Spring Beans for Jdbc not working

Question

I spent last night trying to figure this out. I have a HSQLDB server running and I can connect to it using the JDBC driver. The next part of the assignment is to do the same thing but using the Spring framework. I declared my beans, created my DAO classes, and the program does not connect to the server. Since it is our first time using the JdbcTemplate, we are not supposed to do autowiring. Here are the files I have:

JdbcUserDAO

public class JdbcUserDAO extends JdbcDaoSupport
                    implements UserDAO {

    public User getUserWithId(int id) {
        return new User(1,"gamda","test");
    }

    public int howManyUsers() {
        JdbcTemplate test = getJdbcTemplate();
        System.out.println("Got template");

        try {
            getConnection();
            System.out.println("Got connection");   
        } catch (Exception e) {
            System.out.println("Not connecting");
        }


        int result = test.queryForInt("select count from users");
        System.out.println("Query success");
        return result;
    }

}

beans.xml (on the same folder as my .java files, if it makes a difference)

<?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.xsd">

    <bean id="userDAO" class="com.project2.db.JdbcUserDAO">
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <bean id="questionDAO" class="com.project2.db.JdbcQuestionDAO">
        <property name="jdbcTemplate" ref="jdbcTemplate"/>
    </bean>

    <bean id="answerDAO" class="com.project2.db.AnswerDAO">
        <property name="jdbcTemplate" ref="jdbcTemplate"/>
    </bean>

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

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" 
    destroy-method="close">
        <property name="driverClassName" value="org.hsqldb.jdbc.JDBCDriver"/>
        <property name="url" value="jdbc:hsqldb:hsql://localhost/cpsc476;ifexists=true"/>
        <property name="username" value="SA"/>
        <property name="password" value="Passw0rd"/>
    </bean>
</beans>

build.xml for ant:

<project 
    name="DB_Access" 
    default="compile" 
    xmlns:artifact="antlib:org.apache.maven.artifact.ant">

<target name="init">
    <mkdir dir="classes" />
</target>

<target name="clean">
    <delete dir="classes" />
    <delete dir="jar" />
</target>

<target name="compile" depends="init">
    <javac srcdir="src"
           destdir="classes">
        <classpath refid="dependency.classpath" />
    </javac>
</target>

<target name="run" depends="compile">
    <java classname="com.project2.db.ListQuestionsAndAnswers">
        <classpath>
            <path refid="dependency.classpath" />
            <path location="classes/" />
        </classpath>
    </java>
</target>

<target name="jar" depends="compile">
    <mkdir dir="jar" />
    <jar destfile="jar/db.jar" basedir="classes">
        <manifest>
            <attribute name="Main-Class" value="com.project2.db.dbCon" />
        </manifest>
    </jar>
</target>

<artifact:dependencies 
    pathId="dependency.classpath"
    filesetId="dependency.fileset">
    <dependency
        groupId="org.springframework"
        artifactId="spring-jdbc"
        version="3.2.4.RELEASE" />

    <dependency
        groupId="org.springframework"
        artifactId="spring-beans"
        version="3.2.4.RELEASE"/>

    <dependency
        groupId="org.springframework"
        artifactId="spring-context"
        version="3.0.2.RELEASE"/>

    <dependency
        groupId="org.hsqldb"
        artifactId="hsqldb"
        version="2.3.0" />
    <dependency
        groupId="commons-dbcp"
        artifactId="commons-dbcp"
        version="1.4" />
</artifact:dependencies>
</project>

And the test class I'm using: Edited after reading the tutorial provided

public class ListQuestionsAndAnswers {
    public static int main( String[] args ) {

        ApplicationContext appContext = new ClassPathXmlApplicationContext(
        "beans.xml");

        JdbcUserDAO test = (JdbcUserDAO) appContext.getBean("userDAO"); 
        int answer = test.howManyUsers();
        System.out.println(answer);
        return 0;
    }
}

