java.lang.Object
- org.springframework.dao.support.DataAccessUtils

```
public abstract class DataAccessUtils
extends Object
```
Miscellaneous utility methods for DAO implementations. Useful with any data access technology.
Since:
1.0.2
Author:
Juergen Hoeller

Constructor Summary
Constructors
Constructor Description
DataAccessUtils()

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static int`	`intResult(Collection<?> results)`	Return a unique int result from the given Collection.
`static long`	`longResult(Collection<?> results)`	Return a unique long result from the given Collection.
`static <T> T`	`nullableSingleResult(Collection<T> results)`	Return a single result object from the given Collection.
`static <T> T`	`objectResult(Collection<?> results, Class<T> requiredType)`	Return a unique result object from the given Collection.
`static <T> T`	`requiredSingleResult(Collection<T> results)`	Return a single result object from the given Collection.
`static <T> T`	`requiredUniqueResult(Collection<T> results)`	Return a unique result object from the given Collection.
`static <T> T`	`singleResult(Collection<T> results)`	Return a single result object from the given Collection.
`static RuntimeException`	`translateIfNecessary(RuntimeException rawException, PersistenceExceptionTranslator pet)`	Return a translated exception if this is appropriate, otherwise return the given exception as-is.
`static <T> T`	`uniqueResult(Collection<T> results)`	Return a unique result object from the given Collection.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DataAccessUtils
```
public DataAccessUtils()
```
- Method Detail
  - singleResult
```
@Nullable
public static <T> T singleResult(@Nullable
                                 Collection<T> results)
                          throws IncorrectResultSizeDataAccessException
```
    Return a single result object from the given Collection.
    Returns null if 0 result objects found; throws an exception if more than 1 element found.
    Parameters:
    results - the result Collection (can be null)
    Returns:
    the single result object, or null if none
    Throws:
    IncorrectResultSizeDataAccessException - if more than one element has been found in the given Collection
  - requiredSingleResult
```
public static <T> T requiredSingleResult(@Nullable
                                         Collection<T> results)
                                  throws IncorrectResultSizeDataAccessException
```
    Return a single result object from the given Collection.
    Throws an exception if 0 or more than 1 element found.
    Parameters:
    results - the result Collection (can be null but is not expected to contain null elements)
    Returns:
    the single result object
    Throws:
    IncorrectResultSizeDataAccessException - if more than one element has been found in the given Collection
    EmptyResultDataAccessException - if no element at all has been found in the given Collection
  - nullableSingleResult
```
@Nullable
public static <T> T nullableSingleResult(@Nullable
                                         Collection<T> results)
                                  throws IncorrectResultSizeDataAccessException
```
    Return a single result object from the given Collection.
    Throws an exception if 0 or more than 1 element found.
    Parameters:
    results - the result Collection (can be null and is also expected to contain null elements)
    Returns:
    the single result object
    Throws:
    IncorrectResultSizeDataAccessException - if more than one element has been found in the given Collection
    EmptyResultDataAccessException - if no element at all has been found in the given Collection
    Since:
    5.0.2
  - uniqueResult
```
@Nullable
public static <T> T uniqueResult(@Nullable
                                 Collection<T> results)
                          throws IncorrectResultSizeDataAccessException
```
    Return a unique result object from the given Collection.
    Returns null if 0 result objects found; throws an exception if more than 1 instance found.
    Parameters:
    results - the result Collection (can be null)
    Returns:
    the unique result object, or null if none
    Throws:
    IncorrectResultSizeDataAccessException - if more than one result object has been found in the given Collection
    See Also:
    CollectionUtils.hasUniqueObject(java.util.Collection<?>)
  - requiredUniqueResult
```
public static <T> T requiredUniqueResult(@Nullable
                                         Collection<T> results)
                                  throws IncorrectResultSizeDataAccessException
```
    Return a unique result object from the given Collection.
    Throws an exception if 0 or more than 1 instance found.
    Parameters:
    results - the result Collection (can be null but is not expected to contain null elements)
    Returns:
    the unique result object
    Throws:
    IncorrectResultSizeDataAccessException - if more than one result object has been found in the given Collection
    EmptyResultDataAccessException - if no result object at all has been found in the given Collection
    See Also:
    CollectionUtils.hasUniqueObject(java.util.Collection<?>)
  - objectResult
```
public static <T> T objectResult(@Nullable
                                 Collection<?> results,
                                 @Nullable
                                 Class<T> requiredType)
                          throws IncorrectResultSizeDataAccessException,
                                 TypeMismatchDataAccessException
```
    Return a unique result object from the given Collection. Throws an exception if 0 or more than 1 result objects found, of if the unique result object is not convertible to the specified required type.
    Parameters:
    results - the result Collection (can be null but is not expected to contain null elements)
    Returns:
    the unique result object
    Throws:
    IncorrectResultSizeDataAccessException - if more than one result object has been found in the given Collection
    EmptyResultDataAccessException - if no result object at all has been found in the given Collection
    TypeMismatchDataAccessException - if the unique object does not match the specified required type
  - intResult
```
public static int intResult(@Nullable
                            Collection<?> results)
                     throws IncorrectResultSizeDataAccessException,
                            TypeMismatchDataAccessException
```
    Return a unique int result from the given Collection. Throws an exception if 0 or more than 1 result objects found, of if the unique result object is not convertible to an int.
    Parameters:
    results - the result Collection (can be null but is not expected to contain null elements)
    Returns:
    the unique int result
    Throws:
    IncorrectResultSizeDataAccessException - if more than one result object has been found in the given Collection
    EmptyResultDataAccessException - if no result object at all has been found in the given Collection
    TypeMismatchDataAccessException - if the unique object in the collection is not convertible to an int
  - longResult
```
public static long longResult(@Nullable
                              Collection<?> results)
                       throws IncorrectResultSizeDataAccessException,
                              TypeMismatchDataAccessException
```
    Return a unique long result from the given Collection. Throws an exception if 0 or more than 1 result objects found, of if the unique result object is not convertible to a long.
    Parameters:
    results - the result Collection (can be null but is not expected to contain null elements)
    Returns:
    the unique long result
    Throws:
    IncorrectResultSizeDataAccessException - if more than one result object has been found in the given Collection
    EmptyResultDataAccessException - if no result object at all has been found in the given Collection
    TypeMismatchDataAccessException - if the unique object in the collection is not convertible to a long
  - translateIfNecessary
```
public static RuntimeException translateIfNecessary(RuntimeException rawException,
                                                    PersistenceExceptionTranslator pet)
```
    Return a translated exception if this is appropriate, otherwise return the given exception as-is.
    Parameters:
    rawException - an exception that we may wish to translate
    pet - the PersistenceExceptionTranslator to use to perform the translation
    Returns:
    a translated persistence exception if translation is possible, or the raw exception if it is not

Class DataAccessUtils

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

DataAccessUtils

Method Detail

singleResult

requiredSingleResult

nullableSingleResult

uniqueResult

requiredUniqueResult

objectResult

intResult

longResult

translateIfNecessary