Proxy for a target R2DBC ConnectionFactory, adding awareness of Spring-managed transactions.

Data access code that should remain unaware of Spring's data access support can work with this proxy to seamlessly participate in Spring-managed transactions. Note that the transaction manager, for example R2dbcTransactionManager, still needs to work with the underlying ConnectionFactory, not with this proxy.

Make sure that TransactionAwareConnectionFactoryProxy is the outermost ConnectionFactory of a chain of ConnectionFactory proxies/adapters. TransactionAwareConnectionFactoryProxy can delegate either directly to the target connection pool or to some intermediary proxy/adapter.

Delegates to ConnectionFactoryUtils for automatically participating in thread-bound transactions, for example managed by R2dbcTransactionManager. create() calls and close calls on returned Connection will behave properly within a transaction, i.e. always operate on the transactional Connection. If not within a transaction, normal ConnectionFactory behavior applies.

This proxy allows data access code to work with the plain R2DBC API. However, if possible, use Spring's ConnectionFactoryUtils or DatabaseClient to get transaction participation even without a proxy for the target ConnectionFactory, avoiding the need to define such a proxy in the first place.

Note

This ConnectionFactory proxy needs to return wrapped Connections in order to handle close calls properly. Use Wrapped#unwrap() to retrieve the native R2DBC Connection.

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	TransactionAwareConnectionFactoryProxy.TransactionAwareInvocationHandler Invocation handler that delegates close calls on R2DBC Connections to `ConnectionFactoryUtils` for being aware of context-bound transactions.

Access	Constructor and Description
public	TransactionAwareConnectionFactoryProxy(ConnectionFactory the target `ConnectionFactory` targetConnectionFactory) Create a new `TransactionAwareConnectionFactoryProxy`.

Method Summary

Modifier and Type	Method and Description
public Mono<Connection>	Returns: a transactional `Connection` if any, a new one else. create() Overrides org.springframework.r2dbc.connection.DelegatingConnectionFactory.create. Implements io.r2dbc.spi.ConnectionFactory.create. Delegates to `ConnectionFactoryUtils` for automatically participating in Spring-managed transactions.
protected Mono<Connection>	Returns: the wrapped `Connection`. getTransactionAwareConnectionProxy(ConnectionFactory the `ConnectionFactory` that the `Connection` came from targetConnectionFactory) Wraps the given `Connection` with a proxy that delegates every method call to it but delegates `close()` calls to `ConnectionFactoryUtils`.
private static Connection	proxyConnection(Connection connection, ConnectionFactory targetConnectionFactory)

Inherited from org.springframework.r2dbc.connection.DelegatingConnectionFactory:: getMetadata getTargetConnectionFactory unwrap

TransactionAwareConnectionFactoryProxy	back to summary
public TransactionAwareConnectionFactoryProxy(ConnectionFactory targetConnectionFactory) Create a new `TransactionAwareConnectionFactoryProxy`. Parameters targetConnectionFactory:ConnectionFactory the target `ConnectionFactory`

Method Detail

create back to summary

create	back to summary
public Mono<Connection> create() Overrides org.springframework.r2dbc.connection.DelegatingConnectionFactory.create. Implements io.r2dbc.spi.ConnectionFactory.create. Delegates to `ConnectionFactoryUtils` for automatically participating in Spring-managed transactions. Returns:Mono<Connection> a transactional `Connection` if any, a new one else. Annotations @Override See Also `ConnectionFactoryUtils#doGetConnection`

public Mono<Connection> create()

Overrides org.springframework.r2dbc.connection.DelegatingConnectionFactory.create.

Implements io.r2dbc.spi.ConnectionFactory.create.

Delegates to ConnectionFactoryUtils for automatically participating in Spring-managed transactions.

Returns:Mono<Connection>

a transactional Connection if any, a new one else.

Annotations

@Override

getTransactionAwareConnectionProxy back to summary

getTransactionAwareConnectionProxy	back to summary
protected Mono<Connection> getTransactionAwareConnectionProxy(ConnectionFactory targetConnectionFactory) Wraps the given `Connection` with a proxy that delegates every method call to it but delegates `close()` calls to `ConnectionFactoryUtils`. Parameters targetConnectionFactory:ConnectionFactory the `ConnectionFactory` that the `Connection` came from Returns:Mono<Connection> the wrapped `Connection`. See Also `Connection#close()`, `ConnectionFactoryUtils#doReleaseConnection`

protected Mono<Connection> getTransactionAwareConnectionProxy(ConnectionFactory targetConnectionFactory)

Wraps the given Connection with a proxy that delegates every method call to it but delegates close() calls to ConnectionFactoryUtils.

Parameters

targetConnectionFactory:ConnectionFactory: the ConnectionFactory that the Connection came from

Returns:Mono<Connection>

the wrapped Connection.

proxyConnection	back to summary
private static Connection proxyConnection(Connection connection, ConnectionFactory targetConnectionFactory)

org.springframework.r2dbc.connection back to summary

private Class TransactionAwareConnectionFactoryProxy.TransactionAwareInvocationHandler

Class Inheritance

extends Object
implements InvocationHandler

java.lang.Object
org.springframework.r2dbc.connection.TransactionAwareConnectionFactoryProxy.TransactionAwareInvocationHandler

All Implemented Interfaces

java.lang.reflect.InvocationHandler

Invocation handler that delegates close calls on R2DBC Connections to ConnectionFactoryUtils for being aware of context-bound transactions.

