DefaultResultSetHandler#applyColumnOrderBasedConstructorAutomapping() should call Constructor.getParameterTypes() just once #3113
Description
MyBatis version
3.5.14
DefaultResultSetHandler
It's not a bug, but memory resources can be reduced by fixing it i guess
In this code block, constructor.getParameterTypes() method is called so much, which clones objects causing memory waste.
private boolean applyColumnOrderBasedConstructorAutomapping(ResultSetWrapper rsw, List<Class<?>> constructorArgTypes,
List<Object> constructorArgs, Constructor<?> constructor, boolean foundValues) throws SQLException {
for (int i = 0; i < constructor.getParameterTypes().length; i++) {
Class<?> parameterType = constructor.getParameterTypes()[i];
String columnName = rsw.getColumnNames().get(i);
TypeHandler<?> typeHandler = rsw.getTypeHandler(parameterType, columnName);
Object value = typeHandler.getResult(rsw.getResultSet(), columnName);
constructorArgTypes.add(parameterType);
constructorArgs.add(value);
foundValues = value != null || foundValues;
}
return foundValues;
}so i suggest this:
private boolean applyColumnOrderBasedConstructorAutomapping(ResultSetWrapper rsw, List<Class<?>> constructorArgTypes,
List<Object> constructorArgs, Constructor<?> constructor, boolean foundValues) throws SQLException {
Class<?>[] parameterTypes = constructor.getParameterTypes(); // called once at the beginning
for (int i = 0; i < parameterTypes.length; i++) {
Class<?> parameterType = parameterTypes[i];
String columnName = rsw.getColumnNames().get(i);
TypeHandler<?> typeHandler = rsw.getTypeHandler(parameterType, columnName);
Object value = typeHandler.getResult(rsw.getResultSet(), columnName);
constructorArgTypes.add(parameterType);
constructorArgs.add(value);
foundValues = value != null || foundValues;
}
return foundValues;
}