小编Val*_*kyi的帖子

我最近卸载了JDK 11并安装了JDK 8。为了确认，我想检查我的Windows 10机器上安装了哪个 JDK 。我输入java -versioncmd 然后收到错误消息

java 不被识别为内部或外部命令

问题：如何知道电脑上安装了哪个JDK版本？

有一个“完整实体”类：

@Entity(name = "vacancy_dec_to_words")
public class VacancyDescriptionToWords {

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long id;

    @JoinColumn(name = "vacancy_description_id")
    @ManyToOne(cascade = CascadeType.ALL)
    private VacancyDescription vacancyDescription;

    @JoinColumn(name = "words_id")
    @ManyToOne
    private Words words;

    @Column(name = "qty")
    private int qty;

    @Column(name = "create_date")
    private Date date;

    //...getters and setters

在某些方法中，我只需要使用此数据库中的 2 列：word_id和qty

我尝试以下方式：

预测 https://docs.spring.io/spring-data/jpa/docs/2.1.2.RELEASE/reference/html/#projections

public interface QtyWords {
    Long getWords();
    Integer getQty();
}

Jpa存储库：

*查询，我使用测试过并且它可行，我使用他JpaRepository：

@Repository
public interface SmallVDTWRepository extends JpaRepository<VacancyDescriptionToWords, Long> {

@Query(nativeQuery …

我是 Atom 和 javascript 的新手。

我确实下载了 Atom 并成功启动了他。但我不知道如何开始工作？

我看到并尝试在窗口中输入：

它的代码不相似，我没有看到“运行”或任何其他用于启动该代码的按钮。

如何在 Atom 或任何其他 IDE 中编码和启动 javascript 项目？

有MainController：

public class MainController {
    @FXML private RadioButton radioButton;
    @FXML private RadioButton radioButton2;

    @FXML public void addContact() {
        boolean b = radioButton.isSelected();
        boolean b2 = radioButton.isSelected();
    }
}

并且main.fxml：

<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="350.0" prefWidth="755.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ru.habrahabr.ui.MainController">
      <TableView fx:id="table" editable="true" prefHeight="200.0" prefWidth="405.0" tableMenuButtonVisible="true" AnchorPane.bottomAnchor="50.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
          <columnResizePolicy>
              <TableView fx:constant="CONSTRAINED_RESIZE_POLICY" />
          </columnResizePolicy>
      </TableView>

      <HBox alignment="CENTER" layoutX="21.0" layoutY="207.0" prefHeight="50.0" prefWidth="200.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="10.0" AnchorPane.rightAnchor="10.0">
            <RadioButton fx:id="radioButton" text="Male">
               <HBox.margin>
                  <Insets right="3.0"/>
               </HBox.margin>
            </RadioButton>

            <RadioButton fx:id="radioButton2" text="Female">
               <HBox.margin> …

我正在开发一个项目并使用弹簧.它工作正常,但当我添加一个数据库时,我有一些例外.

WARN com.zaxxer.hikari.util.DriverDataSource  : Registered driver with driverClassName=org.gjt.mm.mysql.Driver was not found, trying direct instantiation.
ERROR com.zaxxer.hikari.pool.HikariPool        : root - Exception during pool initialization.

java.sql.SQLException: Access denied for user ''@'localhost' (using password: YES)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965) ~[mysql-connector-java-5.1.46.jar:5.1.46]
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3976) ~[mysql-connector-java-5.1.46.jar:5.1.46]
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3912) ~[mysql-connector-java-5.1.46.jar:5.1.46]
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:871) ~[mysql-connector-java-5.1.46.jar:5.1.46]......

依赖关系:

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-thymeleaf</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
        <groupId>com.detectlanguage</groupId>
        <artifactId>detectlanguage</artifactId>
        <version>1.1.0</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-devtools</artifactId>
        <scope>runtime</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/org.jsoup/jsoup -->
    <dependency>
        <groupId>org.jsoup</groupId>
        <artifactId>jsoup</artifactId>
        <version>1.9.1</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <scope>runtime</scope>
    </dependency> …

我的任务是使用 Java 7 创建 spring-boot 应用程序。

所以，像往常一样，我在 start.spring.io 资源上创建了一个模板并通过 File -> New -> Project from Existing Sources...

当我使用 运行时jdk-8，一切正常，但是当我将 JDK 更改为 1.7 版（我也更改java-version为pom.xml）时，出现编译错误：

错误：java：无效标志：-parameters

截屏：

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 http://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>2.1.2.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.exercise</groupId>
<artifactId>quadratic</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>quadratic</name>
<description>Demo project for Spring Boot</description>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
</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-thymeleaf</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency> …

我有一个课程：

class AClass : CClass
class BClass : CClass

我需要在以下代码中使用它们：

POJO 类：

class SomeObject<T> where T : CClass
    T clazz;
    setClass(T clazz){
        this.clazz = clazz;
    .....

