问题描述

SSH整合，hibernate注解配置，无hbm.xml，映射出现问题

java实体类代码：

 package cn.com.car.base.entity;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

import org.hibernate.annotations.GenericGenerator;

@Entity
@Table(name="T_CAR")
public class Car implements Serializable{
    private static final long serialVersionUID = 1L;

    @GenericGenerator(name = "generator", strategy = "guid")
    @Id
    @GeneratedValue(generator = "generator")
    @Column(name = "id", unique = true, nullable = false, length = 38)
    private String id;

    @Column(name="models")
    private String models;//具体车型

    @Column(name="type")
    private String type;//所属类别

    @Column(name="price")
    private int price;//价格

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getModels() {
        return models;
    }

    public void setModels(String models) {
        this.models = models;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Car [id=" + id + ", models=" + models + ", type=" + type
                + ", price=" + price + "]";
    }

}

---

application.xml配置

 <?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
           http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd
           http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd"
       default-autowire="byName" default-lazy-init="true">

    <!-- 属性文件读入 -->
    <bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <list>
                <value>classpath*:hibernate.properties</value>
            </list>
        </property>
    </bean>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${hibernate.connection.driverClassName}"/>
        <property name="url" value="${hibernate.connection.url}"/>
        <property name="username" value="${hibernate.connection.username}"/>
        <property name="password" value="${hibernate.connection.password}"/>
    </bean>

    <!--Hibernate SessionFatory-->
    <bean id="sessionFactory" class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="annotatedClasses">
            <list>
                <value>cn.com.car.base.entity.Car</value>
            </list>
        </property>
        <property name="hibernateProperties">
            <value>classpath:hibernate.properties</value>
        </property>
    </bean>

    <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory"/>
    </bean>

</beans>

---

hibernate.properties配置文件

 hibernate.show_sql=true
hibernate.format_sql=false
hibernate.cache=org.hibernate.cache.EhCacheProvider
hibernate.dialect=org.hibernate.dialect.MySQL5Dialect
hibernate.connection.driverClassName=com.mysql.jdbc.Driver

hibernate.connection.url=jdbc:mysql://localhost:3306/car

hibernate.connection.username=car
hibernate.connection.password=123456

hibernate.c3p0.minPoolSize=5
hibernate.c3p0.maxPoolSize=50
hibernate.c3p0.timeout=1800
hibernate.c3p0.max_statement=200

---

DAO层

 package cn.com.car.base.dao.impl;

import java.util.HashMap;
import java.util.List;

import org.hibernate.Query;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import cn.com.car.base.dao.CarDao;
import cn.com.car.base.entity.Car;

public class CarDaoImpl extends HibernateDaoSupport implements CarDao {

    @Override
    public List<Car> getAllCar() {
        String sql="from T_CAR where 1=1";
        List<Car> list=this.getHibernateTemplate().find(sql);
        return list;
    }

    @Override
    public List<Car> getCarByParam(HashMap<String, String> param) {
        StringBuilder sql=new StringBuilder();
        sql.append("select * from T_CAR where 1=1");
        if(param!=null){
            if(param.get("type")!=null){
                String type=param.get("type");
                sql.append("and type="+type);
            }
            if(param.get("price")!=null){
                String price=param.get("price");
                sql.append("and price="+price);
            }

            Query query = this.getSession().createSQLQuery(sql.toString());
            List<Car> list=query.list();
            return list;
        }
        List<Car> list=this.getHibernateTemplate().find(sql.toString());
        return list;
    }

    @Override
    public Car getCarByModels(String models) {
        String hql = "from T_CAR t where 1=1 "
                  +" and t.models=? ";
            Query query = this.getSession().createQuery(hql).setString(0, models);
            return (Car) query.list().get(0);
    }

    @Override
    public Car getCarById(String id) {
        String hql = "from T_CAR t where 1=1 "
                  +" and t.id=? ";
            Query query = this.getSession().createQuery(hql).setString(0, id);
            return (Car) query.list().get(0);
    }

}

我是模仿别的项目搭建的，没有.hbm.xml，现在运行DAO层就出现
“org.hibernate.hql.ast.QuerySyntaxException: T_CAR is not mapped [from T_CAR where 1=1]”这样的错误。

解决方案

很明显，你的这两句HQL语句有问题

 @Override
    public Car getCarByModels(String models) {
        String hql = "from T_CAR t where 1=1 "
                  +" and t.models=? ";
            Query query = this.getSession().createQuery(hql).setString(0, models);
            return (Car) query.list().get(0);
    }

    @Override
    public Car getCarById(String id) {
        String hql = "from T_CAR t where 1=1 "
                  +" and t.id=? ";
            Query query = this.getSession().createQuery(hql).setString(0, id);
            return (Car) query.list().get(0);
    }

既然你创建的是createQuery 那么必须使用hql语法，因此

 String hql = "from T_CAR t where 1=1 "

这个语句中的 from后面应该跟的是对象，也就是表 T_CAR对应的实体 Car 。 HQL语句中所有的属性对应的不是表字段，而是表对应实体的属性，
因此 改成

 String hql = "from Car t where 1=1 "

就行了。下面这段代码不会报错

  @Override
    public List<Car> getCarByParam(HashMap<String, String> param) {
        StringBuilder sql=new StringBuilder();
        sql.append("select * from T_CAR where 1=1");
        if(param!=null){
            if(param.get("type")!=null){
                String type=param.get("type");
                sql.append("and type="+type);
            }
            if(param.get("price")!=null){
                String price=param.get("price");
                sql.append("and price="+price);
            }

            Query query = this.getSession().createSQLQuery(sql.toString());
            List<Car> list=query.list();
            return list;
        }
        List<Car> list=this.getHibernateTemplate().find(sql.toString());
        return list;
    }

是因为使用了createSQLQuery所以运行的是原生SQL，

解决方案二：

hibernate.hbm.xml配置
hibernate.hbm.xml配置
hibernate 的hbm.xml配置

解决方案三：

语句有问题，你的T_CAR 改成你自己的表名

解决方案四：

用SSH一般很少用到SQL，大多都是HQL