Question

Iam trying to pass dynamic argument values i.e username from request using spring ioc.But iam unable to seen username value in userdaoimp.

UserDAOImpl.java

    public class UserDAOImpl implements UserDAO {
    private DataSource dataSource;
    private JdbcTemplate jdbctemplate;
    private String username;


    public void setUsername(String username) {
        this.username = username;
    }

    public DataSource getDataSource() {
        return dataSource;
    }

    public void setDataSource(DataSource dataSource) {
        this.dataSource = dataSource;
        this.jdbctemplate =new JdbcTemplate (dataSource);
    }




    public int getUserListSize() {
        System.out.println("UserDAOImpl::getUserListSize()"+username);
        int count=this.jdbctemplate.queryForInt("SELECT COUNT(*) FROM USER_INFO");
        return count;
    }

   }

epis.dao.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-2.5.xsd"> 



    <bean id="userdao" class="com.epis.dao.UserDAO">
        <property name="dataSource">
            <ref local="dataSource" />
        </property>
                <property name="username"/>
    </bean>
</beans>

UserService

Answer 1

In the XML you can assing properties only to the surrounding bean.

so

will not work, because UserService does not have a filed username and therefor the spring should not start.

You can write it in two different ways:

<bean id="userdao" class="com.epis.dao.UserDAO">
    <property name="dataSource" ref="dataSource" />
    <property name="username" value="aaa"/>
</bean>

<bean  ... class="...UserService">
    <property name="userdao" ref="userdao" />
<bean>

or

<bean  ... class="...UserService">
    <property name="userdao">
        <bean class="com.epis.dao.UserDAO">
            <property name="dataSource" ref="dataSource" />
            <property name="username" value="aaa"/>
         </bean>
    </property>
<bean>

But you can not mix both styles for one property.

---

Form the comment

Actually my requirement is the username value is getting based on other business logic in UserService.This username will be forwarded into userdao constructor.How can I forward that value to userdao.

This is not possible or at least not without a lot of handwritten magic. The reason is simple: The objects descriped in the XML file are created when the application starts, and the values are set while starting.

But in general I think you can achieve your aim with some scoped beans. But I have highly doubt that scoped beans can be used for the database connection.

I highly recommend to ask a new question hat focus on the dynamic requirement with the explanation you gave in the comment of this answer. (but without the bugy xml example) )

@See Spring Reference Chapter 3.5 Bean scopes