ConnectionHandler (JChem Base API documentation (c) 1998-2021 ChemAxon Ltd.)

java.lang.Object
- chemaxon.util.ErrorHandler
- - chemaxon.util.ConnectionHandler

```
@PublicAPI
public class ConnectionHandler
extends ErrorHandler
```
A JavaBean for connecting to relational databases using JDBC. See JDBC home site for more details on JDBC connections. The JDBC driver you are using will provide information on setting the url property.
This JavaBean stores one JChem specific property, the name of the property table. Its default value is "JChemProperties". See the multiuser section for details. If you don't intend to use the connection in transaction, it is preferred to allow ConnectionHandler to commit connection. In this case use constructors containing isConnectionCommitable parameter set to true.
Example #1 (connection is not used in transaction):
```
 ConnectionHandler ch = new ConnectionHandler(true);
 ch.setDriver("oracle.jdbc.OracleDriver");
 ch.setUrl("jdbc:oracle:thin:@inhale:1521:demodb");
 ch.setLoginName("INTERNAL");
 ch.setPassword("oracle");
 ch.connectToDatabase();
 
```
Example #2 (connection might be used in transaction):
```
 Connection con = ... // E.g. from connection pool, ...
 ConnectionHandler ch = new ConnectionHandler(con, ConnectionHandler.DEFAULT_PROPERTY_TABLE);
 
```
Author:

Ferenc Csizmadia, Szilard Dorant, Tamas Csizmazia

Field Summary

Fields
Modifier and Type Field and Description

static java.lang.String DEFAULT_PROPERTY_TABLE
- Fields inherited from class chemaxon.util.ErrorHandler
  CLASS_NOT_FOUND_ERROR, DATABASE_SEARCH_ERROR, exception, ILLEGAL_ACCESS_ERROR, INSTANTIATION_ERROR, IO_ERROR, MAX_SEARCH_FREQUENCY_EXCEEDED_ERROR, MOL_FORMAT_ERROR, NO_ERROR, SQL_ERROR, UNIDENTIFIED_ERROR

Fields
Modifier and Type	Field and Description
`static java.lang.String`	`DEFAULT_PROPERTY_TABLE`

Constructor Summary

Constructors
Constructor and Description
`ConnectionHandler()` Creates new ConnectionHandler Connection will automatically be non-commitable (see `isCommitable()`) to preserve compatibility with previous versions.
`ConnectionHandler(boolean isConnectionCommitable)` Creates new ConnectionHandler
`ConnectionHandler(ConnectionHandler ch)` Creates new ConnectionHandler based on the settings of an other ConnectionHandler.
`ConnectionHandler(ConnectionHandler ch, boolean isConnectionCommitable)` Creates new ConnectionHandler based on the settings of an other ConnectionHandler.
`ConnectionHandler(java.sql.Connection con, java.lang.String propertyTableName)` Creates a new ConnectionHandler and sets the connection to an externally created Connection (e.g.
`ConnectionHandler(java.sql.Connection con, java.lang.String propertyTableName, boolean isConnectionCommitable)` Creates a new ConnectionHandler and sets the connection to an externally created Connection (e.g.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`close()` Closes the connection to the database.
`void`	`connectToDatabase()` Connects to the database.
`void`	`disconnect()` Disconnect from the database.
`protected void`	`finalize()`
`java.sql.Connection`	`getConnection()` Getter for property `connection`.
`java.lang.String`	`getDriver()` Getter for property `driver`.
`java.lang.String`	`getDriverName()` Getter for property `driverName`.
`static ConnectionHandler`	`getInstance(int dbType, java.lang.String host, int port, java.lang.String database, java.lang.String username, java.lang.String password)` Creates a ConnectionHandler using the appropriate driver and url determined by given database type, host, port and name.
`java.lang.String`	`getLoginName()` Getter for property `loginName`.
`java.lang.String`	`getPassword()` Getter for property `password`.
`java.lang.String`	`getPropertyTable()` Getter for property `propertyTable`.
`boolean`	`getRememberPassword()` Getter for property `rememberPassword`.
`java.lang.String`	`getUrl()` Getter for property `url`.
`boolean`	`isCommitable()`
`boolean`	`isConnected()` Getter for property `connected`.
`boolean`	`isCopyable()`
`boolean`	`loadValuesFromProperties(java.util.Properties settings)` Loads connection data from settings.
`void`	`setConnected(boolean connected)` Setter for property `connected`.
`void`	`setConnection(java.sql.Connection con)` Sets the connection to an externally created Connection (e.g.
`void`	`setDriver(java.lang.String driver)` Setter for property `driver`.
`void`	`setDriverName(java.lang.String driverName)` Setter for property `driverName`.
`void`	`setLoginName(java.lang.String loginName)` Setter for property `loginName`.
`void`	`setPassword(java.lang.String password)` Setter for property `password`.
`void`	`setPropertyTable(java.lang.String propertyTableName)` Setter for property `propertyTable`.
`void`	`setRememberPassword(boolean rememberPassword)` Setter for property `rememberPassword`.
`void`	`setUrl(java.lang.String url)` Setter for property `url`.
`void`	`storeValuesToProperties(java.util.Properties settings)` Stores connection data in properties.
`java.lang.String`	`toString()`