When I do "ant run" this is the output: Edited because it's a new error

 >[java] org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDAO' defined in class path resource [beans.xml]: Initialization of bean failed; nested exception is java.lang.NoSuchFieldError: NULL
 >[java]    at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:194)
 >[java]    at org.apache.tools.ant.taskdefs.Java.run(Java.java:771)
 >[java]    at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:221)
 >[java]    at org.apache.tools.ant.taskdefs.Java.executeJava(Java.java:135)
 >[java]    at org.apache.tools.ant.taskdefs.Java.execute(Java.java:108)
 >[java]    at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:292)
 >[java]    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 >[java]    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
 >[java]    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 >[java]    at java.lang.reflect.Method.invoke(Method.java:606)
 >[java]    at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
 >[java]    at org.apache.tools.ant.Task.perform(Task.java:348)
 >[java]    at org.apache.tools.ant.Target.execute(Target.java:435)
 >[java]    at org.apache.tools.ant.Target.performTasks(Target.java:456)
 >[java]    at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1393)
 >[java]    at org.apache.tools.ant.Project.executeTarget(Project.java:1364)
 >[java]    at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
 >[java]    at org.apache.tools.ant.Project.executeTargets(Project.java:1248)
 >[java]    at org.apache.tools.ant.Main.runBuild(Main.java:851)
 >[java]    at org.apache.tools.ant.Main.startAnt(Main.java:235)
 >[java]    at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
 >[java]    at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)
 >[java] Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userDAO' defined in class path resource [beans.xml]: Initialization of bean failed; nested exception is java.lang.NoSuchFieldError: NULL
 >[java]    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:529)
 >[java]    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
 >[java]    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
 >[java]    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
 >[java]    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
 >[java]    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
 >[java]    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:628)
 >[java]    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:872)
 >[java]    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:423)
 >[java]    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
 >[java]    at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)
 >[java]    at com.project2.db.ListQuestionsAndAnswers.main(Unknown Source)
 >[java]    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 >[java]    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
 >[java]    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 >[java]    at java.lang.reflect.Method.invoke(Method.java:606)
 >[java]    at org.apache.tools.ant.taskdefs.ExecuteJava.run(ExecuteJava.java:217)
 >[java]    at org.apache.tools.ant.taskdefs.ExecuteJava.execute(ExecuteJava.java:152)
 >[java]    ... 21 more
 >[java] Caused by: java.lang.NoSuchFieldError: NULL
 >[java]    at org.springframework.expression.TypedValue.<clinit>(TypedValue.java:31)
 >[java]    at org.springframework.expression.spel.support.StandardEvaluationContext.setRootObject(StandardEvaluationContext.java:82)
 >[java]    at org.springframework.expression.spel.support.StandardEvaluationContext.<init>(StandardEvaluationContext.java:71)
 >[java]    at org.springframework.context.expression.StandardBeanExpressionResolver.evaluate(StandardBeanExpressionResolver.java:124)
 >[java]    at org.springframework.beans.factory.support.AbstractBeanFactory.evaluateBeanDefinitionString(AbstractBeanFactory.java:1312)
 >[java]    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.evaluate(BeanDefinitionValueResolver.java:225)
 >[java]    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveReference(BeanDefinitionValueResolver.java:312)
 >[java]    at org.springframework.beans.factory.support.BeanDefinitionValueResolver.resolveValueIfNecessary(BeanDefinitionValueResolver.java:107)
 >[java]    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1387)
 >[java]    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1128)
 >[java]    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
 >[java]    ... 38 more
 >[java] Java Result: -1  

So I know my JdbcTemplate is not null, but it fails to connect to the database and I don't know how to check the connection or make it connect.

Answer 1

You have defined JdbcUserDAO as a spring bean with id userDAO, but you are creating instance of it with new operator which won't take care of its dependencies

You need to initialize spring bean context and then fetch the bean from context

• See the basic hello world turorial