mysql JDBC连接

如果是GBK可以试试这个
jdbc:mysql://localhost/test?useUnicode=true&characterEncoding=GBK

utf-8编码
// 1. 注册驱动
    try {
     Class.forName("com.mysql.jdbc.Driver");
    } catch (ClassNotFoundException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }// Mysql 的驱动
   
    // 2. 获取数据库的连接
    java.sql.Connection conn=null;

    // 3. 获取表达式
    java.sql.Statement stmt=null;
  try {
   conn = java.sql.DriverManager.getConnection(
        "jdbc:mysql://localhost/test", "root", "root");
   stmt = conn.createStatement();
    stmt.executeUpdate("insert into topkcar(time, plateno) values('JDBC 中文测试', '密码')");
    java.sql.ResultSet rs = stmt.executeQuery("select * from topkcar");
    while(rs.next()) {
       System.out.println(rs.getString("time"));
       System.out.println(rs.getString("plateno"));
      }
     rs.close();
     stmt.close();
     conn.close();
  } catch (SQLException e) {
   e.printStackTrace();
  }