Reactive Oracle Client
The Reactive Oracle Client is a client for Oracle with a straightforward API focusing on scalability and low overhead.
Features
-
Event driven
-
Built-in connection pooling
-
Java 8 Date and Time
-
SSL/TLS
-
RxJava API
-
Cursor
-
Row streaming
Not supported yet
-
Prepared queries caching
-
Stored Procedures
Usage
To use the Reactive Oracle Client add the following dependency to the dependencies section of your build descriptor:
-
Maven (in your
pom.xml
):
<dependency>
<groupId>io.vertx</groupId>
<artifactId>vertx-oracle-client</artifactId>
<version>4.5.10</version>
</dependency>
-
Gradle (in your
build.gradle
file):
dependencies {
compile 'io.vertx:vertx-oracle-client:4.5.10'
}
Getting started
Here is the simplest way to connect, query and disconnect
OracleConnectOptions connectOptions = new OracleConnectOptions()
.setPort(1521)
.setHost("the-host")
.setDatabase("the-db")
.setUser("user")
.setPassword("secret");
// Pool options
PoolOptions poolOptions = new PoolOptions()
.setMaxSize(5);
// Create the client pool
Pool client = OracleBuilder.pool()
.with(poolOptions)
.connectingTo(connectOptions)
.build();
// A simple query
client
.query("SELECT * FROM users WHERE id='julien'")
.execute()
.onComplete(ar -> {
if (ar.succeeded()) {
RowSet<Row> result = ar.result();
System.out.println("Got " + result.size() + " rows ");
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
// Now close the pool
client.close();
});
Connecting to Oracle
Most of the time you will use a pool to connect to Oracle:
OracleConnectOptions connectOptions = new OracleConnectOptions()
.setPort(1521)
.setHost("the-host")
.setDatabase("the-db")
.setUser("user")
.setPassword("secret");
// Pool options
PoolOptions poolOptions = new PoolOptions()
.setMaxSize(5);
// Create the pooled client
Pool client = OracleBuilder.pool()
.with(poolOptions)
.connectingTo(connectOptions)
.using(vertx)
.build();
The pooled client uses a connection pool and any operation will borrow a connection from the pool to execute the operation and release it to the pool.
If you are running with Vert.x you can pass it your Vertx instance:
OracleConnectOptions connectOptions = new OracleConnectOptions()
.setPort(1521)
.setHost("the-host")
.setDatabase("the-db")
.setUser("user")
.setPassword("secret");
// Pool options
PoolOptions poolOptions = new PoolOptions()
.setMaxSize(5);
// Create the pooled client
Pool client = OracleBuilder.pool()
.with(poolOptions)
.connectingTo(connectOptions)
.using(vertx)
.build();
You need to release the pool when you don’t need it anymore:
pool.close();
When you need to execute several operations on the same connection, you need to use a client
connection
.
You can easily get one from the pool:
OracleConnectOptions connectOptions = new OracleConnectOptions()
.setPort(1521)
.setHost("the-host")
.setDatabase("the-db")
.setUser("user")
.setPassword("secret");
// Pool options
PoolOptions poolOptions = new PoolOptions()
.setMaxSize(5);
// Create the pooled client
Pool client = OracleBuilder.pool()
.with(poolOptions)
.connectingTo(connectOptions)
.using(vertx)
.build();
// Get a connection from the pool
client.getConnection().compose(conn -> {
System.out.println("Got a connection from the pool");
// All operations execute on the same connection
return conn
.query("SELECT * FROM users WHERE id='julien'")
.execute()
.compose(res -> conn
.query("SELECT * FROM users WHERE id='emad'")
.execute())
.onComplete(ar -> {
// Release the connection to the pool
conn.close();
});
}).onComplete(ar -> {
if (ar.succeeded()) {
System.out.println("Done");
} else {
System.out.println("Something went wrong " + ar.cause().getMessage());
}
});
Once you are done with the connection you must close it to release it to the pool, so it can be reused.
Configuration
There are several alternatives for you to configure the client.
Data Object
A simple way to configure the client is to specify a OracleConnectOptions
data object.
