编译代码时，该代码使用jsoup从网站获取数据并保存到mysql数据库中。在添加约450个元素后，它崩溃并给出 Output ，链接的值被正确地写入和读取。一切都在代码中，我也正在使用mysql8。
以下是persistence.xml的休眠元素：
输出
WARN: HHH000342: Could not obtain connection to query metadata : null
Exception in thread "main" org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:275)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
at org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:107)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:116)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionCreator.makeConnection(DriverManagerConnectionCreator.java:37)
at org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.addConnections(DriverManagerConnectionProviderImpl.java:331)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.<init>(DriverManagerConnectionProviderImpl.java:250)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections.<init>(DriverManagerConnectionProviderImpl.java:228)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl$PooledConnections$Builder.build(DriverManagerConnectionProviderImpl.java:369)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:98)
at org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:73)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:107)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:246)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:145)
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:237)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
at org.hibernate.id.factory.internal.DefaultIdentifierGeneratorFactory.injectServices(DefaultIdentifierGeneratorFactory.java:152)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.injectDependencies(AbstractServiceRegistryImpl.java:286)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:243)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:214)
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.<init>(InFlightMetadataCollectorImpl.java:175)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:118)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.metadata(EntityManagerFactoryBuilderImpl.java:1202)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:1233)
at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:56)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:79)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:54)
at info.adam.jpa.domain.House.addHouse(House.java:19)
at info.adam.jpa.classes.HouseScraper.OlxHouseScraper(HouseScraper.java:80)
at info.adam.jpa.classes.MainMenu.Menu(MainMenu.java:18)
at info.adam.jpa.Main.main(Main.java:20)
Caused by: org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set
at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.determineDialect(DialectFactoryImpl.java:100)
at org.hibernate.engine.jdbc.dialect.internal.DialectFactoryImpl.buildDialect(DialectFactoryImpl.java:54)
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:137)
at org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
at org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:101)
at org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:263)
... 40 more
以下是最重要的类的代码：
主要
public static EntityManagerFactory entityManagerFactory;
public static EntityManager entityManager;
public static void main(String[] args) throws IOException {
entityManagerFactory = Persistence.createEntityManagerFactory("myDatabase");
entityManager = entityManagerFactory.createEntityManager();
MainMenu.Menu();
entityManager.close();
entityManagerFactory.close();
}
}
MainMenu
public class MainMenu {
public static void Menu() throws IOException {
System.out.println("Enter number to: "
+ "\n1.Refresh the property offers"
+ "\n2.Show the data"
+ "\n3.Show daily, weekly, monthly percentage change");
Scanner scan = new Scanner(System.in);
int chosenNumberInMenu = scan.nextInt();
switch (chosenNumberInMenu) {
case 1:
HouseScraper.OlxHouseScraper();
case 2:
case 3:
}
}
}
HouseScraper
public class HouseScraper {
public static void OlxHouseScraper() throws IOException {
Document doc = Jsoup
.connect("https://www.olx.pl/nieruchomosci/domy/malopolskie/?search[filter_float_price%3Afrom]=35000")
.get();
String numberOfPages = doc.select(".lheight24.tdnone.large.brc8.br3.block").text();
String[] numbersOfPages = numberOfPages.split(" ");
String lastPage = numbersOfPages[12];
int intLastPage = Integer.parseInt(lastPage);
for (int i = 1; i <= intLastPage; i++) {
StringBuilder urlOfPage = new StringBuilder();
urlOfPage.append(
"https://www.olx.pl/nieruchomosci/domy/malopolskie/?search[filter_float_price%3Afrom]=35000&page=");
urlOfPage.append(i);
String url = urlOfPage.toString();
System.out.println(url);
Document document = Jsoup.connect(url).get();
for (Element row : document.select("a.detailsLink.linkWithHash.link.marginright5")) {
String urlToOffer = row.attr("href");
Document linkToOffer = Jsoup.connect(urlToOffer).get();
if (urlToOffer.contains("otodom.pl")) {
// name
String name = linkToOffer.select(".css-1ld8fwi").text();
System.out.print(name + " ");
// price
String offerPrice = linkToOffer.select("div.css-1vr19r7").text();
String replaceString = offerPrice.replace("zł", "");
replaceString = replaceString.replace(" ", "");
replaceString = replaceString.replace("€", "");
replaceString = replaceString.replace(',', '.');
float price = Float.valueOf(replaceString);
System.out.print(price + " ");
// location
String location = linkToOffer.select("a.css-12hd9gg").text();
System.out.print(location);
System.out.println(" ");
House.addHouse(name, location, price, "otodom");
} else if (urlToOffer.contains("olx.pl")) {
// Name
String name = linkToOffer.select("h1").text();
System.out.print(name + " ");
// price
int finalPrice;
try {
String offerPrice = linkToOffer.select(".not-arranged.pricelabel__value").text();
String replaceString = offerPrice.replace("zł", "");
replaceString = replaceString.replace(" ", "");
replaceString = replaceString.replace("€", "");
replaceString = replaceString.replace(',', '.');
float price = Float.valueOf(replaceString);
finalPrice = (int) price;
System.out.print(finalPrice + " ");
} catch (Exception e) {
finalPrice = 0;
}
// Location
String location = linkToOffer.select("address").text();
System.out.print(location);
System.out.println(" ");
if (finalPrice != 0) {
House.addHouse(name, location, finalPrice, "olx");
}
}
}
}
}
**House**
@Entity
public class House extends Property {
public static EntityManagerFactory entityManagerFactory;
public static EntityManager entityManager;
public static void addHouse(String name, String location,float price, String link) {
entityManagerFactory = Persistence.createEntityManagerFactory("myDatabase");
entityManager = entityManagerFactory.createEntityManager();
House house = new House();
house.setName(name);
house.setLocation(location);
house.setPrice(price);
house.setLink(link);
entityManager.getTransaction().begin();
entityManager.persist(house);
entityManager.getTransaction().commit();
}
}
I know its not the best looking code, but im learning and open to criticism and advices!