单个html页面中的Spring Boot maven mysql crud答案

【问题标题】：Spring boot maven mysql crud in single html page单个html页面中的Spring Boot maven mysql crud
【发布时间】：2022-01-14 04:31:01
【问题描述】：

我使用单个 HTML 表单创建了一个 spring boot crud 应用程序。单击编辑按钮时，我想在文本字段中显示数据以进行修改。但是在控制台中打印的特定数据没有出现在文本字段中。我找不到什么问题。

人物实体类

import java.util.Set;   
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name = "person")
public class Person {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "persion_id")
    private int persondId;

    @Column(name = "persion_name")
    private String personName;

    @Column(name = "persion_contact_no")
    private String personContactNo;

    @Column(name = "persion_address")
    private String personAddress;


    public Person() {

    }
    
    public Person(int persondId, String personName, String personContactNo, String personAddress) {
        this.persondId = persondId;
        this.personName = personName;
        this.personContactNo = personContactNo;
        this.personAddress = personAddress;
    }

    public int getPersondId() {
        return persondId;
    }

    public void setPersondId(int persondId) {
        this.persondId = persondId;
    }

    public String getPersonName() {
        return personName;
    }

    public void setPersonName(String personName) {
        this.personName = personName;
    }

    public String getPersonContactNo() {
        return personContactNo;
    }

    public void setPersonContactNo(String personContactNo) {
        this.personContactNo = personContactNo;
    }

    public String getPersonAddress() {
        return personAddress;
    }

    public void setPersonAddress(String personAddress) {
        this.personAddress = personAddress;
    }

    @Override
    public String toString() {
        return "Person [persondId=" + persondId + ", personName=" + personName + ", personContactNo=" + personContactNo
                + ", personAddress=" + personAddress + "]";
    }

}

控制器类

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

import com.obydul.spring.model.Person;
import com.obydul.spring.service.PersonService;

@Controller
public class PersonController {

    @Autowired
    private PersonService personService;

    @RequestMapping("/")
    public String home() {
        return "person";
    }

    @RequestMapping("/person")
    public String showPerson(Model model) {
        Person person = new Person();
        model.addAttribute("person", person);
        model.addAttribute("persons", personService.getAllPersons());
        return "person";
    }

    @RequestMapping(value = "/person_save", method = RequestMethod.POST)
    public String savePerson(@ModelAttribute Person person, Model model) {
        personService.savePerson(person);
        // model.addAttribute("persons", personService.getAllPersons());
        return "redirect:/person";
    }

    @RequestMapping("/person_edit/{persondId}")
    public String editPerson(@PathVariable int persondId, Model model) {
        model.addAttribute("person", personService.getPersonById(persondId));

        System.out.println("person edit :: " + personService.getPersonById(persondId));
        return "redirect:/person";
    }
    
    @GetMapping("/persons/{persondId}")
    public String deleteStudent(@PathVariable int persondId) {
        personService.deletePersonById(persondId);
        return "redirect:/person";
    }

}

Person.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head>
<meta charset="utf-8">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<title>Person Information Page</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet"
    href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css"
    integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm"
    crossorigin="anonymous">
</head>
<body>
<br>
    <div class="container">
        <div class="col-lg-10 col-md-8 col-sm-6 container justify-content-center card">
            <h3 class="text-center">Person Info</h3>
            <div class="card-body">
                <form action="#" th:action="@{/person_save}" th:object="${person}"
                    method="post">
                    
                    <div class="form-group">
                        <label>Person Name</label> <input type="text" name="personName"
                            th:field="*{personName}" class="form-control" />
                    </div>

                    <div class="form-group">
                        <label>Contact No</label> <input type="text"
                            name="personContactNo" th:field="*{personContactNo}"
                            class="form-control" />
                    </div>

                    <div class="form-group">
                        <label>Address</label> <input type="text" name="personAddress"
                            th:field="*{personAddress}" class="form-control" />
                    </div>


                    <div class="box-footer">

                        <button type="submit" class="btn btn-success">Save</button>
                        <button type="reset" class="btn btn-info">Reset</button>
                    </div>
                    <input type="hidden" id="persondId" th:field="*{persondId}"/>
                    
                    <br>
                    

            <table class="table table-striped table-bordered">
                <thead class="table-dark">
                    <tr>
                        <th class="text-center">Person Id</th>
                        <th class="text-center">Person Name</th>
                        <th class="text-center">Contact No</th>
                        <th class="text-center">Address</th>
                        <th class="text-center">Edit</th>
                        <th class="text-center">Delete</th>
                    </tr>
                </thead>
                <tbody>
                    <tr th:each="person: ${persons}">
                        <td class="text-center" th:text="${person.persondId}" />
                        <td th:text="${person.personName}" />
                        <td class="text-center" th:text="${person.personContactNo}" />
                        <td th:text="${person.personAddress}" />
                        <td  class="text-center">
                        <a th:href="@{/person_edit/{persondId}(persondId=${person.persondId})}" class="btn btn-primary">Edit</a>
                        </td>
                        <td  class="text-center">
                        <a th:href="@{/persons/{persondId}(persondId=${person.persondId})}" class="btn btn-danger">Delete</a>
                        </td>
                    </tr>

                </tbody>
            </table>
                </form>
            </div>

        </div>

    </div>
</body>
</html>

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.2</version>
        <relativePath /> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.obydul.spring </groupId>
    <artifactId>SpringBoot_Hibernate</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>SpringBoot_Hibernate</name>
    <description>spring boot hibernate one to many relationship</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

个人信息屏幕

控制台输出

人员编辑 :: 人员 [persondId=8, personName=John, personContactNo=021450000, personAddress=Dhaka]

【问题讨论】：

标签： spring spring-boot spring-mvc spring-data-jpa spring-data

【解决方案1】：

把它换成一行

@RequestMapping("/person_edit/{persondId}")

用这个：
@GetMapping("/person_edit/{persondId}")

【讨论】：

感谢您的宝贵回答。改变了，但和以前一样。
我可以看到你的api现在可以了。问题可能来自百里香叶部分。请从 Here 检查您的 thymleaf 语法

【解决方案2】：

根据https://www.thymeleaf.org/doc/tutorials/2.1/thymeleafspring.html#inputs，您不应该在input 元素形式的name 属性中指定。所以不是

<input type="text" name="personName" th:field="*{personName}" class="form-control" />

你应该使用

<input type="text" th:field="*{personName}" class="form-control" />

thymeleaf 将为您填充名称属性。我不确定这是否是未设置 value 的原因。

【讨论】：

【解决方案3】：

你写的是person*d*Id而不是personId

<a th:href="@{/person_edit/{persondId}(persondId=${person.persondId})}" class="btn btn-primary">Edit</a>

试试这个：

<a th:href="@{/person_edit/{personId}(personId=${person.personId})}" class="btn btn-primary">Edit</a>

它可能会起作用

【讨论】：

【解决方案4】：

这是工作。我像这样从控制器更改了编辑部分。

@GetMapping("/person_edit/{persondId}")
public String editPerson(@PathVariable int persondId, Model model) {
    model.addAttribute("person", personService.getPersonById(persondId));
    model.addAttribute("persons", personService.getAllPersons());
    return "person";
}

【讨论】：