OracleConnectOptions connectOptions = new OracleConnectOptions()
.setPort(1521)
.setHost("the-host")
.setDatabase("the-db")
.setUser("user")
.setPassword("secret");
// Pool Options
PoolOptions poolOptions = new PoolOptions().setMaxSize(5);
// Create the pool from the data object
Pool pool = OracleBuilder.pool()
.with(poolOptions)
.connectingTo(connectOptions)
.using(vertx)
.build();
pool
.getConnection()
.onComplete(ar -> {
// Handling your connection
});
Connection URI
Apart from configuring with a OracleConnectOptions
data object, we also provide you with an alternative way to connect when you want to configure with a connection URI.
Using the EZConnect format:
String connectionUri = "oracle:thin:@mydbhost1:5521/mydbservice?connect_timeout=10sec";
// Connect options
OracleConnectOptions connectOptions = OracleConnectOptions.fromUri(connectionUri)
.setUser("user")
.setPassword("secret");
// Pool Options
PoolOptions poolOptions = new PoolOptions().setMaxSize(5);
// Create the pool from the connection URI
Pool pool = OracleBuilder.pool()
.with(poolOptions)
.connectingTo(connectOptions)
.using(vertx)
.build();
Or, using the TNS Alias format:
String connectionUri = "oracle:thin:@prod_db?TNS_ADMIN=/work/tns/";
// Connect options
OracleConnectOptions connectOptions = OracleConnectOptions.fromUri(connectionUri)
.setUser("user")
.setPassword("secret");
// Pool Options
PoolOptions poolOptions = new PoolOptions().setMaxSize(5);
// Create the pool from the connection URI
Pool pool = OracleBuilder.pool()
.with(poolOptions)
.connectingTo(connectOptions)
.using(vertx)
.build();
Connect retries
You can configure the client to retry when a connection fails to be established.
options
.setReconnectAttempts(2)
.setReconnectInterval(1000);
Running queries
When you don’t need a transaction or run single queries, you can run queries directly on the pool; the pool will use one of its connection to run the query and return the result to you.
Here is how to run simple queries:
client
.query("SELECT * FROM users WHERE id='julien'")
.execute()
.onComplete(ar -> {
if (ar.succeeded()) {
RowSet<Row> result = ar.result();
System.out.println("Got " + result.size() + " rows ");
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
});
Prepared queries
You can do the same with prepared queries.
The SQL string can refer to parameters by position, using the database syntax `?`
client
.preparedQuery("SELECT * FROM users WHERE id=?")
.execute(Tuple.of("julien"))
.onComplete(ar -> {
if (ar.succeeded()) {
RowSet<Row> rows = ar.result();
System.out.println("Got " + rows.size() + " rows ");
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
});
Query methods provides an asynchronous RowSet
instance that works for SELECT queries
client
.preparedQuery("SELECT first_name, last_name FROM users")
.execute()
.onComplete(ar -> {
if (ar.succeeded()) {
RowSet<Row> rows = ar.result();
for (Row row : rows) {
System.out.println("User " + row.getString(0) + " " + row.getString(1));
}
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
});
or UPDATE/INSERT queries:
client
.preparedQuery("INSERT INTO users (first_name, last_name) VALUES (?, ?)")
.execute(Tuple.of("Julien", "Viet"))
.onComplete(ar -> {
if (ar.succeeded()) {
RowSet<Row> rows = ar.result();
System.out.println(rows.rowCount());
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
});
The Row
gives you access to your data by index
System.out.println("User " + row.getString(0) + " " + row.getString(1));
Caution
|
Column indexes start at 0, not at 1. |
Alternatively, data can be retrieved by name:
System.out.println("User " + row.getString("first_name") + " " + row.getString("last_name"));
The client will not do any magic here and the column name is identified with the name in the table regardless of how your SQL text is.
You can access a wide variety of of types
String firstName = row.getString("first_name");
Boolean male = row.getBoolean("male");
Integer age = row.getInteger("age");
You can use cached prepared statements to execute one-shot prepared queries:
connectOptions.setCachePreparedStatements(true);
client
.preparedQuery("SELECT * FROM users WHERE id = ?")
