C3P0ProxyConnection (c3p0-0.9.5.5 API Documentation)
Date: 2019-12-11

com.mchange.v2.c3p0

## Interface C3P0ProxyConnection

- All Superinterfaces:
    java.lang.AutoCloseable, java.sql.Connection, java.sql.Wrapper
  All Known Implementing Classes:
    NewProxyConnection

      public interface C3P0ProxyConnection
      extends java.sql.Connection

  Most clients need never use or know about this interface -- c3p0-provided Connections can be treated like any other Connection.

  An interface implemented by proxy Connections returned by c3p0 PooledDataSources. It provides protected access to the underlying dbms-vendor specific Connection, which may be useful if you want to access non-standard API offered by your jdbc driver.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static java.lang.Object` | `RAW_CONNECTION` A token representing an unwrapped, unproxied jdbc Connection for use in `rawConnectionOperation(java.lang.reflect.Method, java.lang.Object, java.lang.Object[])`

    - ### Fields inherited from interface java.sql.Connection

      `TRANSACTION_NONE, TRANSACTION_READ_COMMITTED, TRANSACTION_READ_UNCOMMITTED, TRANSACTION_REPEATABLE_READ, TRANSACTION_SERIALIZABLE`

  - ### Method Summary

    All Methods Instance Methods Abstract Methods
    Modifier and Type | Method and Description
    --- | ---
    `java.lang.Object` | `rawConnectionOperation(java.lang.reflect.Method m, java.lang.Object target, java.lang.Object[] args)` Allows one to work with the unproxied, raw Connection.

    - ### Methods inherited from interface java.sql.Connection

      `abort, clearWarnings, close, commit, createArrayOf, createBlob, createClob, createNClob, createSQLXML, createStatement, createStatement, createStatement, createStruct, getAutoCommit, getCatalog, getClientInfo, getClientInfo, getHoldability, getMetaData, getNetworkTimeout, getSchema, getTransactionIsolation, getTypeMap, getWarnings, isClosed, isReadOnly, isValid, nativeSQL, prepareCall, prepareCall, prepareCall, prepareStatement, prepareStatement, prepareStatement, prepareStatement, prepareStatement, prepareStatement, releaseSavepoint, rollback, rollback, setAutoCommit, setCatalog, setClientInfo, setClientInfo, setHoldability, setNetworkTimeout, setReadOnly, setSavepoint, setSavepoint, setSchema, setTransactionIsolation, setTypeMap`

    - ### Methods inherited from interface java.sql.Wrapper

      `isWrapperFor, unwrap`

- - ### Field Detail

    - #### RAW_CONNECTION

          static final java.lang.Object RAW_CONNECTION

      A token representing an unwrapped, unproxied jdbc Connection for use in `rawConnectionOperation(java.lang.reflect.Method, java.lang.Object, java.lang.Object[])`

  - ### Method Detail

    - #### rawConnectionOperation

          java.lang.Object rawConnectionOperation(java.lang.reflect.Method m,
                                                  java.lang.Object target,
                                                  java.lang.Object[] args)
                                           throws java.lang.IllegalAccessException,
                                                  java.lang.IllegalArgumentException,
                                                  java.lang.reflect.InvocationTargetException,
                                                  java.sql.SQLException

      Allows one to work with the unproxied, raw Connection. Some database companies never got over the "common interfaces mean no more vendor lock-in!" thing, and offer non-standard API on their Connections. This method permits you to "pierce" the connection-pooling layer to call non-standard methods on the original Connection, or to pass the original Connections to functions that are not implementation neutral.

      To use this functionality, you'll need to cast a Connection retrieved from a c3p0 PooledDataSource to a C3P0ProxyConnection.

      This method works by making a reflective call of method `m` on Object `target` (which may be null for static methods), passing and argument list `args`. For the method target, or for any argument, you may substitute the special token `C3P0ProxyConnection.RAW_CONNECTION`

      Any Statements or ResultSets returned by the operation will be proxied and c3p0-managed, meaning that these resources will be automatically closed if the user does not close them first when this Connection is checked back into the pool. Any other resources returned by the operation are the user's responsibility to clean up!

      Incautious use of this method can corrupt the Connection pool, by breaking the invariant that all checked-in Connections should be equivalent. If your vendor supplies API that allows you to modify the state or configuration of a Connection in some nonstandard way, you might use this method to do so, and then check the Connection back into the pool. When you fetch another Connection from the PooledDataSource, it will be undefined whether the Connection returned will have your altered configuration, or the default configuration of a "fresh" Connection. Thus, it is inadvisable to use this method to call nonstandard mutators.

      Throws:
        `java.lang.IllegalAccessException`
        `java.lang.IllegalArgumentException`
        `java.lang.reflect.InvocationTargetException`
        `java.sql.SQLException`