dmv.spring.demo.model.repository.jdbc

Class JdbcConnector

java.lang.Object

dmv.spring.demo.model.repository.jdbc.JdbcConnector

All Implemented Interfaces:

AutoCloseable

public class JdbcConnector
extends Object
implements AutoCloseable

Custom made manager for Connection and PreparedStatement, to be used in Repository classes. Reducing boilerplate code. The Connection is a pooled Connection from DataSourceUtils class

SQLException will be converted to AccessDataBaseException at this level: opening and closing connections, setting parameters.

It's not thread safe, and is expected to be created and then closed within a single method.

It implements AutoCloseable interface and could be used with try-with-resources statement

Author:

dmv

Constructor Summary

Constructors

Constructor and Description
JdbcConnector(DataSource dataSource, NativeSQLQueries query) Creates Connection and PreparedStatement objects from given dataSource, using provided query.

Method Summary

Modifier and Type	Method and Description
void	close() Close underlying statement and release connection
long	getLong(int resultIndex, int columnIndex) Gets long from resultIndex ResultSet at columnIndex position
<T> T	getObject(int resultIndex, org.springframework.jdbc.core.RowMapper<T> mapper) Retrieves an object from ResultSet found in a list of results at given index, using provided mapper
<T> Set<T>	getObjects(int resultIndex, org.springframework.jdbc.core.RowMapper<T> mapper) Retrieves a set of objects from results list at given index, using provided mapper
List<ResultSet>	getResults() Execute statement and return a list with ResultSet objects
String	getString(int resultIndex, int columnIndex) Gets String from resultIndex ResultSet at columnIndex position
int	getUpdateCount() Returns the first update count after execution.
void	setLong(int pos, long num) Set Long number at specified position
void	setRequiredString(int pos, String field, String fieldName) Set String which is required for current statement at given position.
void	setString(int pos, String field) Set String that can be null or empty to current statement at given position.

Methods inherited from class java.lang.Object

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

Constructor Detail

JdbcConnector

public JdbcConnector(DataSource dataSource,
                     NativeSQLQueries query)

Creates Connection and PreparedStatement objects from given dataSource, using provided query.

Don't forget to call close() method in the end.

Parameters:

dataSource - the DataSource to be used

query - the NativeSQLQueries query

Throws:

AccessDataBaseException - if open connection and prepare statement operations were not successful

Method Detail

close

public void close()

Close underlying statement and release connection

Specified by:

close in interface AutoCloseable

Throws:

AccessDataBaseException - if closing operations were not successful

getUpdateCount

public int getUpdateCount()

Returns the first update count after execution.

This method won't get or cache any results (i.e. Result Sets are not expected). Use getResults() method instead if you need them.

Returns:

the first update count

Throws:

AccessDataBaseException - translates SQLExceptions

See Also:

Statement.getUpdateCount()

getResults

public List<ResultSet> getResults()

Execute statement and return a list with ResultSet objects

Returns:

A list with available results (with RAM) or empty list if there were Update Counts only

Throws:

AccessDataBaseException - translates SQLExceptions

getLong

public long getLong(int resultIndex,
                    int columnIndex)

Gets long from resultIndex ResultSet at columnIndex position

Parameters:

resultIndex - The results list index (java - 0 based)

columnIndex - The column number (sql - 1 based)

Returns:

long result

Throws:

AccessDataBaseException - translates SQLExceptions, and 'out of bound' errors will also fall into this category

getString

public String getString(int resultIndex,
                        int columnIndex)

Gets String from resultIndex ResultSet at columnIndex position

Parameters:

resultIndex - The results list index (java - 0 based)

columnIndex - The column number (sql - 1 based)

Returns:

String result

Throws:

AccessDataBaseException - translates SQLExceptions, and 'out of bound' errors will also fall into this category

getObject

public <T> T getObject(int resultIndex,
                       org.springframework.jdbc.core.RowMapper<T> mapper)

Retrieves an object from ResultSet found in a list of results at given index, using provided mapper

Type Parameters:

T - Entity type is expected (like Role or User)

Parameters:

resultIndex - list index (0 if expecting single result)

mapper - the mapper to be used for objects creation

Returns:

a constructed object or null if none found

Throws:

AccessDataBaseException - translates SQLExceptions, and 'out of bound' errors will also fall into this category

getObjects

public <T> Set<T> getObjects(int resultIndex,
                             org.springframework.jdbc.core.RowMapper<T> mapper)

Retrieves a set of objects from results list at given index, using provided mapper

Type Parameters:

T - Entity type is expected (like Role or User)

Parameters:

resultIndex - list index (0 if expecting single result)

mapper - the mapper to be used for objects creation

Returns:

a set of constructed objects or empty set if none found

Throws:

AccessDataBaseException - translates SQLExceptions, and 'out of bound' errors will also fall into this category

setLong

public void setLong(int pos,
                    long num)

Set Long number at specified position

Parameters:

pos - The position is SQL 1-based index

num - a number to set

Throws:

AccessDataBaseException - translates PreparedStatement.setLong(int, long) exception

setString

public void setString(int pos,
                      String field)

Set String that can be null or empty to current statement at given position.

Parameters:

pos - The position is SQL 1-based index

field - the actual String to be set

Throws:

AccessDataBaseException - translates PreparedStatement.setString(int, String) exception

setRequiredString

public void setRequiredString(int pos,
                              String field,
                              String fieldName)

Set String which is required for current statement at given position.

Parameters:

pos - The position is SQL 1-based index

field - the actual String to be set

fieldName - field name (for logging and error messages)

Throws:

IllegalArgumentException - if field is null or empty string

AccessDataBaseException - translates PreparedStatement.setString(int, String) exception