Question

我试图运行JDBC项目，sf员工管理和工资单我发布了我的代码，任何人都可以请求帮助

package com.ibs.emp;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;

public class DBConnectionTest {

    static ResultSet rs;
    static ResultSetMetaData rm;
    static int ch, nof;
    static double tax, total;
    static EmpDetails empDetails = new EmpDetails();

    public static double gross(){  
        if(EmpDetails.getHours() > 40)      
            return EmpDetails.getHours() * EmpDetails.getOrate();
        else
            return EmpDetails.getHours() * EmpDetails.getRate();
    }

    public static double net(){
        if(EmpDetails.getStatus().equalsIgnoreCase("married"))
            return total *= 0.75;
        else
            return total *= 0.70;
    }

    public static void display(double total, double tax){
        System.out.println("Gross pay: " + total);
        System.out.println("Net pay: " + tax);
    }

    public static void main(String[] args) throws NumberFormatException, IOException, SQLException, ClassNotFoundException {

        DBConnection dbConnection = new DBConnection();

        System.out.println("Connecting to a selected database...");
        Connection con = dbConnection.getConnection();
        System.out.println("Connected database successfully...");
        Statement st = con.createStatement();
        BufferedReader bin = new BufferedReader(new InputStreamReader(System.in));

        while(true){
            System.out.println("Choose Option");
            System.out.println("1. Select");
            System.out.println("2. Insert");
            System.out.println("3. Update");
            System.out.println("4. Delete");
            System.out.println("5. Payslip");
            System.out.println("0. Exit");
            ch = Integer.parseInt(bin.readLine());
            if (ch==1){
                rs = st.executeQuery("select * from emp");
                rm = rs.getMetaData();
                nof = rm.getColumnCount();
                for(int i=1; i<=nof; i++)
                {
                    System.out.print(rm.getColumnName(i)+"\t\t");
                }
                System.out.println();
                while(rs.next())
                {
                    for(int i=1; i<=nof; i++)
                    {
                        System.out.print(rs.getString(i) +"\t\t");
                    }
                    System.out.println();
                }
            }
            else if(ch==2)
            {
                System.out.println("Enter Name");
                empDetails.setEmp_name(bin.readLine());
                System.out.println("Enter Designation");
                empDetails.setEmp_designation(bin.readLine());
                System.out.println("Enter Emp_age");
                empDetails.setEmp_age( bin.read());
                System.out.println("Enter Salary");
                empDetails.setEmp_salary(bin.read());
                System.out.println("How many hours worked?");
                empDetails.setHours(bin.read());
                System.out.println("Rate of pay?");
                empDetails.setRate(bin.read());
                System.out.println("Over time rate?");
                empDetails.setOrate(bin.read());
                System.out.println("Married or Single?");
                empDetails.setStatus(bin.readLine());
                total = gross();
                tax = net();

                st.execute("insert into emp values('"+empDetails.getEmp_name()+"','"+empDetails.getEmp_age()+"','"+empDetails.getEmp_designation()+"','"+empDetails.getEmp_salary()+"','"+empDetails.getStatus()+"','"+empDetails.getOrate()+"','"+empDetails.getRate()+"','"+empDetails.getHours()+"','toatal','tax')");
                System.out.println("1 Record inserted");
            }
            else if(ch==3)
            {
                System.out.println("Enter Emp_id");
                empDetails.setEmp_id(bin.read());
                System.out.println("Enter Name");
                empDetails.setEmp_name( bin.readLine());
                System.out.println("Enter Designation");
                empDetails.setEmp_designation(bin.readLine());
                System.out.println("Enter Emp_age");
                empDetails.setEmp_age( bin.read());
                System.out.println("Enter Salary");
                empDetails.setEmp_salary(bin.read());
                System.out.println("How many hours worked?");
                empDetails.setHours(bin.read());
                System.out.println("Rate of pay?");
                empDetails.setEmp_name(bin.readLine());
                System.out.println("Over time rate?");
                empDetails.setEmp_name(bin.readLine());
                System.out.println("Married or Single?");
                empDetails.setEmp_name(bin.readLine());
                total = gross();
                tax = net();

                st.execute("update emp set emp_name='"+empDetails.getEmp_name()+"',emp_age='"+empDetails.getEmp_age()+"',emp_designation='"+empDetails.getEmp_designation()+"',emp_salary='"+empDetails.getEmp_salary()+"',status='"+empDetails.getStatus()+"',orate='"+empDetails.getOrate()+"',rate='"+empDetails.getRate()+"',hours='"+empDetails.getHours()+"',taotal='toatal',tax='tax' where emp_id ="+empDetails.getEmp_id());
                System.out.println("1 Record Updated");

            }
            else if(ch==4)
            {
                System.out.println("Enter Emp_id. to Delete :");
                empDetails.setEmp_id(bin.read());
                st.execute("delete from emp where eno ="+empDetails.getEmp_id());
                System.out.println("Record Deleted");
            }
            else if(ch==5)
            {
                System.out.println("Enter Emp_id");
                empDetails.setEmp_id(bin.read());
                rs = st.executeQuery("select * from emp");
                rm = rs.getMetaData();
                nof = rm.getColumnCount();
                for(int i=1; i<=nof; i++)
                {
                    System.out.print(rm.getColumnName(i)+"\t\t");
                }
                System.out.println();
                while(rs.next())
                {
                    for(int i=1; i<=nof; i++)
                    {
                        System.out.print(rs.getString(i) +"\t\t");
                    }
                    System.out.println();
                }
                display(total, tax);
            }
            else if(ch==0)
            {
                bin.close();
                con.close();
                System.exit(0);
            }
        }
    }
}

我收到了以下错误。 控制台

Exception in thread "main" java.lang.NumberFormatException: For input string: ""
    at java.lang.NumberFormatException.forInputString(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at com.ibs.emp.DBConnectionTest.main(DBConnectionTest.java)

欢迎任何建议，请帮助

Answer 1

运行代码时必须传递一些整数值，尝试在运行时传递一些参数。如果您正在使用eclipse IDE，那么您必须运行配置并单击参数选项卡以传递参数。

Answer 2

我认为如果没有选择选项会导致它。如果用户只是单击Enter而不选择选项，则可能会发生这种情况。

尝试替换该行：

ch = Integer.parseInt(bin.readLine());

通过

String readLine = bin.readLine();
ch = Integer.parseInt(readLine != null && !readLine.isEmpty() ? readLine : "0");

jdbc项目中的java.lang.NumberFormatException

2 个答案: