ConnectionPooling Configuration while using Spring jdbcTemplate

Question

I am developing an application that needs to call a DB2 function on the mainframe to get an id.

In my spring application context, I have defined my jdbc template to query DB2 on zOS thusly:

    <bean id="jdbcTemplateDB2"
       class="org.springframework.jdbc.core.JdbcTemplate">
         <property name="dataSource" ref="dataSourceDB2"/>
    </bean>

I then define the datasource as follows:

 <bean id="dataSourceDB2" 
    class="com.ibm.db2.jcc.DB2DataSource">
        <property name="serverName" value="hostname" />
        <property name="portNumber" value="portno"/>
        <property name="databaseName" value="dbname"/>
        <property name="driverType" value="4"/>
        <property name="user" value="userid"/>
        <property name="password" value="password"/>
 </bean>

The above works. However, looking inside the ibm's db2jcc.jar files, I see a class for datasource WITH connection pooling - com.ibm.db2.jcc.DB2ConnectionPoolDataSource. So I tried to use that instead of the one above - like so :

 <bean id="dataSourceDB2"
    class="com.ibm.db2.jcc.DB2ConnectionPoolDataSource">
        <property name="serverName" value="hostname" />
        <property name="portNumber" value="portno"/>
        <property name="databaseName" value="dbname"/>
        <property name="driverType" value="4"/>
        <property name="user" value="userid"/>
        <property name="password" value="password"/>
 </bean>

However, using the DB2ConnectionPoolDataSource gives me the following error.

Cannot convert value of type [com.ibm.db2.jcc.DB2ConnectionPoolDataSource] to required type [javax.sql.DataSource] for property 'dataSource': no matching editors or conversion strategy found

The complete stackTrace is below

    Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'classUniqueIdDaoImpl_v2': Injection of resource dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jdbcTemplateDB2' defined in class path resource [META-INF/spring/applicationContext-db2.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'com.ibm.db2.jcc.DB2ConnectionPoolDataSource' to required type 'javax.sql.DataSource' for property 'dataSource'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [com.ibm.db2.jcc.DB2ConnectionPoolDataSource] to required type [javax.sql.DataSource] for property 'dataSource': no matching editors or conversion strategy found
        at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:307)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1106)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:609)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:469)
        at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
        at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
        at com.slma.euclid.core.dao.MainDB2.main(MainDB2.java:18)
    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jdbcTemplateDB2' defined in class path resource [META-INF/spring/applicationContext-db2.xml]: Initialization of bean failed; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'com.ibm.db2.jcc.DB2ConnectionPoolDataSource' to required type 'javax.sql.DataSource' for property 'dataSource'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [com.ibm.db2.jcc.DB2ConnectionPoolDataSource] to required type [javax.sql.DataSource] for property 'dataSource': no matching editors or conversion strategy found
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:527)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:876)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:818)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:735)
        at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.autowireResource(CommonAnnotationBeanPostProcessor.java:439)
        at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.getResource(CommonAnnotationBeanPostProcessor.java:417)
        at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor$ResourceElement.getResourceToInject(CommonAnnotationBeanPostProcessor.java:559)
        at org.springframework.beans.factory.annotation.InjectionMetadata$InjectedElement.inject(InjectionMetadata.java:150)
        at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
        at org.springframework.context.annotation.CommonAnnotationBeanPostProcessor.postProcessPropertyValues(CommonAnnotationBeanPostProcessor.java:304)
        ... 13 more
    Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert property value of type 'com.ibm.db2.jcc.DB2ConnectionPoolDataSource' to required type 'javax.sql.DataSource' for property 'dataSource'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [com.ibm.db2.jcc.DB2ConnectionPoolDataSource] to required type [javax.sql.DataSource] for property 'dataSource': no matching editors or conversion strategy found
        at org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:485)
        at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:516)
        at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:510)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCapableBeanFactory.java:1406)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1365)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1118)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517)
        ... 27 more
    Caused by: java.lang.IllegalStateException: Cannot convert value of type [com.ibm.db2.jcc.DB2ConnectionPoolDataSource] to required type [javax.sql.DataSource] for property 'dataSource': no matching editors or conversion strategy found
        at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:241)
        at org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:470)
        ... 33 more

What am I doing wrong? What is the correct way to use a connection pooled datasource while instantiating the Spring JdbcTemplate?

Any help is appreciated.

