zalando-stups / java-sproc-wrapper   3.0.0

MIT License GitHub

Java Stored Procedure Wrapper: Calling PostgreSQL stored procedures from Java


Build Status Coverage Status Javadoc Maven Central License

Library to make PostgreSQL stored procedures(SProcs) available through simple Java "SProcService" interfaces including automatic object serialization and deserialization (using typemapper and convention-over-configuration).

Supports horizontal database sharding (partition/access logic lies within application), easy use of pg_advisory_lock through annotations to ensure single Java node execution, configurable statement timeouts per stored procedure, and PostgreSQL types including enums and hstore.


To use SProcWrapper, add the following lines to your pom.xml:


Type Mapping

SProcWrapper provides an efficient and easy-to-use mechanism for translating values from database to Java objects and vice-versa. It allows us to map not only primitive types, but also complex types (Java domain objects).

Here are some examples!

Using basic types:

public interface CustomerSProcService {
    int registerCustomer(@SProcParam String name, @SProcParam String email);
CREATE FUNCTION register_customer(p_name TEXT, p_email TEXT)
INSERT INTO z_data.customer(c_name, c_email)
VALUES (p_name, p_email)
    LANGUAGE 'sql'

And a complex type:

public interface OrderSProcService {
    List<Order> findOrders(@SProcParam String email);
CREATE FUNCTION find_orders(p_email TEXT,
                            OUT order_id INT,
                            OUT order_date TIMESTAMP,
                            OUT shipping_address ORDER_ADDRESS)
SELECT o_id,
       ROW (oa_street, oa_city, oa_country)::ORDER_ADDRESS
FROM z_data.order
         JOIN z_data.order_address
              ON oa_order_id = o_id
         JOIN z_data.customer
              ON c_id = o_customer_id
WHERE c_email = p_email
    LANGUAGE 'sql'

Please check unit/integration tests for more examples.

The following table shows the mapping between a database type and a Java type:

Database Java Type
smallint int
integer int
bigint long
decimal java.math.BigDecimal
numeric java.math.BigDecimal
real float
double precision double
serial int
bigserial long
varchar java.lang.String
char char
text java.lang.String
timestamp java.sql.Timestamp
timestamptz java.sql.Timestamp
date java.sql.Timestamp
time java.sql.Timestamp
timetz java.sql.Timestamp
boolean boolean
enum java.lang.Enum
array java.util.List / java.util.Set
hstore java.util.Map<java.lang.String, java.lang.String>

Note: SProcwrapper doesn't support functions returning arrays as a single output. If one wants to return a collection, please return a SETOF instead.

Configure global value transformer loader

Global value transformer loader loads global value transformers from the classpath. By default, it searches value transformers in org.zalando package. You can change this behaviour using the environment variable:


or by calling a method:


It is also possible to provide multiple scan packages using ; separator:



  • Java 11
  • To compile, one should use Maven 3.0.0 or above


  • Spring Framework 5.x
  • PostgreSQL JDBC driver ;)
  • Google Guava

See pom.xml for the full list of dependencies.

How to run integration tests

The provided helper script will start a PostgreSQL instance with Docker on port 5432 and run integration tests:


Known issues

  • PostgreSQL JDBC driver does not honor identical type names in different schemas, this may lead to issues if typemapper is used where types are present with equal name in more than one schema (this problem is solved now with the commit 3ca94e64d6322fa91c477200bfb3719deaeac153 to pgjdbc driver);
  • PostgreSQL domains are not supported as for now;
  • PostgreSQL hstore type is mapped from and to Map<String,String>, there is no way to use Map of different types for now;
  • Two different datasources with the same JDBC URL and different search paths might not work properly when we have types with the identical name;
  • SProcWrapper relies on the search path to resolve conflicting types with the same name (right now, we are not checking the schema). If one specifies the schema of the stored procedure's return type, SProcWrapper might end up using the wrong one, because it will use the search_path to resolve the conflict. For more info check test: SimpleIT.testTypeLookupBugWithSchema;
  • For integration with Spring's transaction management use the TransactionAwareDataSourceProxy as the data source injected into the data source provider.


You can find some more information about the SProcWrapper in our various Zalando Technology blog posts:

🚨 Upgrading from 2.x to 3.x? Please be aware that default scanning package for custom objectTransformer has changed from de.zalando to org.zalando.


See contributing guideline.


MIT license. See license file.