Modul com.github.hypfvieh.java.utils
Package com.github.hypfvieh.db

Klasse SimpleDatabaseConnector

java.lang.Object
com.github.hypfvieh.db.SimpleDatabaseConnector
public class SimpleDatabaseConnector extends Object
Simple class to allow connection to any JDBC compatible database. Allows to send any SQL statement to the database as well as retrieving data (SELECT) from a database in a List-of-Map format.

All columns selected will be accessible by iterating through the list of maps. Each item of the list represents one row as HashMap where each key is one column. Column names are case insensitive!

It allows caching of retrieved DB results in JSON format. If caching is enabled it will automatically use the offline cache if database is unreachable.

One instance of SimpleDatabaseConnector can store multiple select queries in offline cache (map of SQL-Query(key) and Result (value)).

Sample Usage: 
 
    IDatabaseConnector sdc = newSqlConnectorInstance(getDatabaseConnectionParameters("EnxMasterdata"), true); // use false to disable cache

        if (sdc.openDatabase() || sdc.isOffline()) { // if cache is disabled you should stop if isOffline() == true
            List<Map<String, String>> selectedRows = sdc.executeSelectQuery(true, sqlGattungString);
            for (Map<String, String> tableEntry : selectedRows) {
                isin2enx.put(tableEntry.get("isin"), tableEntry.get("enx_code"));
            }
        }
Seit:
1.0.1
Autor:
hypfvieh

  • Konstruktordetails

    • SimpleDatabaseConnector

      public SimpleDatabaseConnector(DbConnParms _connectionParams)

  • Methodendetails

    • openDatabase

      public final boolean openDatabase() throws InvalidClassException, ClassNotFoundException
      Trys to open a connection to the given database parameters. Returns true if connection could be established, false otherwise. Throws InvalidClassException if given SQL-Driver is not JDBC compatible. Throws ClassNotFoundException if given SQL-Driver class could not be found. Throws SQLException on any connection error.
      Gibt zurück:
      true if connected, false otherwise
      Löst aus:
      InvalidClassException - if class is not a java.sql.Driver derivative
      ClassNotFoundException - if class could not be found

    • getDbConnection

      public Connection getDbConnection()

    • closeDatabase

      public void closeDatabase() throws SQLException
      Closes the database connection if it was previously connected.
      Löst aus:
      SQLException - if closing fails

    • isDbOpen

      public boolean isDbOpen()
      Returns true if database has been opened.
      Gibt zurück:
      true if open, false otherwise

    • executeBatchQuery

      public boolean executeBatchQuery(String _sqlQuery, List<Object[]> _sqlParameters, int _batchSize)
      Run update/inserts as batch update. Will fallback to sequential insert/update if database implemenation does not support batch.

      Attention: Do not use batch when calling stored procedures in oracle databases, as this is not supported by oracle and will not work.

      Parameter:
      _sqlQuery - sql query to use (with '?' placeholders)
      _sqlParameters - an array of values for replacing '?' placeholders in query
      _batchSize - batch size to use
      Gibt zurück:
      true on successful execution, false if any error occurred

    • executeQuery

      public boolean executeQuery(String _sql, Object... _args)
      Executes an sql query.
      Parameter:
      _sql - query to execute
      _args - arguments to fill-in placeholders in query, can be omitted if none needed
      Gibt zurück:
      true if SQL-query returns an update-count, false on error or if result is resultset instead of update count.

    • executeSelectQuery

      public List<Map<String,String>> executeSelectQuery(String _sql, Object... _args)
      Returns the result of an SQL Select-PreparedStatement as list of maps where each key in the map is a column.
      Parameter:
      _sql - the sql statement to execute (can use '?' placeholder which will be replaced by the parameters in _args)
      _args - parameters to replace '?'- placeholder insert _sql (if none, this can be omitted)
      Gibt zurück:
      list of maps with the result of the query, each list entry is one row of the database

    • createPreparedStatement

      public PreparedStatement createPreparedStatement(String _sql)
      Creates a prepared statement which can be used for batch statements.
      Parameter:
      _sql - sql to create prepared statement for
      Gibt zurück:
      new prepared statement or null on error

    • executeQuery

      public boolean executeQuery(PreparedStatement _ps)
      Execute a previously created prepared statement (update or delete).
      Parameter:
      _ps - prepared statement to execute
      Gibt zurück:
      true if execution successfully, false otherwise

    • isSupportsBatch

      public boolean isSupportsBatch()

    • setAutoCommit

      public void setAutoCommit(boolean _onOff) throws SQLException
      Enable/Disable autocommit on database connection.
      Parameter:
      _onOff - enable/disable autocommit
      Löst aus:
      SQLException - if autocommit option cannot be changed

    • isAutoCommit

      public boolean isAutoCommit() throws SQLException
      Returns status of autocommit option.
      Gibt zurück:
      true if autocommit enabled, false otherwise
      Löst aus:
      SQLException - if autocommit option status could not be determined

    • toString

      public final String toString()
      Setzt außer Kraft:
      toString in Klasse Object