无法将数据保存到 mysql 数据库，在 gradle 项目中，bean 名称 'goal' 的 BindingResult 和普通目标对象都不能用作请求属性

Question

我正在观看教程，我创建了用户登录并验证了用户，当我创建 addGoal 时，我的目标不是进入我的 mysql 数据库，因为我能够登录所以我的数据库连接是正确，我正在使用 thymeleaf 和 javaconfig 作为我的注释，请帮助我，我是新手。我认为我的 addGoal.html 有错误，因为我正在使用 thymeleaf 我认为我没有正确执行，请有人帮我修复它，我认为我没有正确处理 @modelattribute

目标 class 是：

package com.pluralsight.model;

import hello.User;

import java.util.ArrayList;
import java.util.List;

import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.ElementCollection;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.persistence.OneToMany;
import javax.persistence.Table;

import org.hibernate.validator.constraints.Range;
import org.springframework.web.bind.annotation.ModelAttribute;


@Entity
@Table(name="goals")

public class Goal {

 public static final String FIND_ALL_GOALS = "findALLGoals";
 public static final String FIND_GOAL_REPORTS = "findGoalReports";
 
 @Id
 @GeneratedValue
 @Column(name="GOAL_ID")
 private Long id;
 
 @Range(min = 1, max = 120)
 @Column(name="MINUTES")
 private int minutes;
 
// @OneToMany(mappedBy="goal",cascade=CascadeType.ALL, fetch=FetchType.LAZY)
// private List<Exercise> exercises = new ArrayList<Exercise>();
 
 @ManyToOne
 @JoinColumn(name="USER_NAME")
 private User user;
// 
// public List<Exercise> getExercises() {
//  return exercises;
// }

 public User getUser() {
  return user;
 }

 public void setUser(User user) {
  this.user = user;
 }

 public Long getId() {
  return id;
 }


 public int getMinutes() {
  return minutes;
 }

// public void setExercises(List<Exercise> exercises) {
//  this.exercises = exercises;
// }

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

 public void setMinutes(int minutes) {
  this.minutes = minutes;
 }
 
}

这是我的goalcontroller.java

package com.pluralsight.controller;

import java.util.List;

import javax.servlet.http.HttpSession;
import javax.validation.Valid;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.validation.BindingResult;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.SessionAttributes;

import com.pluralsight.model.Goal;
import com.pluralsight.model.GoalReport;
import com.pluralsight.model.User;
import com.pluralsight.service.GoalService;

@Controller
@SessionAttributes("goal")
public class GoalController {

 @Autowired
 private GoalService goalService;
 
 @RequestMapping(value = "addGoal", method = RequestMethod.GET)
 public String addGoal(Model model, HttpSession session ) {
  //Goal goal = new Goal();
  
  Goal goal = (Goal)session.getAttribute("goal");
  
  if(goal == null){
   goal = new Goal();
   goal.setMinutes(10);
  }
  
  model.addAttribute("goal", goal);
  
  return "addGoal";
 }
 
 @RequestMapping(value = "addGoal", method = RequestMethod.POST)
 public String updateGoal(@Valid @ModelAttribute Goal goal, BindingResult result) {
  
  System.out.println("result has errors: " + result.hasErrors());
  
  System.out.println("Goal set: " + goal.getMinutes());
  
  if(result.hasErrors()) {
   return "addGoal";
  }else{
   goalService.save(goal);
  }
  
  return "redirect:index.jsp";
 }
 
 @RequestMapping(value="getGoals", method= RequestMethod.GET)
 public String getGoals(Model model){
  List<Goal> goals = goalService.findAllGoals();
  model.addAttribute("goals", goals);
  return "getGoals";
 }
 

 @RequestMapping(value="getGoalReports", method= RequestMethod.GET)
 public String getGoalReports(Model model){
  List<GoalReport> goalReports = goalService.findAllGoalReports();
  model.addAttribute("goalReports", goalReports);
  return "getGoalReports";
 }
}

这是我的 GoalRepository

package com.pluralsight.repository;

import org.springframework.data.jpa.repository.JpaRepository;

import org.springframework.stereotype.Repository;


import com.pluralsight.model.Goal;

@Repository("goalRepository")
public interface GoalRepository extends JpaRepository<Goal, Long>{
 
}

这是我的 GoalServiceImpl.java

package com.pluralsight.service;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import com.pluralsight.model.Goal;
import com.pluralsight.model.GoalReport;
import com.pluralsight.repository.GoalRepository;

@Service("goalService")
public class GoalServiceImpl implements GoalService {

 @Autowired
 private GoalRepository goalRepository;
 
 
 @Transactional
 public Goal save(Goal goal) {
  return goalRepository.save(goal);
 }


 public List<Goal> findAllGoals() {
  
  return (List<Goal>) goalRepository.findAll();
 }


 public List<GoalReport> findAllGoalReports() {
  return null;
//  return goalRepository.findAllGoalReports();
 }

}

这是我的 addGoal.html

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
 xmlns:th="http://www.thymeleaf.org"
 xmlns:sec="http://www.thymeleaf.org/thymeleaf-extras-springsecurity3">
<head>

</head>
<body>
 <div class="navbar navbar-fixed-top navbar-inverse">
  <div class="navbar-inner">
   <div class="container">
    <a class="brand" href="#"> Add Goal </a>
    <ul class="nav"></ul>
   </div>
  </div>
 </div>
 <div class="container">
  <div>
   <h1>Add Goal</h1>
   <p>Add your workout goal in minutes for the day.</p>
  </div>

  <form th:action="@{/addGoal}" method="post">
   <div>
    <label> Enter Minutes : <input type="text" name="minutes" />
    </label>
   </div>
   <div>
    <input type="submit" value="Submit" />
   </div>
  </form>

  <div class="control-group"></div>
 </div>
</body>
</html>

当我将 addGoal.html 中的表单更改为

  <form action="#" th:action="@{/addGoal}" th:object="${goal}" method="post">
   <p> enter Minutes: <input type="text" th:field="*{goal.minutes}"/></p>
   <p><input type="submit" value="enter goal minutes"/></p>
   
  </form>

然后我收到错误消息：bean 名称的 BindingResult 和普通目标对象都没有 'goal' 可用作请求属性

Answer 1

让我们退后一步，先关注不安的状态。对于您的表格，请使用此：

<form th:object="${goal}" th:action="@{/addGoal}" method="post">
            <div>
                <label> Enter Minutes : <input type="text" th:field="*{minutes}" />
                </label>
            </div>
            <div>
                <input type="submit" value="Submit" />
            </div>
        </form>

下一个变化：

@RequestMapping(value = "addGoal", method = RequestMethod.GET)
    public String addGoal(Model model, HttpSession session ) {
        Goal goal = new Goal();

        Goal sessionGoal = (Goal)session.getAttribute("goal");

        if(sessionGoal == null && sessionGoal.getMinutes() == 0){
            goal.setMinutes(10);
        }
else {
goal.setMinutes(sessionGoal.getMinutes());
}

        model.addAttribute("goal", goal);

        return "addGoal";
    }

你也在做return"redirect:index.jsp"；但是您正在使用 Thymeleaf。这是行不通的。您需要 "redirect:/index" 或 "redirect:/" 取决于您的家庭参数。

编辑 1：在 addGoal 的 POST 方法中更改以下行：

@RequestMapping(value = "addGoal", method = RequestMethod.POST)
    public String updateGoal(@Valid @ModelAttribute("goal") Goal goal, BindingResult result) {

无法将数据保存到 mysql 数据库，在 gradle 项目中，bean 名称 'goal' 的 BindingResult 和普通目标对象都不能用作请求属性

not able to savedata to mysql db, in gradle project, Neither BindingResult nor plain target object for bean name 'goal' available as request attribute

mysql

spring-security

thymeleaf

spring-boot