Overriding BeanPropertyRowMapper to Support JodaTime DateTime
My Domain object has couple of Joda-Time DateTime
fields. When I'm reading database values using SimpleJdbcTemplate:
Patient patient = jdbc.queryForObject(sql, new BeanPropertyRo开发者_如何学JAVAwMapper(Patient.class), patientId);
It just fails and surprisingly, no errors were logged. I guess it's because of the timestamp
parsing to DateTime
is not working with Jdbc.
If it's possible to inherit and override BeanPropertyRowMapper
and instruct to convert all java.sql.Timestamp
and java.sql.Date
to DateTime
, it would be great and could save a lot of extra code.
Any advice?
The correct thing to do is to subclass BeanPropertyRowMapper
, override initBeanWrapper(BeanWrapper)
and register a custom Property Editor:
public class JodaDateTimeEditor extends PropertyEditorSupport {
@Override
public void setAsText(final String text) throws IllegalArgumentException {
setValue(new DateTime(text)); // date time in ISO8601 format
// (yyyy-MM-ddTHH:mm:ss.SSSZZ)
}
@Override
public void setValue(final Object value) {
super.setValue(value == null || value instanceof DateTime ? value
: new DateTime(value));
}
@Override
public DateTime getValue() {
return (DateTime) super.getValue();
}
@Override
public String getAsText() {
return getValue().toString(); // date time in ISO8601 format
// (yyyy-MM-ddTHH:mm:ss.SSSZZ)
}
}
public class JodaTimeSavvyBeanPropertyRowMapper<T>
extends BeanPropertyRowMapper<T> {
@Override
protected void initBeanWrapper(BeanWrapper bw) {
bw.registerCustomEditor(DateTime.class, new JodaDateTimeEditor());
}
}
Looking at BeanPropertyRowMapper
implementation, the way it sets the fields is:
Object value = getColumnValue( rs, index, pd );
if (logger.isDebugEnabled() && rowNumber == 0) {
logger.debug("Mapping column '" + column + "' to property '" +
pd.getName() + "' of type " + pd.getPropertyType());
}
try {
bw.setPropertyValue(pd.getName(), value);
}
where getColumnValue(rs, index, pd);
delegates to JdbcUtils.getResultSetValue
That pd
field in getColumnValue
is the actual "p roperty d escriptor", that is used ( pd.getPropertyType()
) in JdbcUtils
as a type of the field to map to.
If you look at JdbcUtils
code for getResultSetValue
method, you'll see that it simply goes from one if
statement to another, to match pd.getPropertyType()
to all standard types. When it does not find one, since DateTime
is not a "standard" type, it relies on a rs.getObject()
:
} else {
// Some unknown type desired -> rely on getObject.
Then if this object is a SQL Date it converts it to a Timestamp
, and returns to be set to a DateTime
field of your domain => where it fails.
Hence, there does not seem to be a straight forward way to inject a Date
/Timestamp
to DateTime
converter into a BeanPropertyRowMapper
. So it would be cleaner (and more performant) to implement your own RowMapper.
In case you'd like to see the mapping error in a console, set your logging level for org.springframework.jdbc
to "debug" or better yet "trace" to see exactly what happens.
One thing you can try, which I have not tested, is to extend a BeanPropertyRowMapper
and override a property of DateTime
type in:
/**
* Initialize the given BeanWrapper to be used for row mapping.
* To be called for each row.
* <p>The default implementation is empty. Can be overridden in subclasses.
* @param bw the BeanWrapper to initialize
*/
protected void initBeanWrapper(BeanWrapper bw) {}
The answer of @Sean Patrick Floyd is perfect until you do not have many many custom types.
Here it a generalized, configurable based on usage extension:
public class CustomFieldTypeSupportBeanPropertyRowMapper<T> extends BeanPropertyRowMapper<T> {
private Map<Class<?>, Handler> customTypeMappers = new HashMap<Class<?>, Handler>();
public CustomFieldTypeSupportBeanPropertyRowMapper() {
super();
}
public CustomFieldTypeSupportBeanPropertyRowMapper(Class<T> mappedClass, boolean checkFullyPopulated) {
super(mappedClass, checkFullyPopulated);
}
public CustomFieldTypeSupportBeanPropertyRowMapper(Class<T> mappedClass) {
super(mappedClass);
}
public CustomFieldTypeSupportBeanPropertyRowMapper(Class<T> mappedClass, Map<Class<?>, Handler> customTypeMappers) {
super(mappedClass);
this.customTypeMappers = customTypeMappers;
}
@Override
protected Object getColumnValue(ResultSet rs, int index, PropertyDescriptor pd) throws SQLException {
final Class<?> current = pd.getPropertyType();
if (customTypeMappers.containsKey(current)) {
return customTypeMappers.get(current).f(rs, index, pd);
}
return super.getColumnValue(rs, index, pd);
}
public void addTypeHandler(Class<?> class1, Handler handler2) {
customTypeMappers.put(class1, handler2);
}
public static interface Handler {
public Object f(ResultSet rs, int index, PropertyDescriptor pd) throws SQLException;
}
}
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