Exception in thread "main" java.lang.NullPointerException (cannot connect to database)

Hi guys

would you kno what i am missing?

i am just new to spring and i was ask first to connect to the database using bean.
found a helpful tutorial about it but it still seems not working with me.

im getting this error :

would appreciate your help.

Thank you and God Bless

here is my java ..

DashboardDetailsDaoImpl .java

package ph.com.smart.ws.CreditCard.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;

import ph.com.smart.ws.CreditCard.model.CreditCardBean;

public class DashboardDetailsDaoImpl implements DashboardDetailsDao {
	@Autowired
	private DataSource dataSource;

public CreditCardBean dashboardDetails(CreditCardBean bean) {

Connection conn = null;

try {
			conn = dataSource.getConnection();
			// initialContext.lookup(dataSource);

PreparedStatement ps = conn
			.prepareStatement("EXECUTE query_Dashboard_Details#cws");

ResultSet rs = ps.executeQuery();
			while (rs.next()) {
				System.out.println(rs.getString(1) + " " + rs.getString(2)
						+ "<br>");
			}
		} catch (SQLException e) {
			// 
			e.printStackTrace();
		}

return bean;

}

public static void main(String args[]) throws Exception {
	
		DashboardDetailsDaoImpl dashWS = new DashboardDetailsDaoImpl();
		CreditCardBean bean = new CreditCardBean();

bean = dashWS.dashboardDetails(bean);
		System.out.println("strval2: " + bean.getMin());

}

public DataSource getDataSource() {
		return dataSource;
	}

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

now here is the ApplicationContext in which i place the connection in a bean.

ApplicationContext .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" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd" >
	
	
	
	
	<bean id="txManager"
		class="org.springframework.transaction.jta.JtaTransactionManager" />
	
	<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 
		<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
		<property name="url" value="jdbc:oracle:thin:@10.128.54.84:1521:infratst" />
		<property name="username" value="sa" />
		<property name="password" value="pass" />
	</bean>

thanks so much

Ok so this is a stand alone application? I see you are using Spring 2.5? Is that a requirement? If it is not then upgrade to the newest. Currently 3.1.2

This is sufficient

get rid of this

I would use JDBCTemplate you are not gaining any of the advantages of exception translation or other benefits that Spring provides.

You are not bootstrapping your application correctly. @Autowired only happens in Spring managed beans. You are actually not even bootstrapping Spring at all.

Your main method needs to have something more like this.

Also your transaction manager is not going to work outside of a JEE container.

try this:

Also be aware that DriverManagerDataSource is fine for testing but it should not be used in production.

I think you may need to take a few steps back, buy a book or start with some beginner tutorials and work your way up to what you are trying to do here.

You can start with some of the suggestions I gave but you will find there is a lot to learn, so I would start with the basics like dependency injection and then start adding things as your understanding of what Spring is and how it works increases.

Good Luck!

Hi Bill

Thank you for your reply

i admit im not yet familiar with what Spring can truly offer.
so i kind off, find it difficult still, to grasp some functionality.

anyways, i have tried to implement your suggestion like this.

package ph.com.smart.ws.CreditCard.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.sql.DataSource;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import ph.com.smart.ws.CreditCard.model.CreditCardBean;

public class DashboardDetailsDaoImpl implements DashboardDetailsDao {
	@Autowired
	private DataSource dataSource;

public CreditCardBean dashboardDetails(CreditCardBean bean) {

Connection conn = null;

try {
			conn = dataSource.getConnection();
			// initialContext.lookup(dataSource);

PreparedStatement ps = conn
			.prepareStatement("EXECUTE query_Dashboard_Details#cws");

ResultSet rs = ps.executeQuery();
			while (rs.next()) {
				System.out.println(rs.getString(1) + " " + rs.getString(2)
						+ "<br>");
			}
		} catch (SQLException e) {
			// 
			e.printStackTrace();
		}

return bean;

}

public static void main(String args[]) throws Exception {
		//	ListingDao listingDao = (ListingDao) context.getBean("listingDao");
		
		 ApplicationContext context = new ClassPathXmlApplicationContext("Spring.xml");
		DashboardDetailsDaoImpl dashboardDetails = (DashboardDetailsDaoImpl) context.getBean("dashboardDetails");

//DashboardDetailsDaoImpl dashWS = new DashboardDetailsDaoImpl();
		CreditCardBean bean = new CreditCardBean();

bean = dashboardDetails.dashboardDetails(bean);
		System.out.println("strval2: " + bean.getMin());

}

public DataSource getDataSource() {
		return dataSource;
	}

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

then

applicationContext.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" xmlns:p="http://www.springframework.org/schema/p"
	xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
       http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd
       http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">

<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd" >
	
	
	
	
    <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">  
      <property name="dataSource" ref="dataSource"/>  
    </bean>  
	<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 
		<property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
		<property name="url" value="jdbc:oracle:thin:@10.128.54.84:1521:infratst" />
		<property name="username" value="lincviewer" />
		<property name="password" value="lincviewer" />
	</bean>

<bean id="CheckCardMovementService"
		class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
		<property name="transactionManager" ref="txManager" />
		<property name="target" ref="CheckCardMovementServiceTarget" />
		<property name="transactionAttributes">
			<props>
				<prop key="get*">PROPAGATION_REQUIRED</prop>
				<prop key="add*">PROPAGATION_REQUIRED</prop>
				<prop key="update*">PROPAGATION_REQUIRED</prop>
				<prop key="del*">PROPAGATION_REQUIRED</prop>
			</props>
		</property>
	</bean>

fyi applicationContext.xml resides under target/DasboardDetails/WEB-INF

but now im having this error :

09 24, 12 11:58:42 AM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@1a05308: display name [org.springframework.context.support.ClassPathXmlApplicationContext@1a05308]; startup date [Mon Sep 24 11:58:42 SGT 2012]; root of context hierarchy
09 24, 12 11:58:42 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [applicationContext.xml]
Exception in thread "main" org.springframework.beans.factory.BeanDefinitionStoreException: IOException parsing XML document from class path resource [applicationContext.xml]; nested exception is java.io.FileNotFoundException: class path resource [applicationContext.xml] cannot be opened because it does not exist
	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:349)
	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:310)
	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:143)
	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:178)
	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:149)
	at org.springframework.beans.factory.support.AbstractBeanDefinitionReader.loadBeanDefinitions(AbstractBeanDefinitionReader.java:212)
	at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:113)
	at org.springframework.context.support.AbstractXmlApplicationContext.loadBeanDefinitions(AbstractXmlApplicationContext.java:80)
	at org.springframework.context.support.AbstractRefreshableApplicationContext.refreshBeanFactory(AbstractRefreshableApplicationContext.java:123)
	at org.springframework.context.support.AbstractApplicationContext.obtainFreshBeanFactory(AbstractApplicationContext.java:422)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:352)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
	at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
	at ph.com.smart.ws.CreditCard.dao.DashboardDetailsDaoImpl.main(DashboardDetailsDaoImpl.java:48)
Caused by: java.io.FileNotFoundException: class path resource [applicationContext.xml] cannot be opened because it does not exist
	at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:143)
	at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.loadBeanDefinitions(XmlBeanDefinitionReader.java:336)
	... 13 more

would again appreciate your help ..

In the stack trace it says

Caused by: java.io.FileNotFoundException: class path resource [applicationContext.xml] cannot be opened because it does not exist

It is not finding applicationContext.xml.

in the code you posted it looks like you are loading Spring.xml not applicationContext.xml. What is actually the name of the file? Also is the file directly on the class path? i.e src/main/resources? If it is under a subdirectory then you must specify this when you load it.