当我尝试在数据库中获取项目时，我得到一个错误，即预订未被映射 我尝试了所有尝试将@Entity放在最顶层和@MappedSuperclass，但没有真正起作用
这是错误：
SEVERE: Servlet.service() for servlet [be.pxl.tafelboeker.servlets.ConfirmServlet] in context with path [/HerexamensOef] threw exception
java.lang.IllegalArgumentException: org.hibernate.hql.internal.ast.QuerySyntaxException: booking is not mapped [select b from booking as b where (b.dag=?1 AND b.uur =?2) ]
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:131)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:155)
at org.hibernate.internal.ExceptionConverterImpl.convert(ExceptionConverterImpl.java:162)
at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:636)
at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:23)
at be.pxl.tafelboeker.dao.BoekingDAO.isTafelBeschikbaar(BoekingDAO.java:44)
at be.pxl.tafelboeker.services.BoekingService.isTafelBeschikbaar(BoekingService.java:28)
at be.pxl.tafelboeker.services.BoekingService.boekTafel(BoekingService.java:34)
at be.pxl.tafelboeker.servlets.ConfirmServlet.doPost(ConfirmServlet.java:59)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:212)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:522)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1095)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:672)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1502)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1458)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Unknown Source)
Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: booking is not mapped [select b from booking as b where (b.dag=?1 AND b.uur =?2) ]
at org.hibernate.hql.internal.ast.QuerySyntaxException.generateQueryException(QuerySyntaxException.java:79)
at org.hibernate.QueryException.wrapWithQueryString(QueryException.java:103)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:218)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:142)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:115)
at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:77)
at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:152)
at org.hibernate.internal.AbstractSharedSessionContract.getQueryPlan(AbstractSharedSessionContract.java:526)
at org.hibernate.internal.AbstractSharedSessionContract.createQuery(AbstractSharedSessionContract.java:628)
... 28 more
Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: booking is not mapped
at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:171)
at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:91)
at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:79)
at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:321)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3690)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3579)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:718)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:574)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:311)
at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:259)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:262)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:190)
... 34 more
这里有一些文件
的预订
package be.pxl.tafelboeker.domain;
import java.io.Serializable;
import java.time.LocalDate;
import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Inheritance;
import javax.persistence.MappedSuperclass;
import javax.persistence.Table;
@Table(name="booking")
public class Boeking implements Serializable {
@Id
@Column(name="id")
@GeneratedValue
private int id;
@Column(name="naam")
private String naam;
@Column(name="straat")
private String straat;
@Column(name="stad")
private String stad;
@Column(name="uur")
private Integer uur;
@Column(name="dag")
private LocalDate dag;
public Boeking(){
}
public String getStraat() {
return straat;
}
public void setStraat(String straat) {
this.straat = straat;
}
public String getStad() {
return stad;
}
public void setStad(String stad) {
this.stad = stad;
}
public String getNaam() {
return naam;
}
public void setNaam(String naam) {
this.naam = naam;
}
public Integer getUur() {
return uur;
}
public void setUur(Integer uur) {
this.uur = uur;
}
public LocalDate getDag() {
return dag;
}
public void setDag(LocalDate dag){
this.dag = dag;
}
}
持久性
<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd"
version="2.1">
<persistence-unit name="booking" transaction-type="RESOURCE_LOCAL">
<properties>
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost/booking" />
<property name="javax.persistence.jdbc.user" value="root" />
<property name="javax.persistence.jdbc.password" value="" />
<property name="javax.persistence.schema-generation.database.action"
value="none" />
<!-- Hibernate specific -->
<property name="hibernate.show_sql" value="true" />
</properties>
</persistence-unit>
</persistence>
的pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>be.pxl</groupId>
<artifactId>HerexamensOef</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>HerexamensOef Maven Webapp</name>
<url>http://maven.apache.org</url>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-web-api</artifactId>
<version>7.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>javax.persistence</groupId>
<artifactId>persistence-api</artifactId>
<version>1.0.2</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>5.2.2.Final</version>
</dependency>
</dependencies>
<build>
<finalName>HerexamensOef</finalName>
</build>
</project>
Boeking DAO
package be.pxl.tafelboeker.dao;
import be.pxl.tafelboeker.domain.Boeking;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityManager;
import javax.persistence.Persistence;
import javax.persistence.Query;
import java.time.LocalDate;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
public class BoekingDAO {
private String url;
private String user;
private String password;
EntityManagerFactory emf;
public BoekingDAO(String url, String user, String password) {
this.url = url;
this.user = user;
this.password = password;
}
public void setDriver(String driver)
throws ClassNotFoundException {
Class.forName("com.mysql.jdbc.Driver");
}
private EntityManager getEntityManager() {
emf = Persistence.createEntityManagerFactory("booking");
EntityManager em = emf.createEntityManager();
return em;
}
// TIP : Gebruik TemporalType.DATE voor je query parameter
public boolean isTafelBeschikbaar(LocalDate dag, int uur) {
EntityManager em = getEntityManager();
Query q1 = em.createQuery("select b from booking as b where (b.dag=?1 AND b.uur =?2) ");
q1.setParameter(1, dag);
q1.setParameter(2, uur);
if (q1.getMaxResults() == 0) {
return true;
} else {
return false;
}
}
public void boekTafel(Boeking bean) {
EntityManager em = getEntityManager();
em.persist(bean);
em.close();
emf.close();
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getUser() {
return user;
}
public void setUser(String user) {
this.user = user;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
DriverLoader
package be.pxl.tafelboeker.dao;
public class DriverLoader {
static{
System.out.print("loading database");
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
System.out.println("nope");
e.printStackTrace();
}
}
}