com.mchange.v2.c3p0.C3P0ProxyStatement Maven / Gradle / Ivy
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package com.mchange.v2.c3p0;
import java.sql.Statement;
import java.sql.SQLException;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
/**
* Most clients need never use or know about this interface -- c3p0-provided Statements
* can be treated like any other Statement.
*
* 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.
*/
public interface C3P0ProxyStatement extends Statement
{
/**
* A token representing an unwrapped, unproxied jdbc Connection
* for use in {@link #rawStatementOperation}
*/
public final static Object RAW_STATEMENT = new Object();
/**
*
Allows one to work with the unproxied, raw vendor-provided Statement . Some
* database companies never got over the "common interfaces mean
* no more vendor lock-in!" thing, and offer non-standard API
* on their Statements. This method permits you to "pierce" the
* connection-pooling layer to call non-standard methods on the
* original Statement, or to pass the original Statement to
* functions that are not implementation neutral.
*
* To use this functionality, you'll need to cast a Statement
* retrieved from a c3p0-provided Connection to a
* C3P0ProxyStatement.
*
* 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 C3P0ProxyStatement.RAW_STATEMENT
*
* Any 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 Statement is closed or checked
* into the statement cache. Any other resources returned by the operation are the user's
* responsibility to clean up!
*
* If you have turned statement pooling on, incautious use of this method can corrupt the
* PreparedStatement cache, by breaking the invariant
* that all cached PreparedStatements should be equivalent to a PreparedStatement newly created
* with the same arguments to prepareStatement(...) or prepareCall(...). If your vendor supplies API
* that allows you to modify the state or configuration of a Statement in some nonstandard way,
* and you do not undo this modification prior to closing the Statement or the Connection that
* prepared it, future preparers of the same Statement may or may not see your modification,
* depending on your use of the cache. Thus, it is inadvisable to use this method to call
* nonstandard mutators on PreparedStatements if statement pooling is turned on..
*/
public Object rawStatementOperation(Method m, Object target, Object[] args)
throws IllegalAccessException, IllegalArgumentException, InvocationTargetException, SQLException;
}