conn.setAutoCommit(false); try // multiple operations conn.commit(); catch (SQLException e) conn.rollback(); finally conn.setAutoCommit(true);
A type 4 JDBC driver that allows Java applications to connect to a PostgreSQL database using standard JDBC APIs. It translates JDBC calls into PostgreSQL's wire protocol (libpq). postgres jdbc driver
pstmt.setObject(1, UUID.randomUUID()); UUID id = rs.getObject("id", UUID.class); 5.1 HikariCP (Best Performance) <dependency> <groupId>com.zaxxer</groupId> <artifactId>HikariCP</artifactId> <version>5.1.0</version> </dependency> HikariConfig config = new HikariConfig(); config.setJdbcUrl("jdbc:postgresql://localhost/mydb"); config.setUsername("user"); config.setPassword("pass"); config.setMaximumPoolSize(10); config.setMinimumIdle(5); config.setConnectionTimeout(30000); config.setIdleTimeout(600000); config.setPoolName("PostgresPool"); HikariDataSource dataSource = new HikariDataSource(config); try // multiple operations conn.commit()
pstmt.setFetchSize(1000); // avoids memory overflow ✅ in development ✅ Close ResultSet , Statement , Connection (try-with-resources handles) ✅ Use currentSchema to avoid schema qualification ✅ Monitor with pg_stat_activity ✅ Set ApplicationName for debugging 8.3 Debugging Connection Issues // Enable driver logging java.util.logging.Logger.getLogger("org.postgresql").setLevel(Level.FINE); // Or JVM args -Dorg.postgresql.forceLogger=java.util.logging -Djava.util.logging.config.file=logging.properties 8.4 Connection Validation // Check if connection is alive if (!conn.isValid(5)) // timeout 5 seconds conn = dataSource.getConnection(); // reconnect catch (SQLException e) conn.rollback()
Class.forName("org.postgresql.Driver"); // not required in modern Java
String insert = "INSERT INTO users (name, email) VALUES (?, ?)"; try (PreparedStatement pstmt = conn.prepareStatement(insert, Statement.RETURN_GENERATED_KEYS)) pstmt.setString(1, "John"); pstmt.setString(2, "john@example.com"); pstmt.executeUpdate(); ResultSet keys = pstmt.getGeneratedKeys(); if (keys.next()) long id = keys.getLong(1);
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