use StringBuilder for complex string concatenation

spring-beans/src/main/java/org/springframework/beans/AbstractNestablePropertyAccessor.java

@@ -634,7 +634,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 										"property path '" + propertyName + "': returned null");
 					}
 				}
-				String indexedPropertyName = tokens.actualName;
+				StringBuilder indexedPropertyName = new StringBuilder(tokens.actualName);
 				// apply indexes and map keys
 				for (int i = 0; i < tokens.keys.length; i++) {
 					String key = tokens.keys[i];
@@ -645,13 +645,13 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 					}
 					else if (value.getClass().isArray()) {
 						int index = Integer.parseInt(key);
-						value = growArrayIfNecessary(value, index, indexedPropertyName);
+						value = growArrayIfNecessary(value, index, indexedPropertyName.toString());
 						value = Array.get(value, index);
 					}
 					else if (value instanceof List) {
 						int index = Integer.parseInt(key);
 						List<Object> list = (List<Object>) value;
-						growCollectionIfNecessary(list, index, indexedPropertyName, ph, i + 1);
+						growCollectionIfNecessary(list, index, indexedPropertyName.toString(), ph, i + 1);
 						value = list.get(index);
 					}
 					else if (value instanceof Set) {
@@ -686,7 +686,7 @@ public abstract class AbstractNestablePropertyAccessor extends AbstractPropertyA
 								"Property referenced in indexed property path '" + propertyName +
 										"' is neither an array nor a List nor a Set nor a Map; returned value was [" + value + "]");
 					}
-					indexedPropertyName += PROPERTY_KEY_PREFIX + key + PROPERTY_KEY_SUFFIX;
+					indexedPropertyName.append(PROPERTY_KEY_PREFIX).append(key).append(PROPERTY_KEY_SUFFIX);
 				}
 			}
 			return value;

spring-jdbc/src/main/java/org/springframework/jdbc/core/metadata/CallMetaDataContext.java

@@ -618,7 +618,7 @@ public class CallMetaDataContext {
 	public String createCallString() {
 		Assert.state(this.metaDataProvider != null, "No CallMetaDataProvider available");
 
-		String callString;
+		StringBuilder callString;
 		int parameterCount = 0;
 		String catalogNameToUse;
 		String schemaNameToUse;
@@ -637,33 +637,33 @@ public class CallMetaDataContext {
 
 		String procedureNameToUse = this.metaDataProvider.procedureNameToUse(getProcedureName());
 		if (isFunction() || isReturnValueRequired()) {
-			callString = "{? = call " +
-					(StringUtils.hasLength(catalogNameToUse) ? catalogNameToUse + "." : "") +
-					(StringUtils.hasLength(schemaNameToUse) ? schemaNameToUse + "." : "") +
-					procedureNameToUse + "(";
+			callString = new StringBuilder().append("{? = call ").
+					append(StringUtils.hasLength(catalogNameToUse) ? catalogNameToUse + "." : "").
+					append(StringUtils.hasLength(schemaNameToUse) ? schemaNameToUse + "." : "").
+					append(procedureNameToUse).append("(");
 			parameterCount = -1;
 		}
 		else {
-			callString = "{call " +
-					(StringUtils.hasLength(catalogNameToUse) ? catalogNameToUse + "." : "") +
-					(StringUtils.hasLength(schemaNameToUse) ? schemaNameToUse + "." : "") +
-					procedureNameToUse + "(";
+			callString = new StringBuilder().append("{call ").
+					append(StringUtils.hasLength(catalogNameToUse) ? catalogNameToUse + "." : "").
+					append(StringUtils.hasLength(schemaNameToUse) ? schemaNameToUse + "." : "").
+					append(procedureNameToUse).append("(");
 		}
 
 		for (SqlParameter parameter : this.callParameters) {
 			if (!(parameter.isResultsParameter())) {
 				if (parameterCount > 0) {
-					callString += ", ";
+					callString.append(", ");
 				}
 				if (parameterCount >= 0) {
-					callString += createParameterBinding(parameter);
+					callString.append(createParameterBinding(parameter));
 				}
 				parameterCount++;
 			}
 		}
-		callString += ")}";
+		callString.append(")}");
 
-		return callString;
+		return callString.toString();
 	}
 
 	/**