Java compact2, compact3 java.sql Class DriverManager（JDK8）

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Java™ Platform
Standard Ed. 8

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java.lang.Object
- java.sql.DriverManager

```
public class DriverManager
extends Object
```
The basic service for managing a set of JDBC drivers.
NOTE: The DataSource interface, new in the JDBC 2.0 API, provides another way to connect to a data source. The use of a DataSource object is the preferred means of connecting to a data source.

As part of its initialization, the DriverManager class will attempt to load the driver classes referenced in the "jdbc.drivers" system property. This allows a user to customize the JDBC Drivers used by their applications. For example in your ~/.hotjava/properties file you might specify:
```
 jdbc.drivers=foo.bah.Driver:wombat.sql.Driver:bad.taste.ourDriver
 
```
The DriverManager methods getConnection and getDrivers have been enhanced to support the Java Standard Edition Service Provider mechanism. JDBC 4.0 Drivers must include the file META-INF/services/java.sql.Driver. This file contains the name of the JDBC drivers implementation of java.sql.Driver. For example, to load the my.sql.Driver class, the META-INF/services/java.sql.Driver file would contain the entry:
```
 my.sql.Driver
 
```
Applications no longer need to explicitly load JDBC drivers using Class.forName(). Existing programs which currently load JDBC drivers using Class.forName() will continue to work without modification.

When the method getConnection is called, the DriverManager will attempt to locate a suitable driver from amongst those loaded at initialization and those loaded explicitly using the same classloader as the current applet or application.

Starting with the Java 2 SDK, Standard Edition, version 1.3, a logging stream can be set only if the proper permission has been granted. Normally this will be done with the tool PolicyTool, which can be used to grant permission java.sql.SQLPermission "setLog".
See Also:

Driver, Connection

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static void`	`deregisterDriver(Driver driver)` Removes the specified driver from the `DriverManager`'s list of registered drivers.
`static Connection`	`getConnection(String url)` Attempts to establish a connection to the given database URL.
`static Connection`	`getConnection(String url, Properties info)` Attempts to establish a connection to the given database URL.
`static Connection`	`getConnection(String url, String user, String password)` Attempts to establish a connection to the given database URL.
`static Driver`	`getDriver(String url)` Attempts to locate a driver that understands the given URL.
`static Enumeration<Driver>`	`getDrivers()` Retrieves an Enumeration with all of the currently loaded JDBC drivers to which the current caller has access.
`static int`	`getLoginTimeout()` Gets the maximum time in seconds that a driver can wait when attempting to log in to a database.
`static PrintStream`	`getLogStream()` Deprecated. Use `getLogWriter`
`static PrintWriter`	`getLogWriter()` Retrieves the log writer.
`static void`	`println(String message)` Prints a message to the current JDBC log stream.
`static void`	`registerDriver(Driver driver)` Registers the given driver with the `DriverManager`.
`static void`	`registerDriver(Driver driver, DriverAction da)` Registers the given driver with the `DriverManager`.
`static void`	`setLoginTimeout(int seconds)` Sets the maximum time in seconds that a driver will wait while attempting to connect to a database once the driver has been identified.
`static void`	`setLogStream(PrintStream out)` Deprecated. Use `setLogWriter`
`static void`	`setLogWriter(PrintWriter out)` Sets the logging/tracing `PrintWriter` object that is used by the `DriverManager` and all drivers.

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

- Method Detail
  - getLogWriter
```
public static PrintWriter getLogWriter()
```
    Retrieves the log writer. The getLogWriter and setLogWriter methods should be used instead of the get/setlogStream methods, which are deprecated.
    
    Returns:
    
    a java.io.PrintWriter object
    
    Since:
    
    1.2
    
    See Also:
    
    setLogWriter(java.io.PrintWriter)
  - setLogWriter
```
public static void setLogWriter(PrintWriter out)
```
    Sets the logging/tracing PrintWriter object that is used by the DriverManager and all drivers.
    There is a minor versioning problem created by the introduction of the method setLogWriter. The method setLogWriter cannot create a PrintStream object that will be returned by getLogStream---the Java platform does not provide a backward conversion. As a result, a new application that uses setLogWriter and also uses a JDBC 1.0 driver that uses getLogStream will likely not see debugging information written by that driver.
    
