Package org.apache.tomcat.jdbc.pool

Class JdbcInterceptor

java.lang.Object
org.apache.tomcat.jdbc.pool.JdbcInterceptor
All Implemented Interfaces:
InvocationHandler
Direct Known Subclasses:
AbstractCreateStatementInterceptor, ConnectionState, DisposableConnectionFacade, ProxyConnection, TrapException
public abstract class JdbcInterceptor extends Object implements InvocationHandler
Abstract class that is to be extended for implementations of interceptors. Everytime an operation is called on the Connection object the invoke(Object, Method, Object[]) method on the interceptor will be called. Interceptors are useful to change or improve behavior of the connection pool.
Interceptors can receive a set of properties. Each sub class is responsible for parsing the properties during runtime when they are needed or simply override the setProperties(Map) method. Properties arrive in a key-value pair of Strings as they were received through the configuration. This method is called once per cached connection object when the object is first configured.

  • Field Details

  • Constructor Details

    • JdbcInterceptor

      public JdbcInterceptor()
      Public constructor for instantiation through reflection

  • Method Details

    • invoke

      public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
      Gets invoked each time an operation on Connection is invoked.
      Specified by:
      invoke in interface InvocationHandler
      Throws:
      Throwable

    • getNext

      public JdbcInterceptor getNext()
      Returns the next interceptor in the chain
      Returns:
      the next interceptor in the chain

    • setNext

      public void setNext(JdbcInterceptor next)
      configures the next interceptor in the chain
      Parameters:
      next - The next chain item

    • compare

      public boolean compare(String name1, String name2)
      Performs a string comparison, using references unless the useEquals property is set to true.
      Parameters:
      name1 - The first name
      name2 - The second name
      Returns:
      true if name1 is equal to name2 based on useEquals

    • compare

      public boolean compare(String methodName, Method method)
      Compares a method name (String) to a method (Method) compare(String,String) Uses reference comparison unless the useEquals property is set to true
      Parameters:
      methodName - The method name
      method - The method
      Returns:
      true if the name matches

    • reset

      public abstract void reset(ConnectionPool parent, PooledConnection con)
      Gets called each time the connection is borrowed from the pool This means that if an interceptor holds a reference to the connection the interceptor can be reused for another connection.
      This method may be called with null as both arguments when we are closing down the connection.
      Parameters:
      parent - - the connection pool owning the connection
      con - - the pooled connection

    • disconnected

      public void disconnected(ConnectionPool parent, PooledConnection con, boolean finalizing)
      Called when Connection.close() is called on the underlying connection. This is to notify the interceptors, that the physical connection has been released. Implementation of this method should be thought through with care, as no actions should trigger an exception.
      Parameters:
      parent - - the connection pool that this connection belongs to
      con - - the pooled connection that holds this connection
      finalizing - - if this connection is finalizing. True means that the pooled connection will not reconnect the underlying connection

    • getProperties

      public Map<String,PoolProperties.InterceptorProperty> getProperties()
      Returns the properties configured for this interceptor
      Returns:
      the configured properties for this interceptor

    • setProperties

      public void setProperties(Map<String,PoolProperties.InterceptorProperty> properties)
      Called during the creation of an interceptor The properties can be set during the configuration of an interceptor Override this method to perform type casts between string values and object properties
      Parameters:
      properties - The properties

    • isUseEquals

      public boolean isUseEquals()
      Returns:
      true if the compare method uses the Object.equals(Object) method false if comparison is done on a reference level

    • setUseEquals

      public void setUseEquals(boolean useEquals)
      Set to true if string comparisons (for the compare(String, Method) and compare(String, String) methods) should use the Object.equals(Object) method The default is false
      Parameters:
      useEquals - true if equals will be used for comparisons

    • poolClosed

      public void poolClosed(ConnectionPool pool)
      This method is invoked by a connection pool when the pool is closed. Interceptor classes can override this method if they keep static variables or other tracking means around. This method is only invoked on a single instance of the interceptor, and not on every instance created.
      Parameters:
      pool - - the pool that is being closed.

    • poolStarted

      public void poolStarted(ConnectionPool pool)
      This method is invoked by a connection pool when the pool is first started up, usually when the first connection is requested. Interceptor classes can override this method if they keep static variables or other tracking means around. This method is only invoked on a single instance of the interceptor, and not on every instance created.
      Parameters:
      pool - - the pool that is being closed.