使用idea根据数据库表生成java model类，基于hibernate

很多场景下我们需要根据已有的数据库表，生成对应的java bean，而且还希望生成的java类格式正确、命名规范。

使用idea可以轻松的完成这个功能。

举例，我新建一个springboot项目，勾选mysql、jpa即可，在idea找到Database界面，新建Data source——MySQL，填写数据连接信息后即可。

此时就可以生成简单的pojo类了，注意，此时还没有使用hibernate呢，就是idea的这个Database功能就可以生成pojo类了，只不过无格式。在界面上数据库名右键，出来下面的界面。

点Generate POJOs.clj即可

可以看到生成类很粗糙，就是把列名复制，完全照搬，我们希望的更格式化的pojo类，所以我们要使用hibernate来反向生成。

在resource文件夹下创建hibernate.cfg.xml文件

<?xml version="1.0" encoding="UTF-8"?>
<hibernate-configuration>
    <session-factory>
        <!-- Database connection settings -->
        <property name = "connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name = "connection.url">jdbc:mysql://localhost/test</property>
        <property name = "connection.username">root</property>
        <property name = "connection.password">root</property>
        <!-- JDBC connection pool (use the built-in) -->
        <!--
        <property name="connection.pool_size">1</property>
         -->
        <!-- SQL dialect -->
        <property name = "dialect">org.hibernate.dialect.MySQLDialect</property>
        <!-- Enable Hibernate's automatic session context management -->
        <property name = "current_session_context_class">thread</property>
 
        <!-- Echo all executed SQL to stdout -->
        <property name = "show_sql">true</property>
        <!-- Drop and re-create the database schema on startup -->
        <!--
        <property name="hbm2ddl.auto">update</property>
        -->
 
    </session-factory>
</hibernate-configuration>

配置基本信息，此时idea会有提醒

我们点击箭头处，或者在project structure里如下图，添加hibernate configuration

只有配置了hibernate，才能使用hibernate的反向生成功能。

然后点击View-Tool Windows-Persistence，注意，如果没有配置hibernate的话，是没有Persistence这个选项的。

然后如下图操作，右键点击后会弹出下图界面。

然后就可以设置要生成的类所在的包名，前缀、后缀，还可以修改pojo类的类型，譬如success字段可以修改为boolean，最下面勾选JPA注解。点击OK就行了。

package com.tianyalei.hibernate;
 
import javax.persistence.*;
import java.sql.Timestamp;
 
/**
 * Created by wuweifeng on 2017/10/11.
 */
@Entity
@Table(name = "user", schema = "test", catalog = "")
public class UserEntity {
    private long id;
    private int credits;
    private String lastIp;
    private Timestamp lastVisit;
    private String password;
    private int userId;
    private String userName;
    private String name;
    private boolean success;
 
    @Id
    @Column(name = "id")
    public long getId() {
        return id;
    }
 
    public void setId(long id) {
        this.id = id;
    }
 
    @Basic
    @Column(name = "credits")
    public int getCredits() {
        return credits;
    }
 
    public void setCredits(int credits) {
        this.credits = credits;
    }
 
    @Basic
    @Column(name = "last_ip")
    public String getLastIp() {
        return lastIp;
    }
 
    public void setLastIp(String lastIp) {
        this.lastIp = lastIp;
    }
 
    @Basic
    @Column(name = "last_visit")
    public Timestamp getLastVisit() {
        return lastVisit;
    }
 
    public void setLastVisit(Timestamp lastVisit) {
        this.lastVisit = lastVisit;
    }
 
    @Basic
    @Column(name = "password")
    public String getPassword() {
        return password;
    }
 
    public void setPassword(String password) {
        this.password = password;
    }
 
    @Basic
    @Column(name = "user_id")
    public int getUserId() {
        return userId;
    }
 
    public void setUserId(int userId) {
        this.userId = userId;
    }
 
    @Basic
    @Column(name = "user_name")
    public String getUserName() {
        return userName;
    }
 
    public void setUserName(String userName) {
        this.userName = userName;
    }
 
    @Basic
    @Column(name = "name")
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    @Basic
    @Column(name = "success")
    public boolean isSuccess() {
        return success;
    }
 
    public void setSuccess(boolean success) {
        this.success = success;
    }
 
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
 
        UserEntity that = (UserEntity) o;
 
        if (id != that.id) return false;
        if (credits != that.credits) return false;
        if (userId != that.userId) return false;
        if (success != that.success) return false;
        if (lastIp != null ? !lastIp.equals(that.lastIp) : that.lastIp != null) return false;
        if (lastVisit != null ? !lastVisit.equals(that.lastVisit) : that.lastVisit != null) return false;
        if (password != null ? !password.equals(that.password) : that.password != null) return false;
        if (userName != null ? !userName.equals(that.userName) : that.userName != null) return false;
        if (name != null ? !name.equals(that.name) : that.name != null) return false;
 
        return true;
    }
 
    @Override
    public int hashCode() {
        int result = (int) (id ^ (id >>> 32));
        result = 31 * result + credits;
        result = 31 * result + (lastIp != null ? lastIp.hashCode() : 0);
        result = 31 * result + (lastVisit != null ? lastVisit.hashCode() : 0);
        result = 31 * result + (password != null ? password.hashCode() : 0);
        result = 31 * result + userId;
        result = 31 * result + (userName != null ? userName.hashCode() : 0);
        result = 31 * result + (name != null ? name.hashCode() : 0);
        result = 31 * result + (success ? 1 : 0);
        return result;
    }
}