: " + exp.getMessage(), false, equalTo(true));
+                        logger.error("Unexpected failure", exp);
+                        fail("got exception instead of a response: " + exp.getMessage());
                     }
                 });
 
@@ -364,8 +366,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
                 try {
                     channel.sendResponse(new StringMessageResponse("hello " + request.message), TransportResponseOptions.builder().withCompress(true).build());
                 } catch (IOException e) {
-                    e.printStackTrace();
-                    assertThat(e.getMessage(), false, equalTo(true));
+                    logger.error("Unexpected failure", e);
+                    fail(e.getMessage());
                 }
             }
         });
@@ -389,8 +391,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
                     @Override
                     public void handleException(TransportException exp) {
-                        exp.printStackTrace();
-                        assertThat("got exception instead of a response: " + exp.getMessage(), false, equalTo(true));
+                        logger.error("Unexpected failure", exp);
+                        fail("got exception instead of a response: " + exp.getMessage());
                     }
                 });
 
@@ -552,8 +554,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
                 try {
                     channel.sendResponse(new StringMessageResponse("hello " + request.message));
                 } catch (IOException e) {
-                    e.printStackTrace();
-                    assertThat(e.getMessage(), false, equalTo(true));
+                    logger.error("Unexpected failure", e);
+                    fail(e.getMessage());
                 }
             }
         });
@@ -613,7 +615,7 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
                         @Override
                         public void handleException(TransportException exp) {
-                            exp.printStackTrace();
+                            logger.error("Unexpected failure", exp);
                             fail("got exception instead of a response for " + counter + ": " + exp.getDetailedMessage());
                         }
                     });
@@ -959,8 +961,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
             @Override
             public void handleException(TransportException exp) {
-                exp.printStackTrace();
-                fail();
+                logger.error("Unexpected failure", exp);
+                fail("got exception instead of a response: " + exp.getMessage());
             }
 
             @Override
@@ -1000,8 +1002,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
             @Override
             public void handleException(TransportException exp) {
-                exp.printStackTrace();
-                fail();
+                logger.error("Unexpected failure", exp);
+                fail("got exception instead of a response: " + exp.getMessage());
             }
 
             @Override
@@ -1044,8 +1046,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
             @Override
             public void handleException(TransportException exp) {
-                exp.printStackTrace();
-                fail();
+                logger.error("Unexpected failure", exp);
+                fail("got exception instead of a response: " + exp.getMessage());
             }
 
             @Override
@@ -1084,8 +1086,8 @@ public abstract class AbstractSimpleTransportTestCase extends ESTestCase {
 
             @Override
             public void handleException(TransportException exp) {
-                exp.printStackTrace();
-                fail();
+                logger.error("Unexpected failure", exp);
+                fail("got exception instead of a response: " + exp.getMessage());
             }
 
             @Override
diff --git a/core/src/test/java/org/elasticsearch/transport/netty/NettyScheduledPingTests.java b/core/src/test/java/org/elasticsearch/transport/netty/NettyScheduledPingTests.java
index 3d6ff1cd06..c812a67845 100644
--- a/core/src/test/java/org/elasticsearch/transport/netty/NettyScheduledPingTests.java
+++ b/core/src/test/java/org/elasticsearch/transport/netty/NettyScheduledPingTests.java
@@ -86,8 +86,8 @@ public class NettyScheduledPingTests extends ESTestCase {
                 try {
                     channel.sendResponse(TransportResponse.Empty.INSTANCE, TransportResponseOptions.EMPTY);
                 } catch (IOException e) {
-                    e.printStackTrace();
-                    assertThat(e.getMessage(), false, equalTo(true));
+                    logger.error("Unexpected failure", e);
+                    fail(e.getMessage());
                 }
             }
         });
@@ -113,8 +113,8 @@ public class NettyScheduledPingTests extends ESTestCase {
 
