Java Reference
In-Depth Information
public Connection getConnection() throws SQLException {
return DriverManager.getConnection(
"jdbc:h2:mem:shakespeare;INIT=CREATE SCHEMA IF NOT EXISTS " + SCHEMA
+ "\\; SET SCHEMA " + SCHEMA + ";DB_CLOSE_DELAY=-1", "sa", ""
);
}
public void initializeDb() throws SQLException {
try (Connection c = getConnection()) {
try (Statement stmt = c.createStatement()) {
BiFunction<SQLException, String, SQLException> exec = (ex, s) -> {
// If there is an exception, return it (punt)
if (ex != null) return ex;
// Execute this command
try {
stmt.execute(s);
return null;
} catch (SQLException e) {
return e;
}
};
// How to manage multiple exceptions
BinaryOperator<SQLException> pickNonnull = (e1, e2) -> {
if (e1 == null) return e2;
if (e2 == null) return e1;
e1.addSuppressed(e2);
return e1;
};
// Execute the statements
SQLException e = Arrays.asList(
"DROP SCHEMA " + SCHEMA,
"CREATE SCHEMA " + SCHEMA,
"SET SCHEMA " + SCHEMA,
"CREATE TABLE \"text\" " +
" (id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR UNIQUE, " +
" year INT)",
"CREATE TABLE line " +
"(id INT PRIMARY KEY AUTO_INCREMENT, text_id INT, " +
" \"offset\" INT)",
"CREATE TABLE word " +
"(id INT PRIMARY KEY AUTO_INCREMENT, " +
" \"value\" VARCHAR UNIQUE)",
"CREATE TABLE line_word " +
" (id INT PRIMARY KEY AUTO_INCREMENT, line_id INT, " +
" word_id INT, \"offset\" INT)"
).stream().reduce(null, exec, pickNonnull);
