java调用同一个包下的类怎么老报错呢

[zhljsdly]

在classes文件夹下的com\两个java文件和class：JDBConnection.java、Json.java。想在Json.java中调用JDBConnection类，查询数据库然后生成json。可在Json.java调用JDBConnection类时报错：找不到符号 类：JDBConnection。不是同一个包下不用import吗？怎么还是不行呢？
刚刚接触java，望大神们赐教。用的是cmd javac和java命令，没用工具。
JDBConnection.java

package com;
import java.sql.*;

public class JDBConnection {
private final String dbDriver = "com.microsoft.jdbc.sqlserver.SQLServerDriver"; //连接sql数据库的方法
private final String url = "jdbc:microsoft:sqlserver://10.28.160.8:1433;DatabaseName=dzgs";
private final String userName = "sa";
private final String password = "123";
private Connection con = null;

	public JDBConnection() {
		try {
		Class.forName(dbDriver).newInstance(); //加载数据库驱动
		} catch (Exception ex) {
		System.out.println("数据库加载失败");
		}
	}

	//创建数据库连接
	public boolean creatConnection() {
		try {
			con = DriverManager.getConnection(url, userName, password);
			con.setAutoCommit(true);
		
		} catch (SQLException e) {
			System.out.println(e.getMessage());
			System.out.println("creatConnectionError!");
		}
		return true;
	}

	//对数据库的增加、修改和删除的操作
	public boolean executeUpdate(String sql) {
	if (con == null) {
		creatConnection();
	}
	try {
		Statement stmt = con.createStatement();
		int iCount = stmt.executeUpdate(sql);
		System.out.println("操作成功，所影响的记录数为" + String.valueOf(iCount));
		} catch (SQLException e) {
		System.out.println(e.getMessage());
		System.out.println("executeUpdaterError!");
	}
		return true;
	}

//对数据库的查询操作
public ResultSet executeQuery(String sql) {
ResultSet rs;
try {
if (con == null) {
creatConnection();
}
Statement stmt = con.createStatement();
try {
rs = stmt.executeQuery(sql);
} catch (SQLException e) {
System.out.println(e.getMessage());
return null;
}
} catch (SQLException e) {
System.out.println(e.getMessage());
System.out.println("executeQueryError!");
return null;
}
return rs;
}

//关闭数据库的操作
public void closeConnection() {
if (con != null) {
try {
con.close();
} catch (SQLException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
System.out.println("Failed to close connection!");
} finally {
con = null;
}
}
}

}

Json.java

package com;  
import java.sql.*;

import java.util.HashMap;  
import java.util.Map;  
  
import org.json.JSONArray;  
import org.json.JSONException;  
import org.json.JSONObject;  


public class Json{  


  
    public static void main(String[] args) throws JSONException {  

	JDBConnection dbc = null;
	dbc = new JDBConnection();







        // 组Json串  
        String json = "{\"name\":\"reiz\"}";  
        // 根据Json串生成Json对象  
        JSONObject jsonObj = new JSONObject(json);  
        // 获得name键对应的值.  
        String name = jsonObj.getString("name");  
        System.out.println(name) ; // 输出 reiz  
          
        // 向Json中追加一个R字符串.initial:R  
        jsonObj.put("initial", name.substring(0, 1).toUpperCase());  
  
        // 向Json对象中加入对象类型数据(map)  
        Map<String, String> ingredients = new HashMap<String, String>();  
        ingredients.put("apples", "3kg");  
        ingredients.put("sugar", "1kg");  
        ingredients.put("pastry", "2.4kg");  
        ingredients.put("bestEaten", "outdoors");  
        jsonObj.put("ingredients", ingredients);  
          
        // 获得Map对象的字符串  
        String ingre = jsonObj.getString("ingredients");   
        System.out.println(ingre) ;  
        // 输出 {"apples":"3kg","sugar":"1kg","bestEaten":"outdoors","pastry":"2.4kg"}  
        // 把Map对象生成Json对象  
        JSONObject jsonIngre = new JSONObject(ingre);  
        System.out.println(jsonIngre.getString("apples")) ;  // 输出 3kg  
          
        System.out.println(jsonObj);  
        // 输出 {"ingredients":{"apples":"3kg","sugar":"1kg","bestEaten":"outdoors","pastry":"2.4kg"},"initial":"R","name":"reiz"}  
          
    }  
}  

[Defonds]

看看是不是包冲突了，导入了不同版本的 jar

[zhljsdly]

引用 1 楼 defonds 的回复:

看看是不是包冲突了，导入了不同版本的 jar

求解读，可能会哪里冲突呢