                         @Override
                         public void handleException(TransportException exp) {
-                            exp.printStackTrace();
-                            assertThat("got exception instead of a response: " + exp.getMessage(), false, equalTo(true));
+                            logger.error("Unexpected failure", exp);
+                            fail("got exception instead of a response: " + exp.getMessage());
                         }
                     }).txGet();
         }
diff --git a/core/src/test/java/org/elasticsearch/versioning/ConcurrentDocumentOperationIT.java b/core/src/test/java/org/elasticsearch/versioning/ConcurrentDocumentOperationIT.java
index bb8636d36e..6b69a038a0 100644
--- a/core/src/test/java/org/elasticsearch/versioning/ConcurrentDocumentOperationIT.java
+++ b/core/src/test/java/org/elasticsearch/versioning/ConcurrentDocumentOperationIT.java
@@ -54,7 +54,7 @@ public class ConcurrentDocumentOperationIT extends ESIntegTestCase {
 
                 @Override
                 public void onFailure(Throwable e) {
-                    e.printStackTrace();
+                    logger.error("Unexpected exception while indexing", e);
                     failure.set(e);
                     latch.countDown();
                 }
diff --git a/core/src/test/java/org/elasticsearch/versioning/SimpleVersioningIT.java b/core/src/test/java/org/elasticsearch/versioning/SimpleVersioningIT.java
index 3432411b22..4e319c65ba 100644
--- a/core/src/test/java/org/elasticsearch/versioning/SimpleVersioningIT.java
+++ b/core/src/test/java/org/elasticsearch/versioning/SimpleVersioningIT.java
@@ -354,9 +354,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
         switch (random.nextInt(6)) {
             case 0:
                 // random simple
-                if (VERBOSE) {
-                    System.out.println("TEST: use random simple ids");
-                }
+                logger.info("--> use random simple ids");
                 ids = new IDSource() {
                     @Override
                     public String next() {
@@ -366,9 +364,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
                 break;
             case 1:
                 // random realistic unicode
-                if (VERBOSE) {
-                    System.out.println("TEST: use random realistic unicode ids");
-                }
+                logger.info("--> use random realistic unicode ids");
                 ids = new IDSource() {
                     @Override
                     public String next() {
@@ -378,9 +374,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
                 break;
             case 2:
                 // sequential
-                if (VERBOSE) {
-                    System.out.println("TEST: use seuquential ids");
-                }
+                logger.info("--> use sequential ids");
                 ids = new IDSource() {
                     int upto;
 
@@ -392,9 +386,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
                 break;
             case 3:
                 // zero-pad sequential
-                if (VERBOSE) {
-                    System.out.println("TEST: use zero-pad seuquential ids");
-                }
+                logger.info("--> use zero-padded sequential ids");
                 ids = new IDSource() {
                     final int radix = TestUtil.nextInt(random, Character.MIN_RADIX, Character.MAX_RADIX);
                     final String zeroPad = String.format(Locale.ROOT, "%0" + TestUtil.nextInt(random, 4, 20) + "d", 0);
@@ -409,9 +401,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
                 break;
             case 4:
                 // random long
-                if (VERBOSE) {
-                    System.out.println("TEST: use random long ids");
-                }
+                logger.info("--> use random long ids");
                 ids = new IDSource() {
                     final int radix = TestUtil.nextInt(random, Character.MIN_RADIX, Character.MAX_RADIX);
                     int upto;
@@ -424,9 +414,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
                 break;
             case 5:
                 // zero-pad random long
-                if (VERBOSE) {
-                    System.out.println("TEST: use zero-pad random long ids");
-                }
+                logger.info("--> use zero-padded random long ids");
                 ids = new IDSource() {
                     final int radix = TestUtil.nextInt(random, Character.MIN_RADIX, Character.MAX_RADIX);
                     final String zeroPad = String.format(Locale.ROOT, "%015d", 0);
@@ -539,9 +527,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
             idPrefix = "";
         } else {
             idPrefix = TestUtil.randomSimpleString(random);
-            if (VERBOSE) {
-                System.out.println("TEST: use id prefix: " + idPrefix);
-            }
+            logger.debug("--> use id prefix {}", idPrefix);
         }
 
         int numIDs;
@@ -564,9 +550,7 @@ public class SimpleVersioningIT extends ESIntegTestCase {
         final IDAndVersion[] idVersions = new IDAndVersion[TestUtil.nextInt(random, numIDs / 2, numIDs * (TEST_NIGHTLY ? 8 : 2))];
         final Map<String, IDAndVersion> truth = new HashMap<>();
 
