Apply consistent Exception variable names to all catch blocks.

We now consistently align with the core Spring Framework's use of 'ex' as the variable name for Exceptions handled in catch blocks, and 'ignore' for all Exceptions thrown, but ignored by framework code. Both 'ex' and 'ignore' were appropriately used based on the context and nautre of the Exception handler in the catch block.

Additionally, we use the 'expected' variable name for Exception thrown in tests where the thrown Exception is the expected outcome of the test case.

Only 1 exception exists to these name conventions, and that is 'nested', which was necessarily used in ScanCursor due to the nested try-catch blocks.

Applied consistent use of String.format(..) to Exception messages requiring formatting.

Formatted catch block according to source code formatting style.

Closes #2748
Original pull request: #2749

Author: jxblum

src/main/java/org/springframework/data/redis/cache/DefaultRedisCacheWriter.java

@@ -377,13 +377,14 @@ private void checkAndPotentiallyWaitUntilUnlocked(String name, RedisConnection c
 			while (doCheckLock(name, connection)) {
 				Thread.sleep(this.sleepTime.toMillis());
 			}
-		} catch (InterruptedException cause) {
+		} catch (InterruptedException ex) {
 
 			// Re-interrupt current Thread to allow other participants to react.
 			Thread.currentThread().interrupt();
 
-			throw new PessimisticLockingFailureException(String.format("Interrupted while waiting to unlock cache %s", name),
-					cause);
+			String message = String.format("Interrupted while waiting to unlock cache %s", name);
+
+			throw new PessimisticLockingFailureException(message, ex);
 		} finally {
 			this.statistics.incLockTime(name, System.nanoTime() - lockWaitTimeNs);
 		}

src/main/java/org/springframework/data/redis/cache/RedisCache.java

@@ -189,8 +189,8 @@ protected <T> T loadCacheValue(Object key, Callable<T> valueLoader) {
 
 		try {
 			value = valueLoader.call();
-		} catch (Exception cause) {
-			throw new ValueRetrievalException(key, valueLoader, cause);
+		} catch (Exception ex) {
+			throw new ValueRetrievalException(key, valueLoader, ex);
 		}
 
 		put(key, value);
@@ -425,14 +425,14 @@ protected String convertKey(Object key) {
 		if (conversionService.canConvert(source, TypeDescriptor.valueOf(String.class))) {
 			try {
 				return conversionService.convert(key, String.class);
-			} catch (ConversionFailedException cause) {
+			} catch (ConversionFailedException ex) {
 
 				// May fail if the given key is a collection
 				if (isCollectionLikeOrMap(source)) {
 					return convertCollectionLikeOrMapKey(key, source);
 				}
 
-				throw cause;
+				throw ex;
 			}
 		}
 

src/main/java/org/springframework/data/redis/connection/AbstractRedisConnection.java

@@ -114,8 +114,8 @@ public void close() throws DataAccessException {
 
 			try {
 				connection.close();
-			} catch (IOException e) {
-				LOGGER.info("Failed to close sentinel connection", e);
+			} catch (IOException ex) {
+				LOGGER.info("Failed to close sentinel connection", ex);
 			}
 		}
 	}

src/main/java/org/springframework/data/redis/connection/ClusterCommandExecutor.java

@@ -131,10 +131,11 @@ private <S, T> NodeResult<T> executeCommandOnSingleNode(ClusterCommandCallback<S
 
 		if (redirectCount > this.maxRedirects) {
 
-			throw new TooManyClusterRedirectionsException(String.format(
-					"Cannot follow Cluster Redirects over more than %s legs; "
-							+ "Consider increasing the number of redirects to follow; Current value is: %s.",
-					redirectCount, this.maxRedirects));
+			String message = String.format("Cannot follow Cluster Redirects over more than %s legs; "
+					+ "Consider increasing the number of redirects to follow; Current value is: %s.",
+							redirectCount, this.maxRedirects);
+
+			throw new TooManyClusterRedirectionsException(message);
 		}
 