.execute(Tuple.of("julien"))
.onComplete(ar -> {
if (ar.succeeded()) {
RowSet<Row> rows = ar.result();
System.out.println("Got " + rows.size() + " rows ");
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
});
You can create a PreparedStatement
and manage the lifecycle by yourself.
sqlConnection
.prepare("SELECT * FROM users WHERE id = ?")
.onComplete(ar -> {
if (ar.succeeded()) {
PreparedStatement preparedStatement = ar.result();
preparedStatement.query()
.execute(Tuple.of("julien"))
.onComplete(ar2 -> {
if (ar2.succeeded()) {
RowSet<Row> rows = ar2.result();
System.out.println("Got " + rows.size() + " rows ");
preparedStatement.close();
} else {
System.out.println("Failure: " + ar2.cause().getMessage());
}
});
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
});
Batches
You can execute prepared batch
List<Tuple> batch = new ArrayList<>();
batch.add(Tuple.of("julien", "Julien Viet"));
batch.add(Tuple.of("emad", "Emad Alblueshi"));
// Execute the prepared batch
client
.preparedQuery("INSERT INTO USERS (id, name) VALUES (?, ?)")
.executeBatch(batch)
.onComplete(res -> {
if (res.succeeded()) {
// Process rows
RowSet<Row> rows = res.result();
} else {
System.out.println("Batch failed " + res.cause());
}
});
Retrieving generated key values
When executing INSERT
queries, you can retrieve the generated key values.
The values are returned as a Row
instance.
This instance is accessible by invoking SqlResult.property(kind)
using the OracleClient.GENERATED_KEYS
property kind.
The key values can be retrieved by column name:
String sql = "INSERT INTO EntityWithIdentity (name, position) VALUES (?, ?)";
// Retrieve generated key column value by name
OraclePrepareOptions options = new OraclePrepareOptions()
.setAutoGeneratedKeysIndexes(new JsonArray().add("ID"));
client.preparedQuery(sql, options)
.execute(Tuple.of("john", 3))
.onComplete(ar -> {
if (ar.succeeded()) {
RowSet<Row> result = ar.result();
Row generated = result.property(OracleClient.GENERATED_KEYS);
Long id = generated.getLong("ID");
}
});
Or, they can be retrieved by column index:
String sql = "INSERT INTO EntityWithIdentity (name, position) VALUES (?, ?)";
// Retrieve generated key column value by index
OraclePrepareOptions options = new OraclePrepareOptions()
.setAutoGeneratedKeysIndexes(new JsonArray().add("1"));
client.preparedQuery(sql, options)
.execute(Tuple.of("john", 3))
.onComplete(ar -> {
if (ar.succeeded()) {
RowSet<Row> result = ar.result();
Row generated = result.property(OracleClient.GENERATED_KEYS);
Long id = generated.getLong("ID");
}
});
Using connections
Getting a connection
When you need to execute sequential queries (without a transaction), you can create a new connection or borrow one from the pool. Remember that between acquiring the connection from the pool and returning it to the pool, you should take care of the connection because it might be closed by the server for some reason such as an idle time out.
pool
.getConnection()
.compose(connection ->
connection
.preparedQuery("INSERT INTO Users (first_name,last_name) VALUES (?, ?)")
.executeBatch(Arrays.asList(
Tuple.of("Julien", "Viet"),
Tuple.of("Emad", "Alblueshi")
))
.compose(res -> connection
// Do something with rows
.query("SELECT COUNT(*) FROM Users")
.execute()
.map(rows -> rows.iterator().next().getInteger(0)))
// Return the connection to the pool
.eventually(v -> connection.close())
).onSuccess(count -> {
System.out.println("Insert users, now the number of users is " + count);
});
Prepared queries can be created:
connection
.prepare("SELECT * FROM users WHERE first_name LIKE ?")
.compose(pq ->
pq.query()
.execute(Tuple.of("Julien"))
.eventually(v -> pq.close())
).onSuccess(rows -> {
// All rows
});
Simplified connection API
When you use a pool, you can call withConnection
to pass it a function executed
within a connection.
