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

@@ -307,8 +307,9 @@ private void checkAndPotentiallyWaitUntilUnlocked(String name, RedisConnection c
 			// 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),
-					ex);
+			String message = String.format("Interrupted while waiting to unlock cache %s", name);
+
+			throw new PessimisticLockingFailureException(message, ex);
 		} finally {
 			statistics.incLockTime(name, System.nanoTime() - lockWaitTimeNs);
 		}

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

@@ -152,8 +152,8 @@ 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);
@@ -327,14 +327,14 @@ 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/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);
 			}
 		}
 

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

@@ -405,17 +405,17 @@ 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);
 			}
 		}
 		if (cause != null) {
@@ -670,7 +670,7 @@ protected boolean isActive(RedisNode node) {
 			verification = getJedis(node);
 			verification.connect();
 			return verification.ping().equalsIgnoreCase("pong");
-		} catch (Exception e) {
+		} catch (Exception ignore) {
 			return false;
 		} finally {
 			if (verification != null) {

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

@@ -380,8 +380,8 @@ 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);
 		}
 	}
 
@@ -451,8 +451,8 @@ 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);
 		}
 	}
 

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

@@ -366,8 +366,8 @@ public void close() {
 
 		try {
 			reset();
-		} catch (RuntimeException e) {
-			LOGGER.debug("Failed to reset connection during close", e);
+		} catch (RuntimeException ex) {
+			LOGGER.debug("Failed to reset connection during close", ex);
 		}
 	}
 
@@ -468,11 +468,11 @@ public List<Object> closePipeline() {
 
 						try {
 							results.add(result.conversionRequired() ? result.convert(result.get()) : result.get());
-						} catch (DataAccessException e) {
+						} catch (DataAccessException ex) {
 							if (problem == null) {
-								problem = e;
+								problem = ex;
 							}
-							results.add(e);
+							results.add(ex);
 						}
 					}
 				}
@@ -488,8 +488,8 @@ public List<Object> closePipeline() {
 			}
 
 			throw new RedisPipelineException(new QueryTimeoutException("Redis command timed out"));
-		} catch (Exception e) {
-			throw new RedisPipelineException(e);
+		} catch (Exception ex) {
+			throw new RedisPipelineException(ex);
 		}
 	}
 
@@ -573,7 +573,7 @@ public void select(int dbIndex) {
 
 		if (asyncSharedConn != null) {
 			throw new InvalidDataAccessApiUsageException("Selecting a new database not supported due to shared connection;"
-					+ " Use separate ConnectionFactorys to work with multiple databases");
+					+ " Use separate ConnectionFactory instances to work with multiple databases");
 		}
 
 		this.dbIndex = dbIndex;
@@ -930,7 +930,7 @@ protected boolean isActive(RedisNode node) {
 		try {
 			connection = getConnection(node);
 			return connection.sync().ping().equalsIgnoreCase("pong");
-		} catch (Exception e) {
+		} catch (Exception ignore) {
 			return false;
 		} finally {
 			if (connection != null) {
@@ -965,8 +965,8 @@ private <T> T await(RedisFuture<T> cmd) {
 
 		try {
 			return LettuceFutures.awaitOrCancel(cmd, timeout, TimeUnit.MILLISECONDS);
-		} catch (RuntimeException e) {
-			throw convertLettuceAccessException(e);
+		} catch (RuntimeException ex) {
+			throw convertLettuceAccessException(ex);
 		}
 	}
 
@@ -1031,8 +1031,9 @@ private void validateCommand(ProtocolKeyword cmd, @Nullable byte[]... args) {
 		if (!RedisCommand.UNKNOWN.equals(redisCommand) && redisCommand.requiresArguments()) {
 			try {
 				redisCommand.validateArgumentCount(args != null ? args.length : 0);
-			} catch (IllegalArgumentException e) {
-				throw new InvalidDataAccessApiUsageException(String.format("Validation failed for %s command", cmd), e);
+			} catch (IllegalArgumentException ex) {
+				String message = String.format("Validation failed for %s command", command);
+				throw new InvalidDataAccessApiUsageException(message, ex);
 			}
 		}
 	}
@@ -1041,7 +1042,7 @@ private static ProtocolKeyword getCommandType(String name) {
 
 		try {
 			return CommandType.valueOf(name);
-		} catch (IllegalArgumentException e) {
+		} catch (IllegalArgumentException ignore) {
 			return new CustomCommandType(name);
 		}
 	}

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

@@ -1380,8 +1380,8 @@ void validateConnection() {
 							((StatefulRedisClusterConnection) connection).sync().ping();
 						}
 						valid = true;
-					} catch (Exception e) {
-						log.debug("Validation failed", e);
+					} catch (Exception ex) {
+						log.debug("Validation failed", ex);
 					}
 				}
 
@@ -1531,8 +1531,8 @@ public ExceptionTranslatingConnectionProvider(LettuceConnectionProvider delegate
 
 			try {
 				return delegate.getConnection(connectionType);
-			} catch (RuntimeException e) {
-				throw translateException(e);
+			} catch (RuntimeException ex) {
+				throw translateException(ex);
 			}
 		}
 
@@ -1541,8 +1541,8 @@ public ExceptionTranslatingConnectionProvider(LettuceConnectionProvider delegate
 
 			try {
 				return ((TargetAware) delegate).getConnection(connectionType, redisURI);
-			} catch (RuntimeException e) {
-				throw translateException(e);
+			} catch (RuntimeException ex) {
+				throw translateException(ex);
 			}
 		}