OAK-11452 : fixed a potential NPE in toString()

Author: Rishabh Kumar

oak-store-document/src/main/java/org/apache/jackrabbit/oak/plugins/document/FullGCStatsCollectorImpl.java

@@ -248,13 +248,13 @@ public void maxAge(long maxAge) {
     @Override
     public String toString() {
         return "FullGCStatsCollectorImpl{" +
-                "enabled=" + enabled.getValue() +
-                ", mode=" + mode.getValue() +
-                ", delayFactor=" + delayFactor.getValue() +
-                ", batchSize=" + batchSize.getValue() +
-                ", progressSize=" + progressSize.getValue() +
-                ", embeddedVerificationEnabled=" + embeddedVerificationEnabled.getValue() +
-                ", maxAge=" + maxAge.getValue() +
+                "enabled=" + getValue(enabled, "false") +
+                ", mode=" + getValue(mode, "0") +
+                ", delayFactor=" + getValue(delayFactor, "0.0") +
+                ", batchSize=" + getValue(batchSize, "0") +
+                ", progressSize=" + getValue(progressSize, "0") +
+                ", embeddedVerificationEnabled=" + getValue(embeddedVerificationEnabled, "false") +
+                ", maxAge=" + getValue(maxAge, "0") +
                 ", readDoc=" + readDoc.getCount() +
                 ", candidateRevisions=" + mapToString(candidateRevisions) +
                 ", candidateInternalRevisions=" + mapToString(candidateInternalRevisions) +
@@ -308,4 +308,9 @@ private static String qualifiedName(String metricName) {
     private MeterStats getMeter(Map<GCPhase, MeterStats> map, GCPhase phase, String name) {
         return map.computeIfAbsent(phase, p -> meter(provider, name + "." + p.name()));
     }
+
+    private String getValue(final GaugeStats<?> gaugeStats, final String defaultValue) {
+        return gaugeStats != null ? String.valueOf(gaugeStats.getValue()) : defaultValue;
+    }
+
 }

oak-store-document/src/test/java/org/apache/jackrabbit/oak/plugins/document/FullGCStatsCollectorImplTest.java

@@ -293,6 +293,19 @@ public void getFullGcOsgiConfigs() {
         assertTrue(stats.toString().contains("mode=4"));
     }
 
+    @Test
+    public void getFullGcOsgiConfigsDefaults() {
+
+        // update the value
+        assertTrue(stats.toString().contains("maxAge=0"));
+        assertTrue(stats.toString().contains("enabled=false"));
+        assertTrue(stats.toString().contains("embeddedVerificationEnabled=false"));
+        assertTrue(stats.toString().contains("progressSize=0"));
+        assertTrue(stats.toString().contains("batchSize=0"));
+        assertTrue(stats.toString().contains("delayFactor=0.0"));
+        assertTrue(stats.toString().contains("mode=0"));
+    }
+
     // helper methods
 
     private void assertTimer(long expected, String name) {