在尝试创建 HibernateSession 应用程序时失败并出现异常:

Caused by: java.sql.SQLException: Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property. at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1055) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:956) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:926)

我找到了一种可能的解决方案 here但不幸的是，我无权访问数据库服务器，因此我无法更改其配置。 所以请注意这不是重复的，因为为数据库服务器更改提供了建议的解决方案，而在我的情况下，我没有这样的访问权限。

是否有机会在客户端解决此问题？您可以在下面找到我的 pom.xml 文件和我创建 session 的 java 代码。

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {
    private static final SessionFactory sessionFactory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        try {
            // Create the SessionFactory from hibernate.cfg.xml
            return new Configuration().configure().buildSessionFactory();
        } catch (Throwable ex) {
            // Make sure you log the exception, as it might be swallowed
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    public static void shutdown() {
        // Close caches and connection pools
        getSessionFactory().close();
    }
}

还有我的 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/maven-v4_0_0.xsd">
    ...
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>4.3.5.Final</version>
        </dependency>

        <dependency>
            <groupId>org.testng</groupId>
            <artifactId>testng</artifactId>
            <version>6.9.12</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project> 

最佳答案

一些进一步的调查表明问题正是在 MySQL v.8.0 中所做的更改:

Character Set Support

Important Change: The default character set has changed from latin1 to utf8mb4. These system variables are affected:

The default value of the character_set_server and character_set_database system variables has changed from latin1 to utf8mb4.

The default value of the collation_server and collation_database system variables has changed from latin1_swedish_ci to utf8mb4_0900_ai_ci.

所有这些更改都已在新版本的 mysql-connector-java 中处理，无需配置 MySQL。所以从 5.1.6 更改为 5.1.44 修复问题:

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.44</version>
</dependency>

关于java - 从服务器收到的未知初始字符集索引 '255'，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/50855622/