org.springframework.jdbc.support
Class JdbcUtils

java.lang.Object
  extended by org.springframework.jdbc.support.JdbcUtils

public abstract class JdbcUtils
extends java.lang.Object

Generic utility methods for working with JDBC. Mainly for internal use within the framework, but also useful for custom JDBC access code.

Author:
Thomas Risberg, Juergen Hoeller

Field Summary
static int TYPE_UNKNOWN
          Constant that indicates an unknown (or unspecified) SQL type.
 
Constructor Summary
JdbcUtils()
           
 
Method Summary
static void closeConnection(java.sql.Connection con)
          Close the given JDBC Connection and ignore any thrown exception.
static void closeResultSet(java.sql.ResultSet rs)
          Close the given JDBC ResultSet and ignore any thrown exception.
static void closeStatement(java.sql.Statement stmt)
          Close the given JDBC Statement and ignore any thrown exception.
static java.lang.String commonDatabaseName(java.lang.String source)
          Extract a common name for the database in use even if various drivers/platforms provide varying names.
static java.lang.String convertUnderscoreNameToPropertyName(java.lang.String name)
          Convert a column name with underscores to the corresponding property name using "camel case".
static java.lang.Object extractDatabaseMetaData(javax.sql.DataSource dataSource, DatabaseMetaDataCallback action)
          Extract database meta data via the given DatabaseMetaDataCallback.
static java.lang.Object extractDatabaseMetaData(javax.sql.DataSource dataSource, java.lang.String metaDataMethodName)
          Call the specified method on DatabaseMetaData for the given DataSource, and extract the invocation result.
static java.lang.Object getResultSetValue(java.sql.ResultSet rs, int index)
          Retrieve a JDBC column value from a ResultSet, using the most appropriate value type.
static java.lang.Object getResultSetValue(java.sql.ResultSet rs, int index, java.lang.Class requiredType)
          Retrieve a JDBC column value from a ResultSet, using the specified value type.
static boolean isNumeric(int sqlType)
          Check whether the given SQL type is numeric.
static java.lang.String lookupColumnName(java.sql.ResultSetMetaData resultSetMetaData, int columnIndex)
          Determine the column name to use.
static boolean supportsBatchUpdates(java.sql.Connection con)
          Return whether the given JDBC driver supports JDBC 2.0 batch updates.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

TYPE_UNKNOWN

public static final int TYPE_UNKNOWN
Constant that indicates an unknown (or unspecified) SQL type.

See Also:
Types, Constant Field Values
Constructor Detail

JdbcUtils

public JdbcUtils()
Method Detail

closeConnection

public static void closeConnection(java.sql.Connection con)
Close the given JDBC Connection and ignore any thrown exception. This is useful for typical finally blocks in manual JDBC code.

Parameters:
con - the JDBC Connection to close (may be null)

closeStatement

public static void closeStatement(java.sql.Statement stmt)
Close the given JDBC Statement and ignore any thrown exception. This is useful for typical finally blocks in manual JDBC code.

Parameters:
stmt - the JDBC Statement to close (may be null)

closeResultSet

public static void closeResultSet(java.sql.ResultSet rs)
Close the given JDBC ResultSet and ignore any thrown exception. This is useful for typical finally blocks in manual JDBC code.

Parameters:
rs - the JDBC ResultSet to close (may be null)

getResultSetValue

public static java.lang.Object getResultSetValue(java.sql.ResultSet rs,
                                                 int index,
                                                 java.lang.Class requiredType)
                                          throws java.sql.SQLException
Retrieve a JDBC column value from a ResultSet, using the specified value type.

Uses the specifically typed ResultSet accessor methods, falling back to getResultSetValue(java.sql.ResultSet, int) for unknown types.

Note that the returned value may not be assignable to the specified required type, in case of an unknown type. Calling code needs to deal with this case appropriately, e.g. throwing a corresponding exception.

Parameters:
rs - is the ResultSet holding the data
index - is the column index
requiredType - the required value type (may be null)
Returns:
the value object
Throws:
java.sql.SQLException - if thrown by the JDBC API

getResultSetValue

public static java.lang.Object getResultSetValue(java.sql.ResultSet rs,
                                                 int index)
                                          throws java.sql.SQLException
Retrieve a JDBC column value from a ResultSet, using the most appropriate value type. The returned value should be a detached value object, not having any ties to the active ResultSet: in particular, it should not be a Blob or Clob object but rather a byte array respectively String representation.

