Java는 데이터베이스가 존재하는지 확인합니다.

public static boolean isExistDatabase(String database) {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;// 数据库结果集
        try {
            conn = getConnection();
            stmt = conn.createStatement();
            String sql = "SELECT COUNT(*) FROM information_schema.schemata WHERE schema_name=\"" + database + "\"";
            System.out.println(sql);
            rs = stmt.executeQuery(sql);
            if (rs.next()) {
                if (rs.getInt(1) == 0) {
                    return false;
                } else {
                    return true;
                }
            }
            return false;
        } catch (Exception e) {
            throw new TenantException(e.getMessage(), Status.INTERNAL_SERVER_ERROR);
        } finally {
            try {
                if (rs != null) {
                    rs.close();
                }
                if (stmt != null) {
                    stmt.close();
                }
                if (conn != null) {
                    conn.close();
                }
            } catch (SQLException e) {
                throw new TenantException("mysql关闭连接失败：" + e.getMessage(), Status.INTERNAL_SERVER_ERROR);
            }
        }
    }

String sql = "SELECT COUNT(*) FROM information_schema.schemata WHERE schema_name=\"" + database + "\"";