hibernate查询是空指针问题？ss2h集成中
实体类：
Cartes.java
public class Cartes implements java.io.Serializable {
// Fields
private String cid;
private String cname;
private Integer type;
private Float price;
private String cremork;
private Set elists = new HashSet(0);
// Constructors
/** default constructor */
public Cartes() {
}
/** minimal constructor */
public Cartes(String cname, Integer type, Float price) {
this.cname = cname;
this.type = type;
this.price = price;
}
/** full constructor */
public Cartes(String cname, Integer type, Float price, String cremork,
Set elists) {
this.cname = cname;
this.type = type;
this.price = price;
this.cremork = cremork;
this.elists = elists;
}
// Property accessors
public String getCid() {
return this.cid;
}
public void setCid(String cid) {
this.cid = cid;
}
public String getCname() {
return this.cname;
}
public void setCname(String cname) {
this.cname = cname;
}
public Integer getType() {
return this.type;
}
public void setType(Integer type) {
this.type = type;
}
public Float getPrice() {
return this.price;
}
public void setPrice(Float price) {
this.price = price;
}
public String getCremork() {
return this.cremork;
}
public void setCremork(String cremork) {
this.cremork = cremork;
}
public Set getElists() {
return this.elists;
}
public void setElists(Set elists) {
this.elists = elists;
}
}
Elist.java
public class Elist implements java.io.Serializable {
// Fields
private String eid;
private Cartes cartes;
private People people;
private Users users;
private Timestamp etime;
private Integer enum_;
// Constructors
/** default constructor */
public Elist() {
}
/** full constructor */
public Elist(Cartes cartes, People people, Users users, Timestamp etime,
Integer enum_) {
this.cartes = cartes;
this.people = people;
this.users = users;
this.etime = etime;
this.enum_ = enum_;
}
// Property accessors
public String getEid() {
return this.eid;
}
public void setEid(String eid) {
this.eid = eid;
}
public Cartes getCartes() {
return this.cartes;
}
public void setCartes(Cartes cartes) {
this.cartes = cartes;
}
public People getPeople() {
return this.people;
}
public void setPeople(People people) {
this.people = people;
}
public Users getUsers() {
return this.users;
}
public void setUsers(Users users) {
this.users = users;
}
public Timestamp getEtime() {
return this.etime;
}
public void setEtime(Timestamp etime) {
this.etime = etime;
}
public Integer getEnum_() {
return this.enum_;
}
public void setEnum_(Integer enum_) {
this.enum_ = enum_;
}
映射文件：
Cartes.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="com.eshop.entity.Cartes" table="cartes" catalog="eshop">
<id name="cid" type="java.lang.String">
<column name="cid" length="10" />
<generator class="native" />
</id>
<property name="cname" type="java.lang.String">
<column name="cname" length="20" not-null="true" />
</property>
<property name="type" type="java.lang.Integer">
<column name="type" not-null="true" />
</property>
<property name="price" type="java.lang.Float">
<column name="price" precision="12" scale="0" not-null="true" />
</property>
<property name="cremork" type="java.lang.String">
<column name="cremork" length="200" />
</property>
<set name="elists" inverse="true">
<key>
<column name="cid" length="10" not-null="true" />
</key>
<one-to-many class="com.eshop.entity.Elist" />
</set>
</class>
</hibernate-mapping>
Elist.hbm.xml
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
<class name="com.eshop.entity.Elist" table="elist" catalog="eshop">
<id name="eid" type="java.lang.String">
<column name="eid" length="20" />
<generator class="native" />
</id>
<many-to-one name="cartes" class="com.eshop.entity.Cartes" fetch="select">
<column name="cid" length="10" not-null="true" />
</many-to-one>
<many-to-one name="people" class="com.eshop.entity.People" fetch="select">
<column name="pid" not-null="true" />
</many-to-one>
<many-to-one name="users" class="com.eshop.entity.Users" fetch="select">
<column name="uid" length="20" not-null="true" />
</many-to-one>
<property name="etime" type="java.sql.Timestamp">
<column name="etime" length="19" not-null="true" />
</property>
<property name="enum_" type="java.lang.Integer">
<column name="enum" not-null="true" />
</property>
</class>
</hibernate-mapping>
实现类：
public class CartesDaoImpl implements CartesDao {
private HibernateTemplate hibernateTemplate;
public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {
this.hibernateTemplate = hibernateTemplate;
}
/**
* 根据类型查询
*/
public List<Cartes> getCartesByType(Integer type) {
String hql ="from Cartes c where c.type="+type;
List<Cartes> list = hibernateTemplate.find(hql);
if(list!=null && list.size()>0){
return list;
}
return null;
}
}
测试类：
public class Test {
/**
* @param args
*/
public static void main(String[] args) {
CartesDao cartesDao = new CartesDaoImpl();
List<Cartes> list = cartesDao.getCartesByType(1);
}
}
运行的异常：
Exception in thread "main" java.lang.NullPointerException
at com.eshop.dao.impl.CartesDaoImpl.getCartesByType(CartesDaoImpl.java:21)
at com.eshop.test.Test.main(Test.java:16)
请高手指导，小弟不胜感激！！！
hibernate 异常 exception 类 测试
[解决办法]
没有初始化HibernateTemplate，所以报了空指针异常
[解决办法]
CartesDao cartesDao = new CartesDaoImpl();
后面调用下setHibernateTemplate
[解决办法]
Exception in thread "main" java.lang.NullPointerException
at com.eshop.dao.impl.CartesDaoImpl.getCartesByType(CartesDaoImpl.java:21)
楼猪要学会看bug
第一行 空指针异常 一般就是没有实例化和注入没有注入进去（非注水猪肉）
第二行 在 eshop文件里的 dao包里的 imp.CartesDaoImpl 里的 getCartesByType方法 也就是说空指针是这里 然后检测你里面的代码 涉及到空指针的也只有···我靠 老大 你代码没贴全啊 记得给分
[解决办法]
