jpa使用uuid策略后无法手动设置id的问题及解决_Asp.net

jpa使用uuid策略后无法手动设置id

实体对象定义如下：

@data
@entity
@table(name = "sys_user")
public class userdo {

	/** 用户id */
	@id
	@genericgenerator(name = "uuid", strategy = "org.hibernate.id.uuidgenerator")
	@generatedvalue(generator = "uuid")
	@column(length = 36, nullable = false)
	private string userid;
	....
}

调用jpa的save方法，即使手动设置了id，手动设置的这个id也会被覆盖。

要求

当用户手动设置了id，以用户设置的id为准，否则使用uuid

解决方案

使用自定义id生成策略，判断id非空

import cn.hutool.core.util.strutil;
import lombok.extern.slf4j.slf4j;
import org.hibernate.engine.spi.sharedsessioncontractimplementor;
import org.hibernate.id.uuidgenerator;

import javax.persistence.id;
import java.io.serializable;
import java.lang.reflect.field;
import java.lang.reflect.invocationtargetexception;
import java.lang.reflect.method;

/**
 * 自定义uuid生成策略, 扩展 {@link org.hibernate.id.uuidgenerator}
 * 当用户设置了id，以用户设置的id为主，为空则生成uuid
 * {@link javax.persistence.id} 注解的字段只处理第一个
 *
 * @author qiudw
 * @date 7/7/2023
 */
@slf4j
public class customeruuidgenerator extends uuidgenerator {

	@override
	public serializable generate(sharedsessioncontractimplementor session, object obj) {
		class<?> clazz = obj.getclass();
		log.debug("generate id class: {}", clazz.getname());
		field[] fields = clazz.getdeclaredfields();
		try {
			for (field field : fields) {
				id idannotation = field.getannotation(id.class);
				if (idannotation == null) {
					continue;
				}
				string fieldname = field.getname();
				log.debug("field name: {}", fieldname);
				string getmethodname = generategetmethodname(fieldname);
				log.debug("get method name: {}", getmethodname);
				method declaredmethod = clazz.getdeclaredmethod(getmethodname);
				string idvalue = (string) declaredmethod.invoke(obj);
				if (strutil.isnotblank(idvalue)) {
					log.debug("use set value: {}", idvalue);
					return idvalue;
				}
			}
		} catch (nosuchmethodexception e) {
			log.error("no such method", e);
		} catch (invocationtargetexception | illegalaccessexception e) {
			log.error("invoke exception", e);
		}

		return super.generate(session, obj);
	}

	/**
	 * 生成get和set的方法名称
	 * type + 首字母大写(fieldname)
	 *
	 * @param fieldname userid
	 * @return type = set, fieldname = userid, 返回 setuserid
	 */
	private string generategetmethodname(string fieldname) {
		return "get" + fieldname.substring(0, 1).touppercase() + fieldname.substring(1);
	}

}

实体对象使用自定的策略

@data
@entity
@table(name = "sys_user")
public class userdo {

	/** 用户id */
	@id
	@genericgenerator(name = "uuid", strategy = "com.user.customeruuidgenerator")
	@generatedvalue(generator = "uuid")
	@column(length = 36, nullable = false)
	private string userid;
	....
}

现在可以手动设置id了