@Override
public String remove(String key) throws IllegalArgumentException {
if (key == null || key.isEmpty() || key.contains("\n") || key.trim().isEmpty()) {
throw new IllegalArgumentException(table.getTableName() + ": remove: key is null");
}
String result;
try {
result = table.remove(key);
} catch (InvalidWorkingException e) {
throw new IllegalArgumentException(e.getMessage());
}
if (values.containsKey(key)) {
changes.put(key, null);
} else {
changes.remove(key);
}
return result;
}
public void rollChanges() {
String oldValue;
String newValue;
for (String key : changes.keySet()) {
oldValue = values.get(key);
newValue = changes.get(key);
if (oldValue != null && !oldValue.equals(newValue)) {
try {
table.put(key, oldValue);
} catch (InvalidWorkingException e) {
System.err.println(
"Can not roll back key = \'" + key + "\' and value = \'" + newValue + "\'");
}
} else if (oldValue == null && newValue != null) {
try {
table.remove(key);
} catch (InvalidWorkingException e) {
System.err.println(
"Can not roll back deleting key = \'" + key + "\' and value = \'" + oldValue + "\'");
}
}
}
}