Field Summary

Modifier and Type	Field and Description
private boolean	closed
private final Connection	connection
private final ConnectionFactory	targetConnectionFactory

Constructor Summary

Access	Constructor and Description
pack-priv	TransactionAwareInvocationHandler(Connection connection, ConnectionFactory targetConnectionFactory)

Method Summary

Modifier and Type Method and Description

Modifier and Type	Method and Description
public Object	invoke(Object the proxy instance that the method was invoked on proxy, Method the `Method` instance corresponding to the interface method invoked on the proxy instance. The declaring class of the `Method` object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through. method, Object[] an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or `null` if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as `java.lang.Integer` or `java.lang.Boolean`. args) Implements java.lang.reflect.InvocationHandler.invoke. Processes a method invocation on a proxy instance and returns the result.
private String	proxyToString(Object proxy)

public Object

invoke(Object

the proxy instance that the method was invoked on

proxy, Method

the Method instance corresponding to the interface method invoked on the proxy instance. The declaring class of the Method object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through.

method, Object[]

an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as java.lang.Integer or java.lang.Boolean.

args)

Implements java.lang.reflect.InvocationHandler.invoke.

Processes a method invocation on a proxy instance and returns the result.

private String

proxyToString(Object proxy)

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

closed	back to summary
private boolean closed

connection	back to summary
private final Connection connection

targetConnectionFactory	back to summary
private final ConnectionFactory targetConnectionFactory

Constructor Detail

TransactionAwareInvocationHandler	back to summary
pack-priv TransactionAwareInvocationHandler(Connection connection, ConnectionFactory targetConnectionFactory)

Method Detail

invoke back to summary

invoke	back to summary
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable Implements java.lang.reflect.InvocationHandler.invoke. Doc from java.lang.reflect.InvocationHandler.invoke. Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with. Parameters proxy:Object the proxy instance that the method was invoked on method:Method the `Method` instance corresponding to the interface method invoked on the proxy instance. The declaring class of the `Method` object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through. args:Object[] an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or `null` if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as `java.lang.Integer` or `java.lang.Boolean`. Returns:Object the value to return from the method invocation on the proxy instance. If the declared return type of the interface method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is `null` and the interface method's return type is primitive, then a `NullPointerException` will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, a `ClassCastException` will be thrown by the method invocation on the proxy instance. Annotations @Override @Nullable Exceptions Throwable: the exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the `throws` clause of the interface method or to the unchecked exception types `java.lang.RuntimeException` or `java.lang.Error`. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the `throws` clause of the interface method, then an `UndeclaredThrowableException` containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.

public Object invoke(Object proxy, Method method, Object[] args) throws Throwable

Implements java.lang.reflect.InvocationHandler.invoke.

Doc from java.lang.reflect.InvocationHandler.invoke.

Processes a method invocation on a proxy instance and returns the result. This method will be invoked on an invocation handler when a method is invoked on a proxy instance that it is associated with.

Parameters

proxy:Object: the proxy instance that the method was invoked on
method:Method: the Method instance corresponding to the interface method invoked on the proxy instance. The declaring class of the Method object will be the interface that the method was declared in, which may be a superinterface of the proxy interface that the proxy class inherits the method through.
args:Object[]: an array of objects containing the values of the arguments passed in the method invocation on the proxy instance, or null if interface method takes no arguments. Arguments of primitive types are wrapped in instances of the appropriate primitive wrapper class, such as java.lang.Integer or java.lang.Boolean.

Returns:Object

the value to return from the method invocation on the proxy instance. If the declared return type of the interface method is a primitive type, then the value returned by this method must be an instance of the corresponding primitive wrapper class; otherwise, it must be a type assignable to the declared return type. If the value returned by this method is null and the interface method's return type is primitive, then a NullPointerException will be thrown by the method invocation on the proxy instance. If the value returned by this method is otherwise not compatible with the interface method's declared return type as described above, a ClassCastException will be thrown by the method invocation on the proxy instance.

Annotations

@Override
@Nullable

Exceptions

Throwable:: the exception to throw from the method invocation on the proxy instance. The exception's type must be assignable either to any of the exception types declared in the throws clause of the interface method or to the unchecked exception types java.lang.RuntimeException or java.lang.Error. If a checked exception is thrown by this method that is not assignable to any of the exception types declared in the throws clause of the interface method, then an UndeclaredThrowableException containing the exception that was thrown by this method will be thrown by the method invocation on the proxy instance.

proxyToString	back to summary
private String proxyToString(Object proxy)

public Class TransactionAwareConnectionFactoryProxy

Nested and Inner Type Summary

Constructor Summary

Method Summary

Constructor Detail

Method Detail

private Class TransactionAwareConnectionFactoryProxy.TransactionAwareInvocationHandler

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail