您好，我刚开始研究本春季教程：https://spring.io/guides/gs/accessing-data-mysql/
我正在使用提供的代码并按照建议设置MySql数据库，但是使用cURL命令会出现以下错误：
curl localhost：8080 / demo / add -d name = First -d email=someemail@someemailprovider.com <！doctype html> HTTP状态500内部服务器Errorbody {font-family：Tahoma，Arial，sans-serif; } h1，h2，h3，b {color：white; background-color：＃525D76;} h1 {font-size：22px;} h2 {font-size：16px;} h3 {font-size：14px;} p { font-size：12px;} a {color：black;} .line {height：1px; background-color：＃525D76; border：none;}
HTTP状态500内部服务器错误
MainController：
package Controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;
import Repository.UserRepository;
import com.example.demo.Model.*;
@Controller // This means that this class is a Controller
@RequestMapping(path="/demo") // This means URL's start with /demo (after Application path)
public class MainController {
@Autowired // This means to get the bean called userRepository
// Which is auto-generated by Spring, we will use it to handle the data
private UserRepository userRepository;
@PostMapping(path="/add") // Map ONLY POST Requests
public @ResponseBody String addNewUser (@RequestParam String name
, @RequestParam String email) {
// @ResponseBody means the returned String is the response, not a view name
// @RequestParam means it is a parameter from the GET or POST request
User n = new User();
n.setName(name);
n.setEmail(email);
userRepository.save(n);
return "Saved";
}
@GetMapping(path="/all")
public @ResponseBody Iterable<User> getAllUsers() {
// This returns a JSON or XML with the users
return userRepository.findAll();
}
}
User.java
package com.example.demo.Model;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
@Entity // This tells Hibernate to make a table out of this class
public class User {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private Integer id;
private String name;
private String email;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}
UserRepository.java
package Repository;
import org.springframework.data.repository.CrudRepository;
import com.example.demo.Model.User;
// This will be AUTO IMPLEMENTED by Spring into a Bean called userRepository
// CRUD refers Create, Read, Update, Delete
public interface UserRepository extends CrudRepository<User, Integer> {
}
application.properties
spring.jpa.hibernate.ddl-auto=update
spring.datasource.url=jdbc:mysql://${MYSQL_HOST:localhost}:3306/db_example
spring.datasource.username=springuser
spring.datasource.password=ThePassword
Gradle.build
plugins {
id 'org.springframework.boot' version '2.3.2.RELEASE'
id 'io.spring.dependency-management' version '1.0.9.RELEASE'
id 'java'
id 'war'
}
group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '11'
repositories {
mavenCentral()
}
dependencies {
implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
implementation 'org.springframework.boot:spring-boot-starter-web'
runtimeOnly 'mysql:mysql-connector-java'
providedRuntime 'org.springframework.boot:spring-boot-starter-tomcat'
testImplementation('org.springframework.boot:spring-boot-starter-test') {
exclude group: 'org.junit.vintage', module: 'junit-vintage-engine'
}
}
test {
useJUnitPlatform()
}
控制台日志
似乎没有使用数据库2020-08-06 16:38:44.272 INFO 17940 --- [ main] .s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 9ms. Found 0 JPA repository interfaces.
2020-08-06 16:38:46.196 WARN 17940 --- [ task-1] o.h.e.j.e.i.JdbcEnvironmentInitiator : HHH000342: Could not obtain connection to query metadata : The server time zone value 'GMT Summer Time' is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the 'serverTimezone' configuration property) to use a more specifc time zone value if you want to utilize time zone support.
2020-08-06 16:39:18.344 INFO 17940 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet'
2020-08-06 16:39:18.344 INFO 17940 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet'
2020-08-06 16:39:18.348 INFO 17940 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 4 ms
2020-08-06 16:39:18.363 ERROR 17940 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.DataAccessResourceFailureException: Could not create JPA EntityManager; nested exception is org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]] with root cause
org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set
```
```
2020-08-06 16:39:18.369 ERROR 17940 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] threw exception
org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set
```
```
2020-08-06 16:39:18.370 ERROR 17940 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost] : Exception Processing ErrorPage[errorCode=0, location=/error]
org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.dao.DataAccessResourceFailureException: Could not create JPA EntityManager; nested exception is org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
```
答案 0 :(得分：0)
您的代码中有两个问题
1-您尚未将@Repository批注添加到存储库类。因此，系统无法找到任何存储库接口
2-您正在执行错误的curl命令。您正在发送名称和电子邮件作为正文参数。理想情况下，您应该将它们作为查询参数发送。这就是在控制器中使用@RequestParam时的预期结果
curl --location --request POST 'localhost:8080/demo/add?name=First&email=email@dds.com'
答案 1 :(得分：0)
由于控制台中的错误，我认为您在application.properties中缺少此信息：
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8Dialect
选择与您的mysql版本匹配的方言。
答案 2 :(得分：0)
需要将以下内容附加到数据源上
?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC