@Test
public void join() {
assertEquals("foo,bar,baz", StringHelper.join(",", new String[] {"foo", "bar", "baz"}));
assertEquals("foobarbaz", StringHelper.join(null, new String[] {"foo", "bar", "baz"}));
// TODO: is this the intended behavior?
assertEquals("foo,,bar", StringHelper.join(",", new String[] {"foo", null, "bar"}));
assertNull(StringHelper.join(null, null));
}
public static List<String> listDatabases(Params params) {
DataSource datasource = createDataSource(params, params.basedb);
JdbcTemplate jdbc = new JdbcTemplate(datasource);
RowMapper<String> mapper =
new RowMapper<String>() {
public String mapRow(ResultSet rs, int rowNum) throws SQLException {
return rs.getString("datname");
}
};
List<String> databases = jdbc.query("select datname from pg_catalog.pg_database", mapper);
System.out.println("databases: " + StringHelper.join(databases, ", "));
return databases;
}
// some or all may be empty
// remove empty ones, surround the rest with parentheses, and join with " AND "
public static String joinSubqueries(String... subqueries) {
List<String> items = StringHelper.clean(subqueries);
items = StringHelper.wrap(items, "(", ")");
return StringHelper.join(items, " AND ");
}