 		RedisClusterNode nodeToUse = lookupNode(node);
@@ -145,15 +146,19 @@ private <S, T> NodeResult<T> executeCommandOnSingleNode(ClusterCommandCallback<S
 
 		try {
 			return new NodeResult<>(node, commandCallback.doInCluster(client));
-		} catch (RuntimeException cause) {
+		} catch (RuntimeException ex) {
 
-			RuntimeException translatedException = convertToDataAccessException(cause);
+			RuntimeException translatedException = convertToDataAccessException(ex);
 
 			if (translatedException instanceof ClusterRedirectException clusterRedirectException) {
-				return executeCommandOnSingleNode(commandCallback, topologyProvider.getTopology().lookup(
-						clusterRedirectException.getTargetHost(), clusterRedirectException.getTargetPort()), redirectCount + 1);
+
+				String targetHost = clusterRedirectException.getTargetHost();
+				int targetPort = clusterRedirectException.getTargetPort();
+				RedisClusterNode clusterNode = topologyProvider.getTopology().lookup(targetHost, targetPort);
+
+				return executeCommandOnSingleNode(commandCallback, clusterNode, redirectCount + 1);
 			} else {
-				throw translatedException != null ? translatedException : cause;
+				throw translatedException != null ? translatedException : ex;
 			}
 		} finally {
 			this.resourceProvider.returnResourceForSpecificNode(nodeToUse, client);
@@ -172,8 +177,8 @@ private RedisClusterNode lookupNode(RedisClusterNode node) {
 
 		try {
 			return topologyProvider.getTopology().lookup(node);
-		} catch (ClusterStateFailureException cause) {
-			throw new IllegalArgumentException(String.format("Node %s is unknown to cluster", node), cause);
+		} catch (ClusterStateFailureException ex) {
+			throw new IllegalArgumentException(String.format("Node %s is unknown to cluster", node), ex);
 		}
 	}
 
@@ -209,8 +214,8 @@ public <S, T> MultiNodeResult<T> executeCommandAsyncOnNodes(ClusterCommandCallba
 		for (RedisClusterNode node : nodes) {
 			try {
 				resolvedRedisClusterNodes.add(topology.lookup(node));
-			} catch (ClusterStateFailureException cause) {
-				throw new IllegalArgumentException(String.format("Node %s is unknown to cluster", node), cause);
+			} catch (ClusterStateFailureException ex) {
+				throw new IllegalArgumentException(String.format("Node %s is unknown to cluster", node), ex);
 			}
 		}
 
@@ -249,13 +254,13 @@ <T> MultiNodeResult<T> collectResults(Map<NodeExecution, Future<NodeResult<T>>>
 					}
 
 					entryIterator.remove();
-				} catch (ExecutionException exception) {
+				} catch (ExecutionException ex) {
 					entryIterator.remove();
-					exceptionCollector.addException(nodeExecution, exception.getCause());
+					exceptionCollector.addException(nodeExecution, ex.getCause());
 				} catch (TimeoutException ignore) {
-				} catch (InterruptedException exception) {
+				} catch (InterruptedException ex) {
 					Thread.currentThread().interrupt();
-					exceptionCollector.addException(nodeExecution, exception);
+					exceptionCollector.addException(nodeExecution, ex);
 					break OUT;
 				}
 			}
@@ -316,11 +321,11 @@ private <S, T> NodeResult<T> executeMultiKeyCommandOnSingleNode(MultiKeyClusterC
 
 		try {
 			return new NodeResult<>(node, commandCallback.doInCluster(client, key), key);
-		} catch (RuntimeException cause) {
+		} catch (RuntimeException ex) {
 
-			RuntimeException translatedException = convertToDataAccessException(cause);
+			RuntimeException translatedException = convertToDataAccessException(ex);
 
