java.sql.SQLException：没有为参数5指定值，但字符串长度为4，而不是5

Question

i plan to use yahoo finance csv api to generate url to get stock realtime price and time. The url is like this http://download.finance.yahoo.com/d/quotes.csvs=%40%5YHOO,GOOG,MSFT,BAC&f=nsl1o&e=.csv , and it returns a table with 4 columns.

I use jdbc to store the data to Mysql, but there is always an error:"No value specified for parameter 5". The code is as below: public class Quote_Saver { private void connection(){ try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { e.printStackTrace(); } }

private String retrieveQuote() {
    StringBuffer buf = new StringBuffer();
    try {
        URL page = new URL("http://download.finance.yahoo.com/d/quotes.csv?s=%40%5YHOO,GOOG,MSFT,BAC&f=nsl1o&e=.csv");
        String line;
        URLConnection conn = page.openConnection();
        conn.connect();
        InputStreamReader in = new InputStreamReader(conn.getInputStream());
        BufferedReader data = new BufferedReader(in);
        while ((line = data.readLine()) != null) {
            buf.append(line + "\n");
        }
    } catch (MalformedURLException mue) {
        System.out.println("Bad URL: " + mue.getMessage());
    } catch (IOException ioe) {
        System.out.println("IO Error:" + ioe.getMessage());
    }
    return buf.toString();
}

//use the retrieveQuote class , pass it to data in ConnectionToMysql
private void ConnectionToMysql(String data){
    StringTokenizer tokens = new StringTokenizer(data, ",");
    String[] fields = new String[4];
    for (int i = 0; i < fields.length; i++) {
        fields[i] = stripQuotes(tokens.nextToken());
    }

    connection();
    String host ="jdbc:mysql://localhost/yahoo";
    String username = "root";
    String password = ".....";
    try {
        Connection connection = DriverManager.getConnection(host, username, password);
        String query = "insert into `stocks`(?,?,?,?) values (?,?,?,?);";
        PreparedStatement statement = (PreparedStatement) connection.prepareStatement(query);
        statement.setString(1, fields[0]);
        statement.setString(2, fields[1]);
        statement.setString(3, fields[2]);
        statement.setString(4, fields[3]);
        statement.executeUpdate();
        connection.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

private String stripQuotes(String input) {
    StringBuffer output = new StringBuffer();
    for (int i = 0; i < input.length(); i++) {
        if (input.charAt(i) != '\"') {
            output.append(input.charAt(i));
        }
    }
    return output.toString();
}

public static void main (String args[])
{
    Quote_Saver qd= new Quote_Saver();
    String data = qd.retrieveQuote();
    qd.ConnectionToMysql(data);
}

}

The error is

java.sql.SQLException: No value specified for parameter 5
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1086)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:989)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:975)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:920)
at com.mysql.jdbc.PreparedStatement.checkAllParametersSet(PreparedStatement.java:2594)
at com.mysql.jdbc.PreparedStatement.fillSendPacket(PreparedStatement.java:2569)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2415)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2366)
at com.mysql.jdbc.PreparedStatement.executeUpdate(PreparedStatement.java:2350)
at Quote_Saver.ConnectionToMysql(Quote_Saver.java:68)
at Quote_Saver.main(Quote_Saver.java:89)

But clearly, the string fields only has size of 4,so does my table columns, so my question is where is the parameter 5? and how to solve this? I'm new to java,plz help me. Thanks a lot!

Answer 1

Actually, you just made a minor mistake - probably a copy paste error.

The following line requires 8 parameters instead of 4 because you put question marks where you should have put column names.

insert into `stocks`(?,?,?,?) values (?,?,?,?);";

If you modify it as follows (replacing the column names with your real names from the stocks table) then it should function as you were expecting.

insert into stocks(ColumnNameOne, ColumnNameTwo, ColumnNameThree, ColumnNameFour)
values (?, ?, ?, ?);

Answer 2

Your sending 8 parameters by using, because each ? represent a parameter that required a value to be set at Run time.

String query = "insert into `stocks`(?,?,?,?) values (?,?,?,?);";

Your query should look like this:

String query = "insert into `stocks`(clmName1, clmName2, clmName3, clmName4) values (?,?,?,?);";