Uses the getObject(index) method, but includes additional "hacks" to get around Oracle 10g returning a non-standard object for its TIMESTAMP datatype and a java.sql.Date for DATE columns leaving out the time portion: These columns will explicitly be extracted as standard java.sql.Timestamp object.

Parameters:
rs - is the ResultSet holding the data
index - is the column index
Returns:
the value object
Throws:
java.sql.SQLException - if thrown by the JDBC API
See Also:
Blob, Clob, Timestamp

extractDatabaseMetaData

public static java.lang.Object extractDatabaseMetaData(javax.sql.DataSource dataSource,
                                                       DatabaseMetaDataCallback action)
                                                throws MetaDataAccessException
Extract database meta data via the given DatabaseMetaDataCallback.

This method will open a connection to the database and retrieve the database metadata. Since this method is called before the exception translation feature is configured for a datasource, this method can not rely on the SQLException translation functionality.

Any exceptions will be wrapped in a MetaDataAccessException. This is a checked exception and any calling code should catch and handle this exception. You can just log the error and hope for the best, but there is probably a more serious error that will reappear when you try to access the database again.

Parameters:
dataSource - the DataSource to extract metadata for
action - callback that will do the actual work
Returns:
object containing the extracted information, as returned by the DatabaseMetaDataCallback's processMetaData method
Throws:
MetaDataAccessException - if meta data access failed

extractDatabaseMetaData

public static java.lang.Object extractDatabaseMetaData(javax.sql.DataSource dataSource,
                                                       java.lang.String metaDataMethodName)
                                                throws MetaDataAccessException
Call the specified method on DatabaseMetaData for the given DataSource, and extract the invocation result.

Parameters:
dataSource - the DataSource to extract meta data for
metaDataMethodName - the name of the DatabaseMetaData method to call
Returns:
the object returned by the specified DatabaseMetaData method
Throws:
MetaDataAccessException - if we couldn't access the DatabaseMetaData or failed to invoke the specified method
See Also:
DatabaseMetaData

supportsBatchUpdates

public static boolean supportsBatchUpdates(java.sql.Connection con)
Return whether the given JDBC driver supports JDBC 2.0 batch updates.

Typically invoked right before execution of a given set of statements: to decide whether the set of SQL statements should be executed through the JDBC 2.0 batch mechanism or simply in a traditional one-by-one fashion.

Logs a warning if the "supportsBatchUpdates" methods throws an exception and simply returns false in that case.

Parameters:
con - the Connection to check
Returns:
whether JDBC 2.0 batch updates are supported
See Also:
DatabaseMetaData.supportsBatchUpdates()

commonDatabaseName

public static java.lang.String commonDatabaseName(java.lang.String source)
Extract a common name for the database in use even if various drivers/platforms provide varying names.

Parameters:
source - the name as provided in database metedata
Returns:
the common name to be used

isNumeric

public static boolean isNumeric(int sqlType)
Check whether the given SQL type is numeric.

Parameters:
sqlType - the SQL type to be checked
Returns:
whether the type is numeric

lookupColumnName

public static java.lang.String lookupColumnName(java.sql.ResultSetMetaData resultSetMetaData,
                                                int columnIndex)
                                         throws java.sql.SQLException
Determine the column name to use. The column name is determined based on a lookup using ResultSetMetaData.

This method implementation takes into account recent clarifications expressed in the JDBC 4.0 specification:

columnLabel - the label for the column specified with the SQL AS clause. If the SQL AS clause was not specified, then the label is the name of the column.

Parameters:
resultSetMetaData - the current meta data to use
columnIndex - the index of the column for the look up
Returns:
the column name to use
Throws:
java.sql.SQLException - in case of lookup failure

convertUnderscoreNameToPropertyName

public static java.lang.String convertUnderscoreNameToPropertyName(java.lang.String name)
Convert a column name with underscores to the corresponding property name using "camel case". A name like "customer_number" would match a "customerNumber" property name.

Parameters:
name - the column name to be converted
Returns:
the name using "camel case"