    Starting with the Java 2 SDK, Standard Edition, version 1.3 release, this method checks to see that there is an SQLPermission object before setting the logging stream. If a SecurityManager exists and its checkPermission method denies setting the log writer, this method throws a java.lang.SecurityException.
    
    Parameters:
    
    out - the new logging/tracing PrintStream object; null to disable logging and tracing
    
    Throws:
    
    SecurityException - if a security manager exists and its checkPermission method denies setting the log writer
    
    Since:
    
    1.2
    
    See Also:
    
    SecurityManager.checkPermission(java.security.Permission), getLogWriter()
  - getConnection
```
public static Connection getConnection(String url,
                                       Properties info)
                                throws SQLException
```
    Attempts to establish a connection to the given database URL. The DriverManager attempts to select an appropriate driver from the set of registered JDBC drivers.
    Note: If a property is specified as part of the url and is also specified in the Properties object, it is implementation-defined as to which value will take precedence. For maximum portability, an application should only specify a property once.
    
    Parameters:
    
    url - a database url of the form jdbc:subprotocol:subname
    
    info - a list of arbitrary string tag/value pairs as connection arguments; normally at least a "user" and "password" property should be included
    
    Returns:
    
    a Connection to the URL
    
    Throws:
    
    SQLException - if a database access error occurs or the url is null
    
    SQLTimeoutException - when the driver has determined that the timeout value specified by the setLoginTimeout method has been exceeded and has at least tried to cancel the current database connection attempt
  - getConnection
```
public static Connection getConnection(String url,
                                       String user,
                                       String password)
                                throws SQLException
```
    Attempts to establish a connection to the given database URL. The DriverManager attempts to select an appropriate driver from the set of registered JDBC drivers.
    Note: If the user or password property are also specified as part of the url, it is implementation-defined as to which value will take precedence. For maximum portability, an application should only specify a property once.
    
    Parameters:
    
    url - a database url of the form jdbc:subprotocol:subname
    
    user - the database user on whose behalf the connection is being made
    
    password - the user's password
    
    Returns:
    
    a connection to the URL
    
    Throws:
    
    SQLException - if a database access error occurs or the url is null
    
    SQLTimeoutException - when the driver has determined that the timeout value specified by the setLoginTimeout method has been exceeded and has at least tried to cancel the current database connection attempt
  - getConnection
```
public static Connection getConnection(String url)
                                throws SQLException
```
    Attempts to establish a connection to the given database URL. The DriverManager attempts to select an appropriate driver from the set of registered JDBC drivers.
    
    Parameters:
    
    url - a database url of the form jdbc:subprotocol:subname
    
    Returns:
    
    a connection to the URL
    
    Throws:
    
    SQLException - if a database access error occurs or the url is null
    
    SQLTimeoutException - when the driver has determined that the timeout value specified by the setLoginTimeout method has been exceeded and has at least tried to cancel the current database connection attempt
  - getDriver
```
public static Driver getDriver(String url)
                        throws SQLException
```
    Attempts to locate a driver that understands the given URL. The DriverManager attempts to select an appropriate driver from the set of registered JDBC drivers.
    
    Parameters:
    
    url - a database URL of the form jdbc:subprotocol:subname
    
    Returns:
    
    a Driver object representing a driver that can connect to the given URL
    
    Throws:
    
    SQLException - if a database access error occurs
  - registerDriver
```
public static void registerDriver(Driver driver)
                           throws SQLException
```
    Registers the given driver with the DriverManager. A newly-loaded driver class should call the method registerDriver to make itself known to the DriverManager. If the driver is currently registered, no action is taken.
    
    Parameters:
    
    driver - the new JDBC Driver that is to be registered with the DriverManager
    
    Throws:
    
    SQLException - if a database access error occurs
    
    NullPointerException - if driver is null
  - registerDriver
```
public static void registerDriver(Driver driver,
                                  DriverAction da)
                           throws SQLException
```
    Registers the given driver with the DriverManager. A newly-loaded driver class should call the method registerDriver to make itself known to the DriverManager. If the driver is currently registered, no action is taken.
    
