org.springframework.data.cassandra.core.cql.converter

Class AbstractResultSetConverter<T>

java.lang.Object

org.springframework.data.cassandra.core.cql.converter.AbstractResultSetConverter<T>

Type Parameters:

T -

All Implemented Interfaces:

Converter<com.datastax.oss.driver.api.core.cql.ResultSet,T>

Direct Known Subclasses:

AbstractResultSetToBasicFixedTypeConverter, ResultSetToByteBufferConverter, ResultSetToListOfStringConverter, ResultSetToStringConverter

public abstract class AbstractResultSetConverter<T>
extends Object
implements Converter<com.datastax.oss.driver.api.core.cql.ResultSet,T>

Convenient converter that can be used to convert a single-row-single-column, single-row-multi-column, or multi-row ResultSet into the a value of a given type. The majority of the expected usage is to convert a single-row-single-column result set into the target type.

The algorithm is:

• if there is one row with one column, convert that value to this converter's type if possible or throw,
• else if there is one row with multiple columns, convert the columns into this converter's type if possible or throw,
• else convert the rows into this converter's type (since there are multiple rows) or throw.

If the converter throws due to the inability to convert a given ResultSet, it will throw an IllegalArgumentException.

Author:

Matthew T. Adams, Mark Paluch

Constructor Summary

Constructors

Constructor and Description
AbstractResultSetConverter()

Method Summary

Modifier and Type	Method and Description
T	convert(com.datastax.oss.driver.api.core.cql.ResultSet source)
protected T	doConvertResultSet(List<Map<String,Object>> resultSet) Converts the given result set (as a List<Map<String,Object>>) to this converter's type or throws IllegalArgumentException.
protected T	doConvertSingleRow(Map<String,Object> row) Converts the given row (as a Map<String,Object>) to this converter's type or throws IllegalArgumentException.
protected abstract T	doConvertSingleValue(Object object) Converts the given value to this converter's type or throws IllegalArgumentException.
protected T	getExhaustedResultSetValue()
protected T	getNullResultSetValue()
protected abstract Class<?>	getType()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.springframework.core.convert.converter.Converter

andThen

Constructor Detail

AbstractResultSetConverter

public AbstractResultSetConverter()

Method Detail

doConvertSingleValue

protected abstract T doConvertSingleValue(Object object)

Converts the given value to this converter's type or throws IllegalArgumentException.

getType

protected abstract Class<?> getType()

Returns:

the target type.

getNullResultSetValue

@Nullable
protected T getNullResultSetValue()

Returns:

surrogate value if the ResultSet is null.

getExhaustedResultSetValue

@Nullable
protected T getExhaustedResultSetValue()

Returns:

surrogate value if the ResultSet is exhausted.

convert

public T convert(com.datastax.oss.driver.api.core.cql.ResultSet source)

Specified by:

convert in interface Converter<com.datastax.oss.driver.api.core.cql.ResultSet,T>

doConvertResultSet

protected T doConvertResultSet(List<Map<String,Object>> resultSet)

Converts the given result set (as a List<Map<String,Object>>) to this converter's type or throws IllegalArgumentException. This default implementation simply throws.

doConvertSingleRow

protected T doConvertSingleRow(Map<String,Object> row)

Converts the given row (as a Map<String,Object>) to this converter's type or throws IllegalArgumentException. This default implementation simply throws.