关于hibernateTemplate空指针

zanchuanyi2540 2017-08-14 09:47:25



//测试类

public class test extends BaseDaoImpl<Question> {

	@Test

	public void fun1(){

		Question q=new Question();

		q.setQst_id(5);

		q.setQst_A("dasdsadas");

		System.out.println(q.toString());

		super.save(q);

	}

}

异常：
java.lang.NullPointerException
at com.itheima.bos.dao.base.impl.BaseDaoImpl.save(BaseDaoImpl.java:38)
at test.fun1(test.java:14)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:45)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:42)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)



public class BaseDaoImpl<T> extends HibernateDaoSupport implements IBaseDao<T> {

	//代表的是某个实体的类型

	private Class<T> entityClass;	

	@Resource//根据类型注入spring工厂中的会话工厂对象sessionFactory

	public void setMySessionFactory(SessionFactory sessionFactory){

		super.setSessionFactory(sessionFactory);

	}	



	//在父类（BaseDaoImpl）的构造方法中动态获得entityClass

	public BaseDaoImpl() {

		ParameterizedType superclass = (ParameterizedType) this.getClass().getGenericSuperclass();

		//获得父类上声明的泛型数组

		Type[] actualTypeArguments = superclass.getActualTypeArguments();

		entityClass = (Class<T>) actualTypeArguments[0];

	}

	public void save(T entity) {

		this.getHibernateTemplate().save(entity);

	}

	

	public void delete(T entity) {

		this.getHibernateTemplate().delete(entity);

	}

spring配置hibernate



<!-- 配置LocalSessionFactoryBean，spring提供的用于整合hibernate的工厂bean -->

	<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">

		<property name="dataSource" ref="dataSource"/>

		<!-- 注入hibernate相关的属性配置 -->

		<property name="hibernateProperties">

			<props>

				<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>

				<prop key="hibernate.hbm2ddl.auto">update</prop>

				<prop key="hibernate.show_sql">true</prop>

				<prop key="hibernate.format_sql">true</prop>

			</props>

		</property>

		<!-- 注入hibernate的映射文件 -->

		<property name="mappingLocations">

			<list>

				<value>classpath:com/itheima/bos/domain/*.xml</value>

			</list>

		</property>

	</bean>

	

	<!-- 配置事务管理器 -->

	<bean id="transactionManager" class="org.springframework.orm.hibernate5.HibernateTransactionManager">

		<property name="sessionFactory" ref="sessionFactory"/>

	</bean>

实体类



package cn.itcast.domain;



import java.util.HashSet;

import java.util.Set;



public class Question {

   private int qst_id;

   private String qst_name;//题目名称

   private String qst_type;//题目类型

   private String qst_score;//题目分值

   private String qst_A;//A选项

   private String qst_B;//B选项

   private String qst_C;//C选项

   private String qst_D;//D选项

   private String qst_answer;//答案

   private Set<Paper> paper=new HashSet<>();





@Override

public String toString() {

	return "Question [qst_id=" + qst_id + ", qst_name=" + qst_name + ", qst_type=" + qst_type + ", qst_score="

			+ qst_score + ", qst_A=" + qst_A + ", qst_B=" + qst_B + ", qst_C=" + qst_C + ", qst_D=" + qst_D

			+ ", qst_answer=" + qst_answer + ", paper=" + paper + "]";

}

public Question() {

	super();

	// TODO Auto-generated constructor stub

}

public Question( String qst_name, String qst_type, String qst_score, String qst_A, String qst_B,

		String qst_C, String qst_D, String qst_answer) {

	super();

	

	this.qst_name = qst_name;

	this.qst_type = qst_type;

	this.qst_score = qst_score;

	this.qst_A = qst_A;

	this.qst_B = qst_B;

	this.qst_C = qst_C;

	this.qst_D = qst_D;

	this.qst_answer = qst_answer;

	

}

public int getQst_id() {

	return qst_id;

}

public void setQst_id(int qst_id) {

	this.qst_id = qst_id;

}

public String getQst_name() {

	return qst_name;

}

public void setQst_name(String qst_name) {

	this.qst_name = qst_name;

}

public String getQst_type() {

	return qst_type;

}

public void setQst_type(String qst_type) {

	this.qst_type = qst_type;

}

public String getQst_score() {

	return qst_score;

}

public void setQst_score(String qst_score) {

	this.qst_score = qst_score;

}

public String getQst_A() {

	return qst_A;

}

public void setQst_A(String qst_A) {

	this.qst_A = qst_A;

}

public String getQst_B() {

	return qst_B;

}

public void setQst_B(String qst_B) {

	this.qst_B = qst_B;

}

public String getQst_C() {

	return qst_C;

}

public void setQst_C(String qst_C) {

	this.qst_C = qst_C;

}

public String getQst_D() {

	return qst_D;

}

public void setQst_D(String qst_D) {

	this.qst_D = qst_D;

}

public String getQst_answer() {

	return qst_answer;

}

public void setQst_answer(String qst_answer) {

	this.qst_answer = qst_answer;

}

public Set<Paper> getPaper() {

	return paper;

}

public void setPaper(Set<Paper> paper) {

	this.paper = paper;

}

   

}

hibernate



<?xml version="1.0" encoding="UTF-8"?>

<!DOCTYPE hibernate-mapping PUBLIC 

    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"

    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

  

<hibernate-mapping package="cn.itcast.domain" >

	<class name="Question" table="exam_question" >



		<id name="qst_id"  type="java.lang.Integer">

			<!-- generator:主键生成策略(明天讲) -->

			<generator class="native"></generator>

		</id>

		

		<property name="qst_name"  >

		</property>

		<property name="qst_type"  ></property>

		<property name="qst_score"  ></property>

		<property name="qst_A"  ></property>

		<property name="qst_B" ></property>

		<property name="qst_C"  ></property>

		<property name="qst_D"  ></property>

		<property name="qst_answer"  ></property>

		<!-- 多对多 -->

		<set name="paper" table="exam_paper_question">

		   <key column="qst_id"></key>

		   <many-to-many class="Paper" column="pap_id"></many-to-many>

		</set>

	</class>

</hibernate-mapping>