Part part = new Part ( "ชิ้นส่วนตัวอย่าง" , 123.45 );

ส่วนb = parts.stream () . filter ( p - > "gearbox" .equals ( p.getName ( ) ) ) . findFirst ( ) . orElse ( null );

แพ็คเกจorg.wikipedia.examples ;import java.sql.Connection ; import java.sql.DriverManager ; import java.sql.PreparedStatement ; import java.sql.ResultSet ; import java.sql.SQLException ; import java.sql.Statement ;คลาสสาธารณะUser { ตัวแปรint id ; ตัวแปรstring name ; ตัวแปรstring email ;public User ( String name , String email ) { this . name = name ; this . email = email ; }public int getId () { return id ; }public void setId ( int id ) { this.id = id ; }​​public String getName () { return name ; }public void setName ( String name ) { this.name = name ; }​​public String getEmail () { return email ; }public void setEmail ( String email ) { this.email = email ; }​​public void save ( ) { try ( Connection conn = DriverManager.getConnection ( " jdbc : mysql ://localhost:3306/mydb" , " user " , " password " ) ) { if ( this.id == 0 ) { String sql = " INSERT INTO users ( name, email) VALUES (?, ? ) " ; try ( PreparedStatement stmt = conn.prepareStatement ( sql , Statement.RETURN_GENERATED_KEYS ) ) { stmt.setString ( 1 , this.name ) ; stmt.setString ( 2 , this.email ) ; stmt.executeUpdate ( ) ; ResultSet rs = stmt.getGeneratedKeys ( ) ; if ( rs.next ( ) ) { this.id = rs.getInt ( 1 ) ; } } } else { String sql = "UPDATE users SET name = ?, email = ? WHERE id = ?" ; try ( PreparedStatement stmt = conn . prepareStatement ( sql )) { stmt . setString ( 1 , this . name ); stmt . setString ( 2 , this . email ); stmt . setInt ( 3 , this . id ); stmt . executeUpdate (); } } } catch ( SQLException e ) { System . err . printf ( "A SQLException occurred: %s%n" , e .getMessage ()); e.printStackTrace ( ) ; } }public static User find ( int id ) { try ( Connection conn = DriverManager . getConnection ( "jdbc:mysql://localhost:3306/mydb" , "user" , "password" )) { String sql = "SELECT * FROM users WHERE id = ?" ; try ( PreparedStatement stmt = conn . prepareStatement ( sql )) { stmt . setInt ( 1 , id ); ResultSet rs = stmt . executeQuery (); if ( rs . next ()) { User user = new User ( rs . getString ( "name" ), rs . getString ( "email" )); user . setId ( rs . getInt ( "id" )); return user ; } } } catch ( SQLException e ) { System . err . printf ( "เกิด SQLException: %s%n" , e.getMessage ( ) ); e.printStackTrace ( ) ; } return null ; }public void delete ( ) { try ( Connection conn = DriverManager.getConnection ( "jdbc:mysql://localhost:3306/mydb" , " user " , " password " )) { String sql = "DELETE FROM users WHERE id = ?" ; try ( PreparedStatement stmt = conn.prepareStatement ( sql ) ) { stmt.setInt ( 1 , this.id ) ; stmt.executeUpdate ( ); } } catch ( SQLException e ) { System.err.printf ( " A SQLException occurred: % s % n " , e.getMessage ( ) ) ; e.printStackTrace ( ) ; } } }