-        if (VERBOSE) {
-            System.out.println("TEST: use " + numIDs + " ids; " + idVersions.length + " operations");
-        }
+        logger.debug("--> use {} ids; {} operations", numIDs, idVersions.length);
 
         for (int i = 0; i < idVersions.length; i++) {
 
@@ -596,10 +580,9 @@ public class SimpleVersioningIT extends ESIntegTestCase {
             idVersions[i] = x;
         }
 
-        if (VERBOSE) {
-            for (IDAndVersion idVersion : idVersions) {
-                System.out.println("id=" + idVersion.id + " version=" + idVersion.version + " delete?=" + idVersion.delete + " truth?=" + (truth.get(idVersion.id) == idVersion));
-            }
+        for (IDAndVersion idVersion : idVersions) {
+            logger.debug("--> id={} version={} delete?={} truth?={}", idVersion.id, idVersion.version, idVersion.delete,
+                truth.get(idVersion.id) == idVersion);
         }
 
         final AtomicInteger upto = new AtomicInteger();
@@ -623,8 +606,8 @@ public class SimpleVersioningIT extends ESIntegTestCase {
                             if (index >= idVersions.length) {
                                 break;
                             }
-                            if (VERBOSE && index % 100 == 0) {
-                                System.out.println(Thread.currentThread().getName() + ": index=" + index);
+                            if (index % 100 == 0) {
+                                logger.trace("{}: index={}", Thread.currentThread().getName(), index);
                             }
                             IDAndVersion idVersion = idVersions[index];
 
@@ -657,18 +640,18 @@ public class SimpleVersioningIT extends ESIntegTestCase {
                             idVersion.indexFinishTime = System.nanoTime() - startTime;
 
                             if (threadRandom.nextInt(100) == 7) {
-                                System.out.println(threadID + ": TEST: now refresh at " + (System.nanoTime() - startTime));
+                                logger.trace("--> {}: TEST: now refresh at {}", threadID, System.nanoTime() - startTime);
                                 refresh();
-                                System.out.println(threadID + ": TEST: refresh done at " + (System.nanoTime() - startTime));
+                                logger.trace("--> {}: TEST: refresh done at {}", threadID, System.nanoTime() - startTime);
                             }
                             if (threadRandom.nextInt(100) == 7) {
-                                System.out.println(threadID + ": TEST: now flush at " + (System.nanoTime() - startTime));
+                                logger.trace("--> {}: TEST: now flush at {}", threadID, System.nanoTime() - startTime);
                                 try {
                                     flush();
                                 } catch (FlushNotAllowedEngineException fnaee) {
                                     // OK
                                 }
-                                System.out.println(threadID + ": TEST: flush done at " + (System.nanoTime() - startTime));
+                                logger.trace("--> {}: TEST: flush done at {}", threadID, System.nanoTime() - startTime);
                             }
                         }
                     } catch (Exception e) {
@@ -696,16 +679,17 @@ public class SimpleVersioningIT extends ESIntegTestCase {
             }
             long actualVersion = client().prepareGet("test", "type", id).execute().actionGet().getVersion();
             if (actualVersion != expected) {
-                System.out.println("FAILED: idVersion=" + idVersion + " actualVersion=" + actualVersion);
+                logger.error("--> FAILED: idVersion={} actualVersion= {}", idVersion, actualVersion);
                 failed = true;
             }
         }
 
         if (failed) {
-            System.out.println("All versions:");
+            StringBuilder sb = new StringBuilder();
             for (int i = 0; i < idVersions.length; i++) {
-                System.out.println("i=" + i + " " + idVersions[i]);
+                sb.append("i=").append(i).append(" ").append(idVersions[i]).append(System.lineSeparator());
             }
+            logger.error("All versions: {}", sb);
             fail("wrong versions for some IDs");
         }
     }