控制器类：

class ObjectExecutor{   

    private SomeObject<CClass> someObject;

    public ObjectExecutor execute(SomeObject<CClass> so){
        someObject = so; //exception when so - is the instance of AClass 
        return this;
    }

    public void build(){
        ....
    }
}

所以当我尝试实现它时：

SomeObject<AClass> soA = new....
soA.execute(soA) //exception point
    .build()

结果我得到了异常： can't cast AClass to CClass

所以我需要使用类似的东西：

class ObjectExecutor{   

    private SomeObject someObject; //without <> …

我尝试建立从詹金斯到 gitlab 的连接。

所以：

1. 我创建了 gitlab 令牌：

/*** 需要指出：我尝试了 gitlab 主机的所有可能选项：

https://gitlab.com https://gitlab.com/username https://gitlab.com/username/repository

但没有任何作用

2. 我添加了gitlab API插件、gitlab插件、git插件、gitlab身份验证插件。
3. 之后，我将 gitlab 令牌添加到 Jankins 凭证中：

4. 并在 gitlab 部分添加此令牌：

按“测试连接”后，我收到错误消息。我收到了来自詹金斯的日志，并且有以下错误堆栈跟踪：

2023-03-01 19:39:16.358+0000 [id=13]    WARNING o.e.j.s.h.ContextHandler$Context#log: Error while serving http://34.204.61.XXX:8080/manage/descriptorByName/com.dabsquared.gitlabjenkins.connection.GitLabConnection/testConnection
java.lang.IllegalArgumentException: RESTEASY003900: Unable to find a public constructor for provider class org.glassfish.jersey.jackson.internal.DefaultJacksonJaxbJsonProvider
        at org.jboss.resteasy.spi.ResteasyProviderFactory.createConstructorInjector(ResteasyProviderFactory.java:2844)
        at org.jboss.resteasy.spi.ResteasyProviderFactory.createProviderInstance(ResteasyProviderFactory.java:2833)
        at org.jboss.resteasy.spi.ResteasyProviderFactory.addMessageBodyReader(ResteasyProviderFactory.java:1068)
        at org.jboss.resteasy.spi.ResteasyProviderFactory.registerProvider(ResteasyProviderFactory.java:1841)
Caused: java.lang.RuntimeException: RESTEASY003940: Unable to instantiate MessageBodyReader
        at org.jboss.resteasy.spi.ResteasyProviderFactory.registerProvider(ResteasyProviderFactory.java:1846)
        at org.jboss.resteasy.spi.ResteasyProviderFactory.register(ResteasyProviderFactory.java:3065)
        at org.jboss.resteasy.spi.ResteasyProviderFactory.register(ResteasyProviderFactory.java:123)
        at org.jboss.resteasy.util.FeatureContextDelegate.register(FeatureContextDelegate.java:52)
        at org.jboss.resteasy.util.FeatureContextDelegate.register(FeatureContextDelegate.java:12)
        at org.glassfish.jersey.jackson.JacksonFeature.configure(JacksonFeature.java:107)
        at org.jboss.resteasy.spi.ResteasyProviderFactory.registerProviderInstance(ResteasyProviderFactory.java:2605)
        at org.jboss.resteasy.spi.ResteasyProviderFactory.registerProviderInstance(ResteasyProviderFactory.java:2233)
        at org.jboss.resteasy.spi.ResteasyProviderFactory.register(ResteasyProviderFactory.java:3036) …

我尝试使用句柄查询来更新SQL数据库中的表。

码：

    @Autowired
    private ProducerRepository producerRepository;

    public void update(Producer producer){

        String name = producer.getProducerName();
        long id = producer.getId();

//        producerRepository.save(producer); //this method works well.
        producerRepository.update(name, id); //handle attempt - throws exeption in this string
    }

生产者资料库：

@Repository
    public interface ProducerRepository extends JpaRepository<Producer, Long>{

        @Query(nativeQuery = true, value = "UPDATE producer SET producer_name = :pName WHERE id = :id")
        Producer update(
                @Param("pName") String pName,
                @Param("id") long id
        );
    }

producer实体的所有参数都是正确的，并且producerRepository.save(producer)运作良好。（也是我在控制台name和id字段中-好的）

因此，我可以将其保存producer …

我创建了数据库，它有一个 ENUM 表的引用，我在这个枚举的实体中有异常。

脚本示例：

CREATE TABLE status (
  code VARCHAR(40),
  status ENUM('not started', 'in progress', 'finished')
);

insert into status (code, status)
values (1, 'not started'),
       (2, 'in progress'),
       (3, 'finished');

CREATE TABLE `explorer` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `create_date` datetime DEFAULT NULL,
  `query` varchar(255) COLLATE utf8mb4_unicode_520_ci DEFAULT NULL,
  `title` varchar(255) COLLATE utf8mb4_unicode_520_ci DEFAULT NULL,
  `status_id` int DEFAULT NULL,
  PRIMARY KEY (`id`),
  FOREIGN KEY (status_id) REFERENCES status(code)
) ENGINE=MyISAM AUTO_INCREMENT=45 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;

因此，在创建表后，我确实为此表自动创建了实体：

• 探险家：

  @Entity
  @Table(name = "explorer", …

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