    Parameters:
    
    driver - the new JDBC Driver that is to be registered with the DriverManager
    
    da - the DriverAction implementation to be used when DriverManager#deregisterDriver is called
    
    Throws:
    
    SQLException - if a database access error occurs
    
    NullPointerException - if driver is null
    
    Since:
    
    1.8
  - deregisterDriver
```
public static void deregisterDriver(Driver driver)
                             throws SQLException
```
    Removes the specified driver from the DriverManager's list of registered drivers.
    If a null value is specified for the driver to be removed, then no action is taken.
    
    If a security manager exists and its checkPermission denies permission, then a SecurityException will be thrown.
    
    If the specified driver is not found in the list of registered drivers, then no action is taken. If the driver was found, it will be removed from the list of registered drivers.
    
    If a DriverAction instance was specified when the JDBC driver was registered, its deregister method will be called prior to the driver being removed from the list of registered drivers.
    
    Parameters:
    
    driver - the JDBC Driver to remove
    
    Throws:
    
    SQLException - if a database access error occurs
    
    SecurityException - if a security manager exists and its checkPermission method denies permission to deregister a driver.
    
    See Also:
    
    SecurityManager.checkPermission(java.security.Permission)
  - getDrivers
```
public static Enumeration<Driver> getDrivers()
```
    Retrieves an Enumeration with all of the currently loaded JDBC drivers to which the current caller has access.
    Note: The classname of a driver can be found using d.getClass().getName()
    
    Returns:
    
    the list of JDBC Drivers loaded by the caller's class loader
  - setLoginTimeout
```
public static void setLoginTimeout(int seconds)
```
    Sets the maximum time in seconds that a driver will wait while attempting to connect to a database once the driver has been identified.
    
    Parameters:
    
    seconds - the login time limit in seconds; zero means there is no limit
    
    See Also:
    
    getLoginTimeout()
  - getLoginTimeout
```
public static int getLoginTimeout()
```
    Gets the maximum time in seconds that a driver can wait when attempting to log in to a database.
    
    Returns:
    
    the driver login time limit in seconds
    
    See Also:
    
    setLoginTimeout(int)
  - setLogStream
```
@Deprecated
public static void setLogStream(PrintStream out)
```
    Deprecated. Use setLogWriter
    
    Sets the logging/tracing PrintStream that is used by the DriverManager and all drivers.
    In the Java 2 SDK, Standard Edition, version 1.3 release, this method checks to see that there is an SQLPermission object before setting the logging stream. If a SecurityManager exists and its checkPermission method denies setting the log writer, this method throws a java.lang.SecurityException.
    
    Parameters:
    
    out - the new logging/tracing PrintStream; to disable, set to null
    
    Throws:
    
    SecurityException - if a security manager exists and its checkPermission method denies setting the log stream
    
    See Also:
    
    SecurityManager.checkPermission(java.security.Permission), getLogStream()
  - getLogStream
```
@Deprecated
public static PrintStream getLogStream()
```
    Deprecated. Use getLogWriter
    
    Retrieves the logging/tracing PrintStream that is used by the DriverManager and all drivers.
    
    Returns:
    
    the logging/tracing PrintStream; if disabled, is null
    
    See Also:
    
    setLogStream(java.io.PrintStream)
  - println
```
public static void println(String message)
```
    Prints a message to the current JDBC log stream.
    
    Parameters:
    
    message - a log or tracing message

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Java™ Platform
Standard Ed. 8

All Classes

Summary:
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Field |
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Method

Detail:
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Java compact2, compact3 java.sql Class DriverManager（JDK8）

Class DriverManager

Method Summary

Methods inherited from class java.lang.Object

Method Detail

getLogWriter

setLogWriter

getConnection

getConnection

getConnection

getDriver

registerDriver

registerDriver

deregisterDriver

getDrivers

setLoginTimeout

getLoginTimeout

setLogStream

getLogStream

println