It borrows a connection from the pool and calls the function with this connection.
The function must return a future of an arbitrary result.
After the future completes, the connection is returned to the pool and the overall result is provided.
pool.withConnection(connection ->
connection
.preparedQuery("INSERT INTO Users (first_name,last_name) VALUES (?, ?)")
.executeBatch(Arrays.asList(
Tuple.of("Julien", "Viet"),
Tuple.of("Emad", "Alblueshi")
))
.compose(res -> connection
// Do something with rows
.query("SELECT COUNT(*) FROM Users")
.execute()
.map(rows -> rows.iterator().next().getInteger(0)))
).onSuccess(count -> {
System.out.println("Insert users, now the number of users is " + count);
});
Using transactions
Transactions with connections
You can execute transaction using SQL BEGIN
/COMMIT
/ROLLBACK
, if you do so you must use
a SqlConnection
and manage it yourself.
Or you can use the transaction API of SqlConnection
:
pool.getConnection()
// Transaction must use a connection
.onSuccess(conn -> {
// Begin the transaction
conn.begin()
.compose(tx -> conn
// Various statements
.query("INSERT INTO Users (first_name,last_name) VALUES ('Julien','Viet')")
.execute()
.compose(res2 -> conn
.query("INSERT INTO Users (first_name,last_name) VALUES ('Emad','Alblueshi')")
.execute())
// Commit the transaction
.compose(res3 -> tx.commit()))
// Return the connection to the pool
.eventually(v -> conn.close())
.onSuccess(v -> System.out.println("Transaction succeeded"))
.onFailure(err -> System.out.println("Transaction failed: " + err.getMessage()));
});
When the database server reports the current transaction is failed (e.g the infamous current transaction is aborted, commands ignored until
end of transaction block), the transaction is rollbacked and the completion
future
is failed with a TransactionRollbackException
:
tx.completion()
.onFailure(err -> {
System.out.println("Transaction failed => rolled back");
});
Simplified transaction API
When you use a pool, you can call withTransaction
to pass it a function executed
within a transaction.
It borrows a connection from the pool, begins the transaction and calls the function with a client executing all operations in the scope of this transaction.
The function must return a future of an arbitrary result:
-
when the future succeeds the client will commit the transaction
-
when the future fails the client will rollback the transaction
After the transaction completes, the connection is returned to the pool and the overall result is provided.
pool.withTransaction(client -> client
.query("INSERT INTO Users (first_name,last_name) VALUES ('Julien','Viet')")
.execute()
.flatMap(res -> client
.query("INSERT INTO Users (first_name,last_name) VALUES ('Emad','Alblueshi')")
.execute()
// Map to a message result
.map("Users inserted")))
.onSuccess(v -> System.out.println("Transaction succeeded"))
.onFailure(err -> System.out.println("Transaction failed: " + err.getMessage()));
Cursors and streaming
By default, prepared query execution fetches all rows, you can use a
Cursor
to control the amount of rows you want to read:
connection
.prepare("SELECT * FROM users WHERE age > ?")
.onComplete(ar1 -> {
if (ar1.succeeded()) {
PreparedStatement pq = ar1.result();
// Create a cursor
Cursor cursor = pq.cursor(Tuple.of(18));
// Read 50 rows
cursor
.read(50)
.onComplete(ar2 -> {
if (ar2.succeeded()) {
RowSet<Row> rows = ar2.result();
// Check for more ?
if (cursor.hasMore()) {
// Repeat the process...
} else {
// No more rows - close the cursor
cursor.close();
}
}
});
}
});
Cursors shall be closed when they are released prematurely:
cursor
.read(50)
.onComplete(ar2 -> {
if (ar2.succeeded()) {
// Close the cursor
cursor.close();
}
});
A stream API is also available for cursors, which can be more convenient, specially with the Rxified version.
connection
.prepare("SELECT * FROM users WHERE age > ?")
