java.sql.SQLException: No value specified for parameter 1要怎么解决？

Z时代
2024-02-16
分类：IT

题目描述：我在用eclipse编写java代码时，出现java.sql.SQLException: No value specified for parameter 1这样的错误，要怎么解决？

题目来源及自己的思路

相关代码1.报错的代码：java.sql.SQLException: No value specified for parameter 1

at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:965)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
at com.mysql.jdbc.PreparedStatement.checkAllParametersSet(PreparedStatement.java:2256)
at com.mysql.jdbc.PreparedStatement.fillSendPacket(PreparedStatement.java:2236)
at com.mysql.jdbc.PreparedStatement.fillSendPacket(PreparedStatement.java:2166)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1986)
at com.cn.util.DBHelper.executeQuery(DBHelper.java:306)
at com.cn.dao.daoImpl.RoomDaoImpl.Money(RoomDaoImpl.java:56)
at com.cn.service.serviceImpl.RoomServiceImpl.Money(RoomServiceImpl.java:72)
at com.cn.view.OpenFrame$4.mouseClicked(OpenFrame.java:206)
at java.desktop/java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:278)
at java.desktop/java.awt.Component.processMouseEvent(Component.java:6620)
at java.desktop/javax.swing.JComponent.processMouseEvent(JComponent.java:3342)
at java.desktop/java.awt.Component.processEvent(Component.java:6382)
at java.desktop/java.awt.Container.processEvent(Container.java:2264)
at java.desktop/java.awt.Component.dispatchEventImpl(Component.java:4993)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2322)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4825)
at java.desktop/java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4934)
at java.desktop/java.awt.LightweightDispatcher.processMouseEvent(Container.java:4572)
at java.desktop/java.awt.LightweightDispatcher.dispatchEvent(Container.java:4504)
at java.desktop/java.awt.Container.dispatchEventImpl(Container.java:2308)
at java.desktop/java.awt.Window.dispatchEventImpl(Window.java:2773)
at java.desktop/java.awt.Component.dispatchEvent(Component.java:4825)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:772)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:721)
at java.desktop/java.awt.EventQueue$4.run(EventQueue.java:715)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:95)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:745)
at java.desktop/java.awt.EventQueue$5.run(EventQueue.java:743)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:391)
at java.base/java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:85)
at java.desktop/java.awt.EventQueue.dispatchEvent(EventQueue.java:742)
at java.desktop/java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:203)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:124)
at java.desktop/java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:113)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:109)
at java.desktop/java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.desktop/java.awt.EventDispatchThread.run(EventDispatchThread.java:90)

粘贴代码文本（请勿用截图）2.出现错误的地方：
public static <T> List<T> executeQuery(String sql,List<Object> params,Class<T> cls) throws Exception{

    Connection conn=null;
    PreparedStatement pstmt = null;
    ResultSet rs=null;
    List<T> data=new ArrayList<T>();
    try {
        conn=getConnection();
        pstmt=conn.prepareStatement(sql);//装载sql语句
        if(params!=null){
            //加入有？占位符，在执行之前把？占位符替换掉
            for(int i=0;i<params.size();i++){
                pstmt.setObject(i+1, params.get(i));
            }
        }
        rs=pstmt.executeQuery();
        //把查询出来的记录封装成对应的实体类对象
        ResultSetMetaData rsd=rs.getMetaData();//获得列对象,通过此对象可以得到表的结构，包括，列名，列的个数，列的数据类型
        while(rs.next()){
            T m=cls.newInstance();
            for(int i=0;i<rsd.getColumnCount();i++){
                String col_name=rsd.getColumnName(i+1);//获得列名
                Object value=rs.getObject(col_name);//获得列所对应的值
                Field field=cls.getDeclaredField(col_name);
                field.setAccessible(true);//给私有属性设置可访问权
                field.set(m, value);//给对象的私有属性赋值
                System.out.print("标准房间"+rsd.getColumnName(i+1));
            }
            data.add(m);
        }
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }finally{
        closeDB();
    }
    return data;
}