Java数据库更新语句的写法如下：

1. 使用JDBC：

String sql = "UPDATE table_name SET column1=value1, column2=value2 WHERE condition";
PreparedStatement statement = connection.prepareStatement(sql);
statement.executeUpdate();

2. 使用Hibernate：

Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
String hql = "UPDATE EntityName SET property1=value1, property2=value2 WHERE condition";
Query query = session.createQuery(hql);
query.executeUpdate();
transaction.commit();
session.close();