jdbc

Simple DataSource implementation and DataSource wrapper with log capabilities.

Example of usage

DriverManagerDataSource

DataSource implementation which creates connections using DriverManager class. It makes no pooling. Creates new Connection instance each time when getConnection is called.

It is usefull for testing jdbc code which uses DataSource instance independently of environment which creates such instance.

Example of h2 DataSource instance creation

	DataSource ds = DriverManagerDataSource.instance(
			"org.h2.Driver"
			, "jdbc:h2:./target/databasefilename.h2;MODE=PostgreSQL"
			, "user"
			, "pass"
	);

LogDataSource

Wraps DataSource instance with some log capabilities. It logs

• connection commits/rollbacks
• statement executions
• prepared statement executions with params
• result set counts

Example of wrapping DataSource instance

	ds = LogDataSource.wrap(ds, 
			LogConfig.instance(
					() -> jdbclog.isDebugEnabled()
					, (message) -> jdbclog.debug(message))
		);

LogConfig

This class cumulates configuration of logging.

• Consumer consumer - provides connection to logging real api
• ConsumerStatus consumerStatus - provides connection to logging real api
• boolean logStatement = true - enables loging of statement execution
• boolean logResultSet = true - enables loging of result set counts (on close)
• boolean logTransaction = true - enables loging of transaction boundaries

Log examples

connection boundary with connection identity 10

jdbc [10] commit time: 0

statement with connection identity 10 and statement identity 8

jdbc [10][8] statement: select vs, description from mytable where vs = '1111111111' time: 0

prepared statement with connection identity 10 and statement identity 9

jdbc [10][9] statement: update mytable set vs=?, description=? where vs = '1111111111' params:  ?1:1111111111 ?2:22222  result: 1 time: 1

result set with connection identity 10 and statement identity 8

jdbc [10][8] resultset row count: 2 first row time: 0 all row time: 2 close time: 0

utilities

Db wraps Connection, Statement ResultSet to one holder objects. You don't neet to hold them in separate variables and correctly close them. Db holds last this objects and closses previous if newone is created. And Db.close() closses all currently opend objects in order ResultSet, Statement, PreparedStatement and Connection. (Only one statement and resultset in time is handled by the wrapper)

try (Db db = Db.instance(ds)) {a
    db.executeQuery("select count(*) from ra_county");
    if(db.rs().next()) System.out.println("county count: " + db.rs().getInt(1));
    
    db.executeQuery("select count(*) from ra_street");
    if(db.rs().next()) System.out.println("street count: " + db.rs().getInt(1));
    
    db.prepareStatement("update ra_street set name = ? where is = ?");
    db.ps().setString(1, "new name");
    db.ps().setLong(2, 12321);
    db.executeUpdate();

	db.conn().commit();
} catch(Exception e) {
}

If you have script file and you wants to execute this.

private static String SCHEMA =
    """
    create table ra_region (id bigint primary key, code varchar(50), name varchar(5000));
    create index ra_region ON ra_region (code) ; -- just comment
    
	create table ra_county (id bigint primary key, code varchar(50), name varchar(5000));
    create table ra_street (id bigint primary key, code varchar(50), name varchar(5000));
	"""

   try (Db db = Db.instance(ds)) {
       Script.instance(SCHEMA).execute(db.conn());
       
	   Script.instance(new FileReader("/tmp/init-db.sql"))
                    .commitAfter(100)
                    .execute(db.conn());
   } catch(Exception ee) {
   }

Maven usage

   <dependency>
      <groupId>io.github.antonsjava</groupId>
      <artifactId>jdbc</artifactId>
      <version>LASTVERSION</version>
   </dependency>