-			throw translatedException != null ? translatedException : cause;
+			throw translatedException != null ? translatedException : ex;
 		} finally {
 			this.resourceProvider.returnResourceForSpecificNode(node, client);
 		}

src/main/java/org/springframework/data/redis/connection/RedisNode.java

@@ -101,7 +101,7 @@ public static RedisNode fromString(String hostPortString) {
 		int port = -1;
 		try {
 			port = Integer.parseInt(portString);
-		} catch (RuntimeException e) {
+		} catch (RuntimeException ignore) {
 			throw new IllegalArgumentException(String.format("Unparseable port number: %s", hostPortString));
 		}
 

src/main/java/org/springframework/data/redis/connection/convert/Converters.java

@@ -109,8 +109,8 @@ public static Properties toProperties(String source) {
 
 		try (StringReader stringReader = new StringReader(source)) {
 			info.load(stringReader);
-		} catch (Exception cause) {
-			throw new RedisSystemException("Cannot read Redis info", cause);
+		} catch (Exception ex) {
+			throw new RedisSystemException("Cannot read Redis info", ex);
 		}
 
 		return info;

src/main/java/org/springframework/data/redis/connection/jedis/JedisClusterConnection.java

@@ -123,8 +123,8 @@ public JedisClusterConnection(JedisCluster cluster) {
 			Object custerCommandExecutor = executorDfa.getPropertyValue("executor");
 			DirectFieldAccessor dfa = new DirectFieldAccessor(custerCommandExecutor);
 			clusterCommandExecutor.setMaxRedirects((Integer) dfa.getPropertyValue("maxRedirects"));
-		} catch (Exception e) {
-			// ignore it and work with the executor default
+		} catch (Exception ignore) {
+			// ignore and work with the executor default
 		}
 	}
 
@@ -381,8 +381,8 @@ public void subscribe(MessageListener listener, byte[]... channels) {
 			JedisMessageListener jedisPubSub = new JedisMessageListener(listener);
 			subscription = new JedisSubscription(listener, jedisPubSub, channels, null);
 			cluster.subscribe(jedisPubSub, channels);
-		} catch (Exception cause) {
-			throw convertJedisAccessException(cause);
+		} catch (Exception ex) {
+			throw convertJedisAccessException(ex);
 		}
 	}
 
@@ -398,8 +398,8 @@ public void pSubscribe(MessageListener listener, byte[]... patterns) {
 			JedisMessageListener jedisPubSub = new JedisMessageListener(listener);
 			subscription = new JedisSubscription(listener, jedisPubSub, null, patterns);
 			cluster.psubscribe(jedisPubSub, patterns);
-		} catch (Exception cause) {
-			throw convertJedisAccessException(cause);
+		} catch (Exception ex) {
+			throw convertJedisAccessException(ex);
 		}
 	}
 
@@ -643,8 +643,8 @@ public void close() throws DataAccessException {
 		if (!closed && disposeClusterCommandExecutorOnClose) {
 			try {
 				clusterCommandExecutor.destroy();
-			} catch (Exception cause) {
-				log.warn("Cannot properly close cluster command executor", cause);
+			} catch (Exception ex) {
+				log.warn("Cannot properly close cluster command executor", ex);
 			}
 		}
 
@@ -864,8 +864,8 @@ public ClusterTopology getTopology() {
 
 					return cached;
 
-				} catch (Exception cause) {
-					errors.put(entry.getKey(), cause);
+				} catch (Exception ex) {
+					errors.put(entry.getKey(), ex);
 				}
 			}
 

src/main/java/org/springframework/data/redis/connection/jedis/JedisConnection.java

@@ -193,9 +193,9 @@ protected JedisConnection(Jedis jedis, @Nullable Pool<Jedis> pool, JedisClientCo
 		if (nodeConfig.getDatabase() != jedis.getDB()) {
 			try {
 				select(nodeConfig.getDatabase());
-			} catch (DataAccessException cause) {
+			} catch (DataAccessException ex) {
 				close();
-				throw cause;
+				throw ex;
 			}
 		}
 	}
@@ -413,17 +413,17 @@ private List<Object> convertPipelineResults() {
 				if (!result.isStatus()) {
 					results.add(result.conversionRequired() ? result.convert(data) : data);
 				}
-			} catch (JedisDataException e) {
-				DataAccessException dataAccessException = convertJedisAccessException(e);
+			} catch (JedisDataException ex) {
+				DataAccessException dataAccessException = convertJedisAccessException(ex);
 				if (cause == null) {
 					cause = dataAccessException;
 				}
 				results.add(dataAccessException);
-			} catch (DataAccessException e) {
+			} catch (DataAccessException ex) {
 				if (cause == null) {
-					cause = e;
+					cause = ex;
 				}
-				results.add(e);
+				results.add(ex);
 			}
 		}
 
