如何在spring中使用一个函数保存多行数据

Question

public ModelAndView postMethod(
        @ModelAttribute("attribute") ) throws Exception {
    ModelAndView mav = new ModelAndView("jsp");
    Date todayDate = new Date();
    Session session = null;
    Transaction transaction = null;
    if (issue_vendor.getOutward_item_code1() != null) {
        transaction = session.beginTransaction();
        session = sessionFactory.openSession();
        Query query = session.createQuery("FROM stock_register_dto where item_code=:code order by date desc");
        query.setInteger("code", issue_vendor.getOutward_item_code1());
        query.setMaxResults(1);
        List<stock_register_dto> list = query.list();
        System.out.println("result: " + list);
        for (stock_register_dto check : list) {
            Integer code1 = check.getItem_code();
            Integer stock1 = check.getStock();
            if (code1 == issue_vendor.getOutward_item_code1() && stock1 >= issue_vendor.getQuantity_issued1()) {
                this.master_service.saveRequirement(dto);
                session.flush();
                session.clear();
            }
        }
    }
    if (issue_vendor.getOutward_item_code2() != null) {

        transaction = session.beginTransaction();
        session = sessionFactory.openSession();
        Query query = session.createQuery("FROM stock_register_dto where item_code=:code order by date desc");
        query.setInteger("code", issue_vendor.getOutward_item_code2());
        query.setMaxResults(1);
        List<stock_register_dto> list = query.list();
        System.out.println("result: " + list);
        for (stock_register_dto check : html" target="_blank">list) {
            Integer code1 = check.getItem_code();
            Integer stock1 = check.getStock();
            if (code1 == issue_vendor.getOutward_item_code2() && stock1 >= issue_vendor.getQuantity_issued2()) {
                this.master_service.saveRequirement(dto);
                session.flush();
                session.clear();
            }
        }
    }
return mav;
}

类型异常报告

消息请求处理失败；嵌套异常是java.lang.NullPointerException

说明服务器遇到内部错误，导致它无法完成此请求。

例外情况

org.springframework.web.util.NestedServletException：请求处理失败；嵌套异常为java.lang.nullpointerexception org.springframework.web.servlet.frameworkservlet.processrequest（frameworkservlet.java:982)org.springframework.web.servlet.frameworkservlet.doPost（frameworkservlet.java:872)javax.servlet.service（httpservlet.java:650)org.springframework.web.servet.frameworkservet.service（

根本原因

java.lang.nullPointerException com.stock_issuance.controller.stock_issuance_controller.saveStock4(Sock_issuance_controller.java:118)Sun.Reflect.NativeMethodAccessorImpl.Invoke0（本机方法）al（RequestMappingHandlerAdapter.java:738)org.springFramework.web.servlet.mvc.method.abstractHandlerMethodAdapter.handle（AbstractHandlerMethodAdapter.java:85)org.springFramework.web.servlet.dispatch（DispatcherServlet.java:963)org.springFramework.web.servlet.dispatcherServlet.doService（DispatcherServlet.java:897)

注意，Apache Tomcat/7.0.68日志中提供了根本原因的完整堆栈跟踪。

Answer 1

您可以像下面这样使用hibernate批处理。

在hibernate配置文件中设置属性

hibernate.jdbc.batch_size 20

然后使用如下代码

Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();

for ( int i=0; i<100000; i++ ) {
    stock_register_dto dto = new stock_register_dto (....);
    session.save(dto);
    if ( i % 20 == 0 ) { //20, same as the JDBC batch size
        //flush a batch of inserts and release memory the memory
        session.flush();
        session.clear();
    }
}

transaction.commit();
session.close();