hibernate 使用数据库mysql 插入数据 乱码问题

出现以下问题:请大家帮忙解决
从网上查找了一下方法但是不行,
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate_basemapping?useUnicode=true&amp;characterEncoding=GBK</property>
我的具体操作如下:
写了一个测试方法:
public void testSaveUser1(){
Session session = null;
Transaction transaction = null;
User1 user = null;
try {
session = HibernateUtils.getSession();
transaction = session.beginTransaction();

user = new User1();
user.setName("旺旺");
user.setPassword("123");
user.setCreateTime(new Date());
user.setExpireTime(new Date());

session.save(user);

transaction.commit();
} catch (Exception e) {
// TODO: handle exception
transaction.rollback();
} finally {
HibernateUtils.closeSession(session);
}
}

出现如下的错误,不能插入重复,因为我设置了唯一性约束,但是名车出现了????乱码问题
Caused by: java.sql.BatchUpdateException: Duplicate entry '?—??—?' for key 2
at com.mysql.jdbc.PreparedStatement.executeBatchSerially(PreparedStatement.java:1213)
at com.mysql.jdbc.PreparedStatement.executeBatch(PreparedStatement.java:912)
at org.hibernate.jdbc.BatchingBatcher.doExecuteBatch(BatchingBatcher.java:48)
at org.hibernate.jdbc.AbstractBatcher.executeBatch(AbstractBatcher.java:242)<