Spring JDBC 6.1.4 · org.springframework.jdbc.core.RowCountCallbackHandler

Implementation of RowCallbackHandler. Convenient superclass for callback handlers. An instance can only be used once.

We can either use this on its own (for example, in a test case, to ensure that our result sets have valid dimensions), or use it as a superclass for callback handlers that actually do something, and will benefit from the dimension information it provides.

A usage example with JdbcTemplate:

JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);  // reusable object

RowCountCallbackHandler countCallback = new RowCountCallbackHandler();  // not reusable
jdbcTemplate.query("select * from user", countCallback);
int rowCount = countCallback.getRowCount();

Modifier and Type	Field and Description
private int	columnCount Columns we've seen so far.
private String[]	columnNames Indexed from 0.
private int[]	columnTypes Indexed from 0.
private int	rowCount Rows we've seen so far.

Constructor Summary

Access	Constructor and Description
public	RowCountCallbackHandler()

Method Summary

Modifier and Type	Method and Description
public final int	Returns: the number of columns in this result set getColumnCount() Return the number of columns in this result set.
public final String[]	Returns: the names of the columns. Indexed from 0 to n-1. getColumnNames() Return the names of the columns.
public final int[]	Returns: the types of the columns as java.sql.Types constants. Indexed from 0 to n-1. getColumnTypes() Return the types of the columns as java.sql.Types constants Valid after processRow is invoked the first time.
public final int	Returns: the number of rows in this ResultSet getRowCount() Return the row count of this ResultSet.
public final void	processRow(ResultSet the `ResultSet` to process (pre-initialized for the current row) rs) Implements org.springframework.jdbc.core.RowCallbackHandler.processRow. Implementation of ResultSetCallbackHandler.
protected void	processRow(ResultSet the ResultSet to extract data from. This method is invoked for each row rs, int number of the current row (starting from 0) rowNum) Subclasses may override this to perform custom extraction or processing.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

columnCount	back to summary
private int columnCount Columns we've seen so far.

columnNames	back to summary
private String[] columnNames Indexed from 0. Column name as returned by ResultSetMetaData object. Annotations @Nullable

columnTypes	back to summary
private int[] columnTypes Indexed from 0. Type (as in java.sql.Types) for the columns as returned by ResultSetMetaData object. Annotations @Nullable

rowCount	back to summary
private int rowCount Rows we've seen so far.

Constructor Detail

RowCountCallbackHandler	back to summary
public RowCountCallbackHandler()

Method Detail

getColumnCount	back to summary
public final int getColumnCount() Return the number of columns in this result set. Valid once we've seen the first row, so subclasses can use it during processing Returns:int the number of columns in this result set

getColumnCount

back to summary

public final int getColumnCount()

Return the number of columns in this result set. Valid once we've seen the first row, so subclasses can use it during processing

Returns:int: the number of columns in this result set

getColumnNames	back to summary
public final String[] getColumnNames() Return the names of the columns. Valid after processRow is invoked the first time. Returns:String[] the names of the columns. Indexed from 0 to n-1. Annotations @Nullable

getColumnNames

back to summary

public final String[] getColumnNames()

Return the names of the columns. Valid after processRow is invoked the first time.

Returns:String[]

the names of the columns. Indexed from 0 to n-1.

Annotations

@Nullable

getColumnTypes	back to summary
public final int[] getColumnTypes() Return the types of the columns as java.sql.Types constants Valid after processRow is invoked the first time. Returns:int[] the types of the columns as java.sql.Types constants. Indexed from 0 to n-1. Annotations @Nullable

getColumnTypes

back to summary

public final int[] getColumnTypes()

Return the types of the columns as java.sql.Types constants Valid after processRow is invoked the first time.

Returns:int[]

the types of the columns as java.sql.Types constants. Indexed from 0 to n-1.

Annotations

@Nullable

getRowCount	back to summary
public final int getRowCount() Return the row count of this ResultSet. Only valid after processing is complete Returns:int the number of rows in this ResultSet

getRowCount

back to summary

public final int getRowCount()

Return the row count of this ResultSet. Only valid after processing is complete

Returns:int: the number of rows in this ResultSet

processRow back to summary

processRow	back to summary
public final void processRow(ResultSet rs) throws SQLException Implements org.springframework.jdbc.core.RowCallbackHandler.processRow. Implementation of ResultSetCallbackHandler. Work out column size if this is the first row, otherwise just count rows. Subclasses can perform custom extraction or processing by overriding the `processRow(ResultSet, int)` method. Parameters rs:ResultSet Doc from org.springframework.jdbc.core.RowCallbackHandler.processRow. the `ResultSet` to process (pre-initialized for the current row) Annotations @Override Exceptions SQLException: Doc from org.springframework.jdbc.core.RowCallbackHandler.processRow. if an `SQLException` is encountered getting column values (that is, there's no need to catch `SQLException`) See Also `processRow(java.sql.ResultSet, int)`

public final void processRow(ResultSet rs) throws SQLException

Implements org.springframework.jdbc.core.RowCallbackHandler.processRow.

Implementation of ResultSetCallbackHandler. Work out column size if this is the first row, otherwise just count rows.

Subclasses can perform custom extraction or processing by overriding the processRow(ResultSet, int) method.

Parameters

rs:ResultSet

Doc from org.springframework.jdbc.core.RowCallbackHandler.processRow.

the ResultSet to process (pre-initialized for the current row)

Annotations

@Override

Exceptions

SQLException:

Doc from org.springframework.jdbc.core.RowCallbackHandler.processRow.

if an SQLException is encountered getting column values (that is, there's no need to catch SQLException)

See Also

processRow(java.sql.ResultSet, int)

processRow	back to summary
protected void processRow(ResultSet rs, int rowNum) throws SQLException Subclasses may override this to perform custom extraction or processing. This class's implementation does nothing. Parameters rs:ResultSet the ResultSet to extract data from. This method is invoked for each row rowNum:int number of the current row (starting from 0)

processRow

back to summary

protected void processRow(ResultSet rs, int rowNum) throws SQLException

Subclasses may override this to perform custom extraction or processing. This class's implementation does nothing.

Parameters

rs:ResultSet: the ResultSet to extract data from. This method is invoked for each row
rowNum:int: number of the current row (starting from 0)

public Class RowCountCallbackHandler

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail