我有一个简单的作业应用程序GUI，其中有一个类允许用户输入他们的个人信息，另一个类允许用户输入他们的工作历史，我想将所有信息存储在数据库中。我创建了mySQL数据库并成功连接但是当我在其中插入任何内容时，它显示数据库中的值为null。我不知道为什么。到目前为止，这是我的代码：
DataBase Class：
package database;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
public class ConnectDB
{
private String name, address, city, state, email, employer, position, start, end, duties, reason, DOB;
private int phoneNum, zipCode, employerPhonNum;
Connection conn = null;
/*
public static void main(String [] args) throws Exception
{
ConnectDB db = new ConnectDB();
db.getConnection();
}
*/
public boolean getConnection() throws Exception
{
boolean connected = false;
try
{
final String driver = "com.mysql.jdbc.Driver";
final String url = "jdbc:mysql://localhost:3306/JobApplication";
final String username = "root";
final String password = "Nasim8055";
Class.forName(driver);
conn = DriverManager.getConnection(url, username, password);
System.out.println("Connected");
connected = true;
}
catch(Exception e)
{
System.out.println(e);
connected = false;
}
return connected;
}
/*
* This method retrieves all the basic information and stores it
*/
public void getBasicInfo(String name, String address, String city, String state, int zip, int phoneNum,
String email, String DOB)
{
this.name = name;
this.address = address;
this.city = city;
this.state = state;
this.zipCode = zip;
this.phoneNum = phoneNum;
this.email = email;
this.DOB = DOB;
}
/*
* This method retrieves info from employment history
*/
public void getEmploymentInfo(String employer, String position, String start, String end, String duties, String reason, int phoneNum)
{
this.employer = employer;
this.position = position;
this.start = start;
this.end = end;
this.duties = duties;
this.reason = reason;
this.employerPhonNum = phoneNum;
}
public void insertDB()
{
Statement stmt = null;
int ID = 1;
try
{
if(getConnection()) // if there is a connection
{
stmt = conn.createStatement();
String sql = "INSERT INTO applicants " +
"VALUES ('"+ID+"', '"+name+"', '"+address+"', '"+city+"', '"+state+"', '"+zipCode+"', '"+phoneNum+"', '"+email+"', '"+employer+"', "
+ "'"+position+"', '"+start+"', '"+end+"', '"+employerPhonNum+"', '"+duties+"', '"+reason+"')";
stmt.executeUpdate(sql);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
public String getCity() {
return city;
}
public void setCity(String city) {
this.city = city;
}
public String getState() {
return state;
}
public void setState(String state) {
this.state = state;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getEmployer() {
return employer;
}
public void setEmployer(String employer) {
this.employer = employer;
}
public String getPosition() {
return position;
}
public void setPosition(String position) {
this.position = position;
}
public String getStart() {
return start;
}
public void setStart(String start) {
this.start = start;
}
public String getEnd() {
return end;
}
public void setEnd(String end) {
this.end = end;
}
public String getDuties() {
return duties;
}
public void setDuties(String duties) {
this.duties = duties;
}
public String getReason() {
return reason;
}
public void setReason(String reason) {
this.reason = reason;
}
public int getPhoneNum() {
return phoneNum;
}
public void setPhoneNum(int phoneNum) {
this.phoneNum = phoneNum;
}
public int getZipCode() {
return zipCode;
}
public void setZipCode(int zipCode) {
this.zipCode = zipCode;
}
public int getEmployerPhonNum() {
return employerPhonNum;
}
public void setEmployerPhonNum(int employerPhonNum) {
this.employerPhonNum = employerPhonNum;
}
public String getDOB() {
return DOB;
}
public void setDOB(String DOB) {
this.DOB = DOB;
}
}
BasicInfo类排除了一些不相关的方法：
public class BasicInfoWindow extends JPanel
{
private JTextField txtName, txtAddress, txtCity, txtState, txtZipCode, txtPhoneNumber, txtEmail;
private JComboBox cbDate, cbYear, cbMonth;
private JLabel labelName, labelAddress, labelCity, labelState, labelZipCode, labelPhoneNumber, labelEmail, labelDOB;
private JButton btnClear;
public BasicInfoWindow()
{
createView();
}
private void createView()
{
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
add(panel);
northPanel(panel);
centerPanel(panel);
southPanel(panel);
}
public void writeToDB()
{
ConnectDB db = new ConnectDB();
String DOB = cbMonth.getSelectedItem() + " " + cbDate.getSelectedItem() + " " + cbYear.getSelectedItem();
db.getBasicInfo(txtName.getText(), txtAddress.getText(), txtCity.getText(), txtState.getText(),
Integer.parseInt(txtZipCode.getText()), Integer.parseInt(txtPhoneNumber.getText()), txtEmail.getText(), DOB);
}
就业历史课程排除不相关的方法
public class EmploymentHistoryWindow extends JPanel
{
private JButton btnClear, btnNext, btnPrevious, btnAddMoreEmployment;
private JLabel labelEmployer, labelPosition, labelStart, labelEnd, labelDuties,labelReason, labelPhoneNum;
private JTextField txtEmployer, txtPosition, txtStart, txtEnd, txtPhoneNum;
private JTextArea areaDuties, areaReason;
private JTabbedPane tabbedPane = new JTabbedPane();
public EmploymentHistoryWindow()
{
createView();
}
private void createView()
{
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
tabbedPane.add("Employment", panel);
add(tabbedPane);
northPanel(panel);
centerPanel(panel);
southPanel(panel);
}
public void writeToDB()
{
ConnectDB db = new ConnectDB();
db.getEmploymentInfo(txtEmployer.getText(), txtPosition.getText(), txtStart.getText(), txtEnd.getText(),
areaDuties.getText(), areaReason.getText(), Integer.parseInt(txtPhoneNum.getText()));
}