整合ssh使用hibernateTemplate的find方法报空指针？

这是entity类package com.tjw.mysql.model;
import javax.annotation.Generated;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;import org.springframework.stereotype.Component;@Component("admin")
@Entity
public class Admin {
private int id ;
private String name ;
private String password ;
private int grade ;


@Id public int getId() {
return id;
}

public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public int getGrade() {
return grade;
}
public void setGrade(int grade) {
this.grade = grade;
}
}这是实现类package com.tjw.mysql.dao.impl;import java.io.Serializable;
import java.util.HashSet;
import java.util.List;
import java.util.Set;import javax.annotation.Resource;
import javax.jms.Session;import org.hibernate.Query;
import org.springframework.orm.hibernate3.HibernateTemplate;
import org.springframework.stereotype.Component;
import com.tjw.mysql.dao.AdminDAO;
import com.tjw.mysql.model.Admin;@Component("adminDAO")
public class AdminImpl implements AdminDAO{
private HibernateTemplate hibernateTemplate; 
public void doCreate(Admin admin)  {
// TODO Auto-generated method stub
hibernateTemplate.save(admin);
} public boolean doCreateOrdoUpdate(Admin admin) {
// TODO Auto-generated method stub
return false;
} public void doDelete(Admin admin)  {

this.hibernateTemplate.delete(admin); } public void doUpdate(Admin admin) {
// TODO Auto-generated method stub
this.hibernateTemplate.update(admin);
} public List<Admin> findAll(){
// TODO Auto-generated method stub
  List<Admin> list = (List<Admin>)this. hibernateTemplate.find("from Admin");
return list ; 
} public Admin findById(int id) {
// TODO Auto-generated method stub
return null;
} public int getCount() {
// TODO Auto-generated method stub
return 0;
} public HibernateTemplate getHibernateTemplate() {
return hibernateTemplate;
}
@Resource
public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {
this.hibernateTemplate = hibernateTemplate;
}}
这是配置文件<?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:context="http://www.springframework.org/schema/context"
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/context
           http://www.springframework.org/schema/context/spring-context-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">
<context:annotation-config />
<context:component-scan base-package="com.tjw.mysql.model" />
<context:component-scan base-package="com.tjw.mysql.service" />
<context:component-scan base-package="com.tjw.mysql.dao.impl" /> <!-- 
<bean id="dataSource"
class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">


<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost:3306/spring" />
<property name="username" value="root" />
<property name="password" value="bjsxt" />
</bean>
--> <bean
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations">
<value>classpath:jdbc.properties</value>
</property>
</bean> <bean id="dataSource" destroy-method="close"
class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName"
value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
</bean> <bean id="sessionFactory"
class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<!-- 
<property name="annotatedClasses">
<list>
<value>com.bjsxt.model.User</value>
<value>com.bjsxt.model.Log</value>
</list>
</property>
下面是为了表明哪些是被entity注解标识的
 -->
 <property name="packagesToScan">
<list>
<value>com.tjw.mysql.model</value>

</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">
org.hibernate.dialect.MySQLDialect
</prop>
<prop key="hibernate.show_sql">true</prop>
</props>

</property>
</bean> <bean id="txManager"
class="org.springframework.orm.hibernate3.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean> <aop:config>
<aop:pointcut id="bussinessService"
expression="execution(public * com.bjsxt.service..*.*(..))" />
<aop:advisor pointcut-ref="bussinessService"
advice-ref="txAdvice" />
</aop:config> <tx:advice id="txAdvice" transaction-manager="txManager">
<tx:attributes>
<tx:method name="getUser" read-only="true" />
<tx:method name="add*" propagation="REQUIRED"/>
</tx:attributes>
</tx:advice> <bean id="hibernateTemplate" class="org.springframework.orm.hibernate3.HibernateTemplate">
<property name="sessionFactory" ref="sessionFactory"></property>
</bean></beans>简单地这样调用
AdminImpl adminImpl = new AdminImpl();
adminImpl.findAll();
报出异常
java.lang.NullPointerException
at com.tjw.mysql.dao.impl.AdminImpl.findAll(AdminImpl.java:52)
at com.tjw.mysql.model.TestAdmin.testStudent(TestAdmin.java:101)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:38)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)这是为什么呢？我在beans.xml配置文件里不是把sessionFactory和hibernateTemplate都注入了吗怎么还出现空指针的异常呢