Methods inherited from class chemaxon.util.ErrorHandler
checkError, checkException, getError, getErrorMessage, getException, getStackTrace

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - DEFAULT_PROPERTY_TABLE
```
public static final java.lang.String DEFAULT_PROPERTY_TABLE
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - ConnectionHandler
```
public ConnectionHandler()
```
    Creates new ConnectionHandler Connection will automatically be non-commitable (see isCommitable()) to preserve compatibility with previous versions.
  - ConnectionHandler
```
public ConnectionHandler(boolean isConnectionCommitable)
```
    Creates new ConnectionHandler
    
    Parameters:
    
    isConnectionCommitable - if true, the connection can be committed at the discretion of JChem. Please note, that no commit or multiple commits may occur in this case.
    
    Since:
    
    JChem 5.9
  - ConnectionHandler
```
public ConnectionHandler(java.sql.Connection con,
                         java.lang.String propertyTableName)
```
    Creates a new ConnectionHandler and sets the connection to an externally created Connection (e.g. from a connection pool).
    Since connection data (url, driver, loginName, password) is unknown, these properties are set to null. Warning: after instantiating a ConnectionHandler by using this constructor, do not call connectToDatabase()!
    
    Parameters:
    
    con - An open (connected) Connection object that will be used for database operations.
    
    propertyTableName - name of the jchem property table to use
    
    Since:
    
    JChem 5.5
  - ConnectionHandler
```
public ConnectionHandler(java.sql.Connection con,
                         java.lang.String propertyTableName,
                         boolean isConnectionCommitable)
```
    Creates a new ConnectionHandler and sets the connection to an externally created Connection (e.g. from a connection pool).
    Since connection data (url, driver, loginName, password) is unknown, these properties are set to null. Warning: after instantiating a ConnectionHandler by using this constructor, do not call connectToDatabase()!
    
    Parameters:
    
    con - An open (connected) Connection object that will be used for database operations.
    
    propertyTableName - name of the jchem property table to use
    
    isConnectionCommitable - if true, the connection can be committed at the discretion of JChem. Please note, that no commit or multiple commits may occur in this case.
    
    Since:
    
    JChem 5.9
  - ConnectionHandler
```
public ConnectionHandler(ConnectionHandler ch)
```
    Creates new ConnectionHandler based on the settings of an other ConnectionHandler. Does not copies Connection, and does not connect.
    
    Parameters:
    
    ch - the other ConnectionHandler
    
    Since:
    
    JChem 2.2
  - ConnectionHandler
```
public ConnectionHandler(ConnectionHandler ch,
                         boolean isConnectionCommitable)
```
    Creates new ConnectionHandler based on the settings of an other ConnectionHandler.
    
    Parameters:
    
    ch - the other ConnectionHandler
    
    isConnectionCommitable - if true, the connection can be committed at the discretion of JChem. Please note, that no commit or multiple commits may occur in this case.
    
    Since:
    
    JChem 5.9
- Method Detail
  - getInstance
```
public static ConnectionHandler getInstance(int dbType,
                                            java.lang.String host,
                                            int port,
                                            java.lang.String database,
                                            java.lang.String username,
                                            java.lang.String password)
```
    Creates a ConnectionHandler using the appropriate driver and url determined by given database type, host, port and name.
    Usage:
```
 ConnectionHandler.getInstance(DatabaseConstants.POSTGRESQL, "localhost", 5432, "demodb", "adminuser", "adminpass");
 