-SGB

Answer 1

An annotation based approach with Spring and DB2ConnectionPoolDataSource:

application.properties

spring.datasource.url=jdbc:db2://DBHOST:50000/DB:currentSchema=MYSCHEMA;currentFunctionPath=MYSCHEMA;\
    clientProgramName=APPNAME-MYSCHEMA;\
    progressiveStreaming=2;retrieveMessagesFromServerOnGetMessage=true;fullyMaterializeLobData=true;\
    clientApplcompat=V12R1M500;jdbcCollection=NULLIDV12R1M500;currentPackageSet=NULLIDV12R1M500;
spring.datasource.username=USER
spring.datasource.password=PWD

ApplicationConfig.java

@Configuration
@PropertySource("classpath:application.properties")
public class ApplicationConfig {
    private static final Logger LOGGER = LoggerFactory.getLogger(ApplicationConfig.class);

    @Value("${spring.datasource.url}")
    private String url;

    @Value("${spring.datasource.username}")
    private String username;

    @Value("${spring.datasource.password}")
    private String password;

    @Bean
    public DB2ConnectionPoolDataSource dataSource() {
        LOGGER.info("DATASOURCE: " + url);
        DB2ConnectionPoolDataSource ds = new DB2ConnectionPoolDataSource();
        ds.setDriverType(4);
        Properties hostPortDb = splitUrlHostPortDb(url);
        ds.setServerName(hostPortDb.getProperty("server"));
        ds.setPortNumber(Integer.parseInt(hostPortDb.getProperty("port")));
        ds.setDatabaseName(hostPortDb.getProperty("db"));
        Properties paramValuePairs = splitUrlParamValuePairs(url);
        setParamValuePairs(ds, paramValuePairs);
        ds.setUser(username);
        ds.setPassword(password);
        return ds;
    }

    private Properties splitUrlHostPortDb(String url) {
        Properties properties = new Properties();
        int hostIndex = url.indexOf("//");
        int lastColonIndex = url.lastIndexOf(":");
        String hostPortDb = url.substring(hostIndex, lastColonIndex);
        URI uri = URI.create(hostPortDb);
        properties.put("server", uri.getHost());
        properties.put("port", uri.getPort() + "");
        properties.put("db", uri.getPath().substring(1));
        return properties;
    }

    private Properties splitUrlParamValuePairs(String url) {
        Properties properties = new Properties();
        int lastColonIndex = url.lastIndexOf(":");
        String paramValues = url.substring(lastColonIndex + 1);
        paramValues = paramValues.replaceAll(";", "\n");
        try {
            properties.load(new StringReader(paramValues));
        } catch (IOException ex) {
            String msg = "DATASOURCE: " + paramValues;
            LOGGER.error(msg, ex);
            throw new RuntimeException(msg, ex);
        }
        return properties;
    }

    private void setParamValuePairs(DB2ConnectionPoolDataSource ds, Properties properties) {
        for (Object key : properties.keySet()) {
            String value = (String) properties.get(key);
            setter(ds, (String) key, value);
        }
    }

    private void setter(DB2ConnectionPoolDataSource ds, String key, String value) {
        boolean invoked = false;
        String setterName = "set" + StringUtils.capitalize(key);
        try {
            Method[] methods = DB2ConnectionPoolDataSource.class.getMethods();
            for (Method method : methods) {
                if (method.getName().equals(setterName)) {
                    method.setAccessible(true);
                    if (method.getParameterTypes()[0] == String.class) {
                        method.invoke(ds, value);
                        invoked = true;
                    } else if (method.getParameterTypes()[0] == short.class) {
                        method.invoke(ds, Short.parseShort(value));
                        invoked = true;
                    } else if (method.getParameterTypes()[0] == int.class) {
                        method.invoke(ds, Integer.parseInt(value));
                        invoked = true;
                    } else if (method.getParameterTypes()[0] == long.class) {
                        method.invoke(ds, Long.parseLong(value));
                        invoked = true;
                    } else if (method.getParameterTypes()[0] == boolean.class) {
                        method.invoke(ds, Boolean.parseBoolean(value));
                        invoked = true;
                    }
                    LOGGER.info("DATASOURCE: " + method.getParameterTypes()[0] + " " + method + "=" + value);
                }
            }
        } catch (Exception ex) {
            String msg = "DATASOURCE: Assignment " + setterName + "=" + value + " failure - check type of argument.";
            LOGGER.error(msg, ex);
            throw new RuntimeException(msg, ex);
        }
        if (!invoked) {
            String msg = "DATASOURCE: Method " + setterName + " not found - typo in DB URL.";
            LOGGER.error(msg);
            throw new RuntimeException(msg);
        }
    }

}

Use the DataSource in a Spring Bean:

@Autowired
private DB2ConnectionPoolDataSource dataSource;

And:

connection = dataSource.getPooledConnection().getConnection();

Answer 2

Have you read this one: http://forum.springsource.org/showthread.php?66142-How-to-use-javax-sql-datasource-with-a-ConnectionPoolDataSource

It says com.ibm.db2.jcc.DB2DataSource is already a connection pool if used correctly.