.onComplete(ar1 -> {
if (ar1.succeeded()) {
PreparedStatement pq = ar1.result();
// Fetch 50 rows at a time
RowStream<Row> stream = pq.createStream(50, Tuple.of(18));
// Use the stream
stream.exceptionHandler(err -> {
System.out.println("Error: " + err.getMessage());
});
stream.endHandler(v -> {
System.out.println("End of stream");
});
stream.handler(row -> {
System.out.println("User: " + row.getString("last_name"));
});
}
});
The stream read the rows by batch of 50
and stream them, when the rows have been passed to the handler,
a new batch of 50
is read and so on.
The stream can be resumed or paused, the loaded rows will remain in memory until they are delivered and the cursor will stop iterating.
Data types supported
Currently, the client supports the following Oracle data types:
-
CHAR/VARCHAR2(
java.lang.String
) -
NCHAR/NVARCHAR2(
java.lang.String
) -
NUMBER(
BigDecimal
) -
FLOAT(
java.lang.Double
) -
DATE(
java.time.LocalDate
) -
TIMESTAMP(
java.time.LocalDateTime
) -
RAW(
io.vertx.core.buffer.Buffer
)
Tuple decoding uses the above types when storing values.
BLOB
data type is also supported with one caveat: it must be represented by an instance of Blob
when writing or filtering.
However, when reading BLOB
data, the client returns a Buffer
.
client.preparedQuery("INSERT INTO images (name, data) VALUES (?, ?)")
// Use io.vertx.oracleclient.data.Blob when inserting
.execute(Tuple.of("beautiful-sunset.jpg", Blob.copy(imageBuffer)))
.onComplete(ar -> {
// Do something
});
client.preparedQuery("SELECT data FROM images WHERE id = ?")
.execute(Tuple.of(id))
.onComplete(ar -> {
if (ar.succeeded()) {
Row row = ar.result().iterator().next();
// Use io.vertx.core.buffer.Buffer when reading
Buffer data = row.getBuffer("data");
}
});
Tracing queries
The SQL client can trace query execution when Vert.x has tracing enabled.
The client reports the following client spans:
-
Query
operation name -
tags
-
db.system
: the database management system product -
db.user
: the database username -
db.instance
: the database instance -
db.statement
: the SQL query -
db.type
: sql
The default tracing policy is PROPAGATE
, the client
will only create a span when involved in an active trace.
You can change the client policy with setTracingPolicy
,
e.g you can set ALWAYS
to always report
a span:
options.setTracingPolicy(TracingPolicy.ALWAYS);
Collector queries
You can use Java collectors with the query API:
Collector<Row, ?, Map<Long, String>> collector = Collectors.toMap(
row -> row.getLong("id"),
row -> row.getString("last_name"));
// Run the query with the collector
client.query("SELECT * FROM users")
.collecting(collector)
.execute()
.onComplete(ar -> {
if (ar.succeeded()) {
SqlResult<Map<Long, String>> result = ar.result();
// Get the map created by the collector
Map<Long, String> map = result.value();
System.out.println("Got " + map);
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
});
The collector processing must not keep a reference on the Row
as there is a single row used for processing the entire set.
The Java Collectors
provides many interesting predefined collectors, for example you can create easily create a string directly from the row set:
Collector<Row, ?, String> collector = Collectors.mapping(
row -> row.getString("last_name"),
Collectors.joining(",", "(", ")")
);
// Run the query with the collector
client.query("SELECT * FROM users")
.collecting(collector)
.execute()
.onComplete(ar -> {
if (ar.succeeded()) {
SqlResult<String> result = ar.result();
// Get the string created by the collector
String list = result.value();
System.out.println("Got " + list);
} else {
System.out.println("Failure: " + ar.cause().getMessage());
}
});
Using SSL/TLS
To enable encryption in client options, use the setSsl
method.
By default, ssl
is set to false
.
oracleConnectOptions.setSsl(true);
Encryption can be customized using properties. For example, to set a trust store:
oracleConnectOptions
.setSsl(true)
.addProperty("javax.net.ssl.trustStore", pathToTrustStore)
.addProperty("javax.net.ssl.trustStoreType", "JKS")
.addProperty("javax.net.ssl.trustStorePassword", trustStorePassword);