```
    Parameters:
    
    dbType - Database type defined in DatabaseConstants class.
    
    host - Server name or IP-address.
    
    port - Server port number or default if negative number is given.
    
    database - Name of the concrete database (or schema) we want to connect.
    
    username - Username.
    
    password - Password.
    
    Returns:
    
    ConnectionHandler or null if the database type is unknown
    
    Since:
    
    JChem 5.2
  - getDriverName
```
public java.lang.String getDriverName()
```
    Getter for property driverName.
    
    Returns:
    
    Value of property driverName.
  - setDriverName
```
public void setDriverName(java.lang.String driverName)
```
    Setter for property driverName.
    
    Parameters:
    
    driverName - New value of property driverName.
  - getDriver
```
public java.lang.String getDriver()
```
    Getter for property driver.
    
    Returns:
    
    Value of property driver.
  - setDriver
```
public void setDriver(java.lang.String driver)
```
    Setter for property driver.
    
    Parameters:
    
    driver - New value of property driver.
  - getUrl
```
public java.lang.String getUrl()
```
    Getter for property url.
    
    Returns:
    
    Value of property url.
  - setUrl
```
public void setUrl(java.lang.String url)
```
    Setter for property url.
    
    Parameters:
    
    url - New value of property url.
  - getLoginName
```
public java.lang.String getLoginName()
```
    Getter for property loginName.
    
    Returns:
    
    Value of property loginName.
  - setLoginName
```
public void setLoginName(java.lang.String loginName)
```
    Setter for property loginName.
    
    Parameters:
    
    loginName - New value of property loginName.
  - getPassword
```
public java.lang.String getPassword()
```
    Getter for property password.
    
    Returns:
    
    Value of property password.
  - setPassword
```
public void setPassword(java.lang.String password)
```
    Setter for property password.
    
    Parameters:
    
    password - New value of property password.
  - getPropertyTable
```
public java.lang.String getPropertyTable()
```
    Getter for property propertyTable.
    
    Returns:
    
    Value of property propertyTable.
  - setPropertyTable
```
public void setPropertyTable(java.lang.String propertyTableName)
```
    Setter for property propertyTable.
    
    Parameters:
    
    propertyTableName - New value of property propertyTable.
  - getRememberPassword
```
public boolean getRememberPassword()
```
    Getter for property rememberPassword.
    
    Returns:
    
    Value of property rememberPassword.
  - setRememberPassword
```
public void setRememberPassword(boolean rememberPassword)
```
    Setter for property rememberPassword.
    
    Parameters:
    
    rememberPassword - New value of property rememberPassword.
  - isConnected
```
public boolean isConnected()
```
    Getter for property connected.
    
    Returns:
    
    Value of property connected.
  - setConnected
```
public void setConnected(boolean connected)
                  throws java.sql.SQLException,
                         java.lang.ClassNotFoundException,
                         java.lang.InstantiationException,
                         java.lang.IllegalAccessException
```
    Setter for property connected.
    
    Parameters:
    
    connected - New value of property connected.
    
    Throws:
    
    java.sql.SQLException - if the database encounters a problem
    
    java.lang.ClassNotFoundException - indicates jdbc driver problem
    
    java.lang.InstantiationException - indicates jdbc driver problem
    
    java.lang.IllegalAccessException - indicates jdbc driver problem
  - getConnection
```
public java.sql.Connection getConnection()
```
    Getter for property connection.
    
    Returns:
    
    Value of property connection.
  - setConnection
```
public final void setConnection(java.sql.Connection con)
```
    Sets the connection to an externally created Connection (e.g. from a connection pool).
    Since connection data (url, driver, loginName, password) is unknown, these properties are set to null. Warning: after calling setConnection(Connection) do not call connectToDatabase()!
    
    Parameters:
    
    con - An open (connected) Connection object that will be used for database operations.
  - isCommitable
```
public boolean isCommitable()
```
    Returns:
    
    true if the connection is commitable
  - connectToDatabase
```
public void connectToDatabase()
                       throws java.sql.SQLException,
                              java.lang.ClassNotFoundException
```
    Connects to the database. Creates a new connection using url, driver, loginName, password properties.
    Warning: do not call if you've already set a connection by calling setConnection(Connection)!
    
    Throws:
    
    java.sql.SQLException - if a database error occurs.
    
    java.lang.ClassNotFoundException - if the JDBC driver class for the required database is not found on the classpath.
  - disconnect
```
public void disconnect()
                throws java.sql.SQLException
```
    Disconnect from the database. If a connection is open, it will be closed. getConnection() returns null after calling this method.
    
    Throws:
    
    java.sql.SQLException - if the database encounters a problem
  - close
```
public void close()
           throws java.sql.SQLException
```
    Closes the connection to the database.
    
    Throws:
    
    java.sql.SQLException - if the database encounters a problem
  - loadValuesFromProperties
```
public boolean loadValuesFromProperties(java.util.Properties settings)
```
    Loads connection data from settings. Parameter names (keys in properties):
    - "connection.jdbcDriverName" (optional)
    - "connection.jdbcDriver" (mandatory)
    - "connection.jdbcUrl" (mandatory)
    - "connection.login" (optional, default: "")
    - "connection.password" (optional)
    - "connection.propertyTable" (optional, default: "JChemProperties")
    Parameters:
    
    settings - the connection parameter settings
    
    Returns:
    
    true if the settings provide valid connection data
  - storeValuesToProperties
```
public void storeValuesToProperties(java.util.Properties settings)
```
    Stores connection data in properties. Parameter names (keys in properties):
    - "connection.jdbcDriverName" (optional)
    - "connection.jdbcDriver" (mandatory)
    - "connection.jdbcUrl" (mandatory)
    - "connection.login" (optional, default: "")
    - "connection.password" (optional)
    - "connection.propertyTable" (optional, default: "JChemProperties")
    Parameters:
    
    settings - the properties to be filled with connection data
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - finalize
```
protected void finalize()
                 throws java.lang.Throwable
```
    Overrides:
    
    finalize in class java.lang.Object
    
    Throws:
    
    java.lang.Throwable
  - isCopyable
```
public boolean isCopyable()
```
    Returns:
    
    true if the connection is copyable

Class ConnectionHandler

Field Summary

Fields inherited from class chemaxon.util.ErrorHandler

Constructor Summary

Method Summary

Methods inherited from class chemaxon.util.ErrorHandler

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_PROPERTY_TABLE

Constructor Detail

ConnectionHandler

ConnectionHandler

ConnectionHandler

ConnectionHandler

ConnectionHandler

ConnectionHandler

Method Detail

getInstance

getDriverName

setDriverName

getDriver

setDriver

getUrl

setUrl

getLoginName

setLoginName

getPassword

setPassword

getPropertyTable

setPropertyTable

getRememberPassword

setRememberPassword

isConnected

setConnected

getConnection

setConnection

isCommitable

connectToDatabase

disconnect

close

loadValuesFromProperties

storeValuesToProperties

toString

finalize

isCopyable