@@ -488,8 +488,8 @@ public List<Object> exec() {
 					? new TransactionResultConverter<>(txResults, JedisExceptionConverter.INSTANCE).convert(results)
 					: results;
 
-		} catch (Exception cause) {
-			throw convertJedisAccessException(cause);
+		} catch (Exception ex) {
+			throw convertJedisAccessException(ex);
 		} finally {
 			txResults.clear();
 			transaction = null;
@@ -684,7 +684,7 @@ protected boolean isActive(RedisNode node) {
 			verification = getJedis(node);
 			verification.connect();
 			return verification.ping().equalsIgnoreCase("pong");
-		} catch (Exception cause) {
+		} catch (Exception ignore) {
 			return false;
 		} finally {
 			if (verification != null) {
@@ -708,17 +708,17 @@ private <T> T doWithJedis(Function<Jedis, T> callback) {
 
 		try {
 			return callback.apply(getJedis());
-		} catch (Exception cause) {
-			throw convertJedisAccessException(cause);
+		} catch (Exception ex) {
+			throw convertJedisAccessException(ex);
 		}
 	}
 
 	private void doWithJedis(Consumer<Jedis> callback) {
 
 		try {
 			callback.accept(getJedis());
-		} catch (Exception cause) {
-			throw convertJedisAccessException(cause);
+		} catch (Exception ex) {
+			throw convertJedisAccessException(ex);
 		}
 	}
 
@@ -727,9 +727,9 @@ private void doExceptionThrowingOperationSafely(ExceptionThrowingOperation opera
 		try {
 			operation.run();
 		}
-		catch (Exception cause) {
+		catch (Exception ex) {
 			if (LOGGER.isDebugEnabled()) {
-				LOGGER.debug(logMessage, cause);
+				LOGGER.debug(logMessage, ex);
 			}
 		}
 	}

src/main/java/org/springframework/data/redis/connection/jedis/JedisConnectionFactory.java

@@ -703,8 +703,8 @@ public void stop() {
 				try {
 					clusterCommandExecutor.destroy();
 					this.clusterCommandExecutor = null;
-				} catch (Exception cause) {
-					throw new RuntimeException(cause);
+				} catch (Exception ex) {
+					throw new RuntimeException(ex);
 				}
 			}
 
@@ -715,8 +715,8 @@ public void stop() {
 				try {
 					this.cluster.close();
 					this.cluster = null;
-				} catch (Exception cause) {
-					log.warn("Cannot properly close Jedis cluster", cause);
+				} catch (Exception ex) {
+					log.warn("Cannot properly close Jedis cluster", ex);
 				}
 			}
 
@@ -869,8 +869,8 @@ protected Jedis fetchJedisConnector() {
 			jedis.connect();
 
 			return jedis;
-		} catch (Exception cause) {
-			throw new RedisConnectionFailureException("Cannot get Jedis connection", cause);
+		} catch (Exception ex) {
+			throw new RedisConnectionFailureException("Cannot get Jedis connection", ex);
 		}
 	}
 

src/main/java/org/springframework/data/redis/connection/lettuce/LettuceClusterConnection.java

@@ -382,8 +382,8 @@ public Long clusterCountKeysInSlot(int slot) {
 
 		try {
 			return getConnection().clusterCountKeysInSlot(slot);
-		} catch (Exception cause) {
-			throw this.exceptionConverter.translate(cause);
+		} catch (Exception ex) {
+			throw this.exceptionConverter.translate(ex);
 		}
 	}
 
@@ -453,8 +453,8 @@ public List<byte[]> clusterGetKeysInSlot(int slot, Integer count) {
 
 		try {
 			return getConnection().clusterGetKeysInSlot(slot, count);
-		} catch (Exception cause) {
-			throw this.exceptionConverter.translate(cause);
+		} catch (Exception ex) {
+			throw this.exceptionConverter.translate(ex);
 		}
 	}