java.sql.SQLException:参数索引超出范围（1>；参数数，即0）java客户端

给出那个错误，但我不明白为什么，我用了？作为值，有3个参数。 我必须向数据库中添加一个新用户，不要关注文本字段中的密码，然后我将其转换为密码字段

private void caricaActionPerformed(java.awt.event.ActionEvent evt) {                                       
    String username = null,ruolo=null,password;
    username = usernameField.getText();
    password = passwordField.getText();
    ruolo = ruoloField.getText();
    try {
        aggiungiUtente(username,password,ruolo);
    } catch (SQLException ex) {
        Logger.getLogger(InserisciUtente.class.getName()).log(Level.SEVERE, null, ex);
    } 
}                                      
private void aggiungiUtente(String username,String password,String ruolo) throws SQLException {
    Connection conn;
    String url="jdbc:mysql://localhost:3306/gestionale",user="root",psw="141299Fm";
    conn = (Connection) DriverManager.getConnection(url,user,psw);
    conn.setAutoCommit(false);
    String sql= "insert into Utenti('username',password','ruolo') VALUES(?,?,?)";
    try{
    PreparedStatement st = conn.prepareStatement(sql);
    st.setString(1, username);
    st.setString(2, password);
    st.setString(3, ruolo);

    ResultSet rs = st.executeQuery();

    System.out.println(rs);
    }catch(SQLException e)
    {
        Logger.getLogger(InserisciUtente.class.getName()).log(Level.SEVERE, null, e);
    }


}

---

---

Insert语句属性中的引号未正确关闭。

密码

没有起始引号

将Insert语句更改为

String sql=“插入到Utenti（'username'，password'，'ruolo'）值（？，？）”

到

在Insert语句中指定属性时，无需给出
“
。
Insert语句中缺少一个”。也许你不需要“反正”这个词，倒逗号“？你是说，也就是单引号，即
“
”？它不仅仅是“不需要给出
”
”。您不能给出
”
，因为它们用于字符文本，例如
“Hello”
，而
INSERT
语句需要列名，而不是字符文本。@Andreas这就是我要说的，属性不是用引号指定的“无需”表示它是可选的，例如“您不需要，但您可以”。这里不是这样，所以说“不需要”是不准确的措辞。@Andreas你太自信了，没有引用任何消息来源就坚持。如果列名中有空格，您认为会发生什么情况？看见说你不能给'，因为这些是用于字符文字是完全错误的。
    run:
apr 09, 2017 10:38:51 PM InserisciUtente aggiungiUtente
GRAVE: null
java.sql.SQLException: Parameter index out of range (1 > number of parameters, which is 0).
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1074)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:988)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:974)
    at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
    at com.mysql.jdbc.PreparedStatement.checkBounds(PreparedStatement.java:3813)
    at com.mysql.jdbc.PreparedStatement.setInternal(PreparedStatement.java:3795)
    at com.mysql.jdbc.PreparedStatement.setString(PreparedStatement.java:4616)
    at InserisciUtente.aggiungiUtente(InserisciUtente.java:136)
    at InserisciUtente.caricaActionPerformed(InserisciUtente.java:123)
    at InserisciUtente.access$000(InserisciUtente.java:20)
    at InserisciUtente$1.actionPerformed(InserisciUtente.java:63)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6533)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
    at java.awt.Component.processEvent(Component.java:6298)
    at java.awt.Container.processEvent(Container.java:2236)
    at java.awt.Component.dispatchEventImpl(Component.java:4889)
    at java.awt.Container.dispatchEventImpl(Container.java:2294)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
    at java.awt.Container.dispatchEventImpl(Container.java:2280)
    at java.awt.Window.dispatchEventImpl(Window.java:2746)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
    at java.awt.EventQueue$4.run(EventQueue.java:731)
    at java.awt.EventQueue$4.run(EventQueue.java:729)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109)
    at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227)
    at java.awt.Dialog.show(Dialog.java:1084)
    at java.awt.Component.show(Component.java:1671)
    at java.awt.Component.setVisible(Component.java:1623)
    at java.awt.Window.setVisible(Window.java:1014)
    at java.awt.Dialog.setVisible(Dialog.java:1005)
    at FormUtenti.jButton1ActionPerformed(FormUtenti.java:104)
    at FormUtenti.access$000(FormUtenti.java:11)
    at FormUtenti$2.actionPerformed(FormUtenti.java:64)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6533)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
    at java.awt.Component.processEvent(Component.java:6298)
    at java.awt.Container.processEvent(Container.java:2236)
    at java.awt.Component.dispatchEventImpl(Component.java:4889)
    at java.awt.Container.dispatchEventImpl(Container.java:2294)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
    at java.awt.Container.dispatchEventImpl(Container.java:2280)
    at java.awt.Window.dispatchEventImpl(Window.java:2746)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
    at java.awt.EventQueue$4.run(EventQueue.java:731)
    at java.awt.EventQueue$4.run(EventQueue.java:729)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109)
    at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:184)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:229)
    at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:227)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:227)
    at java.awt.Dialog.show(Dialog.java:1084)
    at java.awt.Component.show(Component.java:1671)
    at java.awt.Component.setVisible(Component.java:1623)
    at java.awt.Window.setVisible(Window.java:1014)
    at java.awt.Dialog.setVisible(Dialog.java:1005)
    at FrameMenu.pulsanteUtentiActionPerformed(FrameMenu.java:155)
    at FrameMenu.access$200(FrameMenu.java:11)
    at FrameMenu$3.actionPerformed(FrameMenu.java:65)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.Component.processMouseEvent(Component.java:6533)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
    at java.awt.Component.processEvent(Component.java:6298)
    at java.awt.Container.processEvent(Container.java:2236)
    at java.awt.Component.dispatchEventImpl(Component.java:4889)
    at java.awt.Container.dispatchEventImpl(Container.java:2294)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4888)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4525)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4466)
    at java.awt.Container.dispatchEventImpl(Container.java:2280)
    at java.awt.Window.dispatchEventImpl(Window.java:2746)
    at java.awt.Component.dispatchEvent(Component.java:4711)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
    at java.awt.EventQueue$4.run(EventQueue.java:731)
    at java.awt.EventQueue$4.run(EventQueue.java:729)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

**Stack Trace **

String sql= "insert into Utenti(username,password,ruolo) VALUES(?,?,?)";