Sample database connection - WePaHT-SQL/SQLTasker GitHub Wiki
Pom.xml:
4.0.0 wepaht DatabaseTest 1.0-SNAPSHOT jar<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.2.7.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
</dependency>
</dependencies>
Testiluokka:
package wepaht.db;
import java.sql.Connection; import java.sql.DatabaseMetaData; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.Statement; import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication public class Main {
public static void main(String[] args) throws Exception {
// ConfigurableApplicationContext ctx = SpringApplication.run(Main.class, args);
Connection helloConnection = createConnectionToDatabase("hello");
Connection worldConnection = createConnectionToDatabase("world");
System.out.println("Tables in hello");
showTables(helloConnection);
helloConnection.close();
System.out.println("");
System.out.println("Tables in world");
showTables(worldConnection);
// List connections = new ArrayList<>();
//
// while(true) {
// connections.add(createConnectionToDatabase(UUID.randomUUID().toString()));
// }
}
private static void showTables(Connection conn) throws Exception {
DatabaseMetaData md = conn.getMetaData();
ResultSet rs = md.getTables(null, null, "%", null);
while (rs.next()) {
System.out.println(rs.getString(3));
}
Statement stmt = conn.createStatement();
int result = stmt.executeUpdate("CREATE TABLE Foo(id integer)");
System.out.println("Tietokantataulu luotu");
stmt.executeUpdate("INSERT INTO Foo (id) VALUES (3);");
System.out.println("dataa syötetty");
System.out.println("Tässä tulokset:");
rs = stmt.executeQuery("SELECT * FROM Foo");
while (rs.next()) {
System.out.println(rs.getInt("id"));
}
System.out.println("");
}
private static Connection createConnectionToDatabase(String databasename) throws Exception {
Class.forName("org.h2.Driver");
String url = "jdbc:h2:mem:" + databasename;
String user = "sa";
String pwds = "sa";
Connection conn = DriverManager.
getConnection(url, user, pwds);
return conn;
}
}