级联保存的时候
出现java.lang.NullPointerException
selectCourse.setStudentInfo(studentInfo);//从此处开始出错
也就是说根本没保存进去，
System.out.println("学号：" + getSelectSnu() + "教师编号："
+ getSelectTearcher() + "课程编号:" + getSelect1Course());
这个几个的值已经全部获得了的。
POJO：
- Java code
public class SelectCourse implements java.io.Serializable { // Fields private String snu; private TearcherInfo tearcherInfo; private StudentInfo studentInfo; private CouresInfo couresInfo; private String ctime; private Integer cgrade;/*get、set方法省略*/Action：
- Java code
public String addSelectCourse() throws Exception { TearcherInfo tearcherInfo = new TearcherInfo(); StudentInfo studentInfo = new StudentInfo(); CouresInfo couresInfo = new CouresInfo(); System.out.println("学号：" + getSelectSnu() + "教师编号：" + getSelectTearcher() + "课程编号:" + getSelect1Course()); tearcherInfo.setTnu(getSelectTearcher()); studentInfo.setSnu(getSelectSnu()); couresInfo.setCnu(getSelect1Course()); selectCourse.setStudentInfo(studentInfo);//从此处开始出错！java.lang.NullPointerException selectCourse.setCouresInfo(couresInfo); selectCourse.setTearcherInfo(tearcherInfo); selectCourse.setCgrade(getCgrade()); selectCourse.setCtime(getCtime()); try { adm.saveSelectCourse(selectCourse); } catch (Exception e) { return "input"; } return "success"; }配置文件：
- XML code
<hibernate-mapping> <class name="com.yaxing.domain.SelectCourse" table="SelectCourse" schema="dbo" catalog="Student"> <id name="snu" type="java.lang.String"> <column name="Snu" length="16" /> <generator class="assigned" /> </id> <many-to-one name="tearcherInfo" class="com.yaxing.domain.TearcherInfo" fetch="select"> <column name="Tnu" length="10" not-null="true" /> </many-to-one> <many-to-one name="studentInfo" class="com.yaxing.domain.StudentInfo" update="false" insert="false" fetch="select"> <column name="Snu" length="16" not-null="true" unique="true" /> </many-to-one> <many-to-one name="couresInfo" class="com.yaxing.domain.CouresInfo" fetch="select"> <column name="Cnu" length="10" not-null="true" /> </many-to-one> <property name="ctime" type="java.lang.String"> <column name="Ctime" length="10" /> </property> <property name="cgrade" type="java.lang.Integer"> <column name="Cgrade" /> </property> </class></hibernate-mapping>
DAO:
- Java code
public void save(SelectCourse transientInstance) { log.debug("saving SelectCourse instance"); try { getSession().beginTransaction(); getSession().save(transientInstance); log.debug("save successful"); } catch (RuntimeException re) { log.error("save failed", re); throw re; }