使用Hibernate配置三张表的映射文件，student表，course表和takes表。
其中student表和course表为多对多关系，
takes是中间表(已经提前创建好)包含：S_id,C_id和score，S_id和C_id已经设置为外键和组合主键
测试类：
出现以下报错（在添加多对多关系后才报错，没有添加前测试类正常执行）
org.hibernate.MappingException: Could not get constructor for org.hibernate.persister.entity.SingleTableEntityPersister
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:123)
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:77)
at org.hibernate.metamodel.internal.MetamodelImpl.initialize(MetamodelImpl.java:181)
at org.hibernate.internal.SessionFactoryImpl.<init>(SessionFactoryImpl.java:312)
at org.hibernate.boot.internal.SessionFactoryBuilderImpl.build(SessionFactoryBuilderImpl.java:471)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:728)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:744)
at group55.xin.connect.HibernateInitialize.rebuildSessionFactory(HibernateInitialize.java:40)
at group55.xin.connect.HibernateInitialize.getSession(HibernateInitialize.java:29)
at group55.xin.Dao.CourseDao.selectAllCourse(CourseDao.java:31)
at group55.xintest.CourseTest.CourseTest(CourseTest.java:23)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
Caused by: org.hibernate.HibernateException: Unable to instantiate default tuplizer [org.hibernate.tuple.entity.PojoEntityTuplizer]
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:91)
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructDefaultTuplizer(EntityTuplizerFactory.java:116)
at org.hibernate.tuple.entity.EntityMetamodel.<init>(EntityMetamodel.java:432)
at org.hibernate.persister.entity.AbstractEntityPersister.<init>(AbstractEntityPersister.java:612)
at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:126)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.hibernate.persister.internal.PersisterFactoryImpl.createEntityPersister(PersisterFactoryImpl.java:96)
... 32 more
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at org.hibernate.tuple.entity.EntityTuplizerFactory.constructTuplizer(EntityTuplizerFactory.java:88)
... 41 more
Caused by: org.hibernate.PropertyNotFoundException: Could not locate getter method for property [group55.xin.Entity.Student#courses]
at org.hibernate.internal.util.ReflectHelper.findGetterMethod(ReflectHelper.java:465)
at org.hibernate.property.access.internal.PropertyAccessBasicImpl.<init>(PropertyAccessBasicImpl.java:41)
at org.hibernate.property.access.internal.PropertyAccessStrategyBasicImpl.buildPropertyAccess(PropertyAccessStrategyBasicImpl.java:27)
at org.hibernate.mapping.Property.getGetter(Property.java:311)
at org.hibernate.tuple.entity.PojoEntityTuplizer.buildPropertyGetter(PojoEntityTuplizer.java:193)
at org.hibernate.tuple.entity.AbstractEntityTuplizer.<init>(AbstractEntityTuplizer.java:147)
at org.hibernate.tuple.entity.PojoEntityTuplizer.<init>(PojoEntityTuplizer.java:53)
... 46 more
java.lang.NullPointerException
at group55.xin.Dao.CourseDao.selectAllCourse(CourseDao.java:32)
at group55.xintest.CourseTest.CourseTest(CourseTest.java:23)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:69)
at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235)
at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54)
结构目录：
配置文件：
Student.hbm.xml
Course.hbm.xml
实体类：
Student:
package group55.xin.Entity;
import javax.persistence.criteria.CriteriaBuilder;
import java.util.HashSet;
import java.util.Set;
public class Student {
private Integer s_id;
private String s_name;
private String Dept;
private String Phone;
private String Sex;
private Integer Age;
private String Email;
private String Dormitory;
private Set<Course> courseSet = new HashSet<>();
public Set<Course> getCourseSet() {
return courseSet;
}
public void setCourseSet(Set<Course> courseSet) {
this.courseSet = courseSet;
}
public String getEmail() {
return Email;
}
public void setEmail(String email) {
Email = email;
}
public String getDormitory() {
return Dormitory;
}
public void setDormitory(String dormitory) {
Dormitory = dormitory;
}
public Integer getS_id() {
return s_id;
}
public void setS_id(Integer s_id) {
this.s_id = s_id;
}
public String getS_name() {
return s_name;
}
public void setS_name(String s_name) {
this.s_name = s_name;
}
public String getDept() {
return Dept;
}
public void setDept(String dept) {
Dept = dept;
}
public String getPhone() {
return Phone;
}
public void setPhone(String phone) {
Phone = phone;
}
public String getSex() {
return Sex;
}
public void setSex(String sex) {
Sex = sex;
}
public Integer getAge() {
return Age;
}
public void setAge(Integer age) {
Age = age;
}
@Override
public String toString() {
return "Student{" +
"s_id=" + s_id +
", s_name='" + s_name + '\'' +
", Dept='" + Dept + '\'' +
", Phone='" + Phone + '\'' +
", Sex='" + Sex + '\'' +
", Age=" + Age +
", Email='" + Email + '\'' +
", Dormitory='" + Dormitory + '\'' +
", courseSet=" + courseSet +
'}';
}
Course:
public class Course {
private Integer c_id;
private String c_name;
private Double Score;
private Set<Student> studentSet = new HashSet<>();
public Set<Student> getStudentSet() {
return studentSet;
}
public void setStudentSet(Set<Student> studentSet) {
this.studentSet = studentSet;
}
public Integer getC_id() {
return c_id;
}
public void setC_id(Integer c_id) {
this.c_id = c_id;
}
public String getC_name() {
return c_name;
}
public void setC_name(String c_name) {
this.c_name = c_name;
}
public Double getScore() {
return Score;
}
public void setScore(Double score) {
Score = score;
}
@Override
public String toString() {
return "Course{" +
"c_id=" + c_id +
", c_name='" + c_name + '\'' +
", Score=" + Score +
", studentSet=" + studentSet +
'}';
}
