TypeMismatchException提供的ID类型错误 [英] TypeMismatchException the provided ID is of a wrong type

问题描述

在Hibernate中开发我的第一个应用程序时.尝试从数据库检索User对象时，出现以下异常:

While working on my first app in Hibernate. While trying to retrieve a User object from the DB i am getting the following exception:

org.hibernate.TypeMismatchException:提供了错误类型的ID，用于org.cw.form.User类.预期:类java.lang.Integer，得到了类java.lang.String在org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:109)在org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:906)在org.hibernate.impl.SessionImpl.load(SessionImpl.java:823)在org.hibernate.impl.SessionImpl.load(SessionImpl.java:816)

org.hibernate.TypeMismatchException: Provided id of the wrong type for class org.cw.form.User. Expected: class java.lang.Integer, got class java.lang.String at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:109) at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:906) at org.hibernate.impl.SessionImpl.load(SessionImpl.java:823) at org.hibernate.impl.SessionImpl.load(SessionImpl.java:816)

我使用以下postgreSQL创建了USERS表:

I have created the USERS table with the following postgreSQL:

CREATE SEQUENCE user2_id_seq; 

CREATE TABLE USERS(id integer NOT NULL DEFAULT nextval('user2_id_seq'), user_name   varchar(45) NOT NULL UNIQUE , password varchar(45) NOT NULL, email varchar(45) NOT NULL, PRIMARY KEY (id));

User实体是这样定义的:

And the User entity is defined as such:

@Entity @Table(name="USERS") public class User {

@Id
@Column(name="ID")
@GeneratedValue(strategy= GenerationType.IDENTITY)
private Integer id;

@Column(name="USER_NAME", unique = true)
private String userName;

@Column(name="PASSWORD")
private String password;

@Column(name="EMAIL")
private String email; .. all the getters and setters...

我想念什么吗?

推荐答案

如果显示如何检索用户，将更容易回答.根据消息:

It would be easier to answer if you would show how do you retrieve Users. Based to message:

Provided id of the wrong type for class org.cw.form.User. 
Expected: class java.lang.Integer, got class java.lang.String

我想您提供的是String而不是正确的类型(整数):

I guess you are providing String instead of correct type (Integer):

String userID = "1"; //Should be Integer userID = 1 instead
session.get(User.class, userID); 

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