部品番号レコードの管理に使用しているデータベースをホストするために、MySQL サーバー 5.6 を使用しています。Java クライアント フロント エンドがあります。クライアントとデータベース間の接続はすべて良好です。パーツを作成するためのパネルには、JComboBox-typeComboBox があります。これは、可能なすべてのパーツ タイプをデータベースに照会し、ドロップダウン メニューにタイプ番号を表示することによって取り込まれます。その JComboBox からの選択に応じて、tdescripTextField と seqTextField に適切な情報が入力されますが、選択した PartType 番号を使用してクエリされた適切な結果を JComboBox-matComboBox に取り込むことができません。
多くの System.out.println(); を使用しました。問題が発生しているコードの部分をデバッグし、String[] マットには正しい情報が含まれていることがわかりますが、matComboBox に割り当てられません。matComboBox = new JComboBox(); を初期化しないと通知されました。typeComboBox の直後に、matComboBox が null であるというコンパイル エラーが表示されます。
助けてくれてありがとう。
ps すべてのクエリ メソッドは、データベースから JSONArrays を返します。
class CreatePanel extends JPanel{
//JButtons
private JButton saveButton;
private JButton backButton;
//JComboBox
private JComboBox<?> typeComboBox;
private JComboBox<?> matComboBox;
//JTextField
private JTextField tdescripTextField;
private JTextField mdescripTextField;
private JTextField descripTextField;
private JTextField seqTextField;
private JTextField bpartTextField;
private JTextField cpartTextField;
private JTextField spartTextField;
//JLabel
private JLabel lblSeq;
private JLabel lblDescription;
private JLabel lblMatterialDescription;
private JLabel lblTypeDescription;
private JLabel lblType;
private JLabel lblMatterial;
private JLabel lblBosalPartNumber;
private JLabel lblCustomerPartNumber;
private JLabel lblSupplierPartNumber;
private JLabel lblCreateAPart;
private JLabel Bosal;
JPanel contentPane;
//StringPanel
public CreatePanel(final JPanel create)
{
//TextFields
tdescripTextField = new JTextField();
tdescripTextField.setEditable(false);
mdescripTextField = new JTextField();
mdescripTextField.setEditable(false);
descripTextField = new JTextField();
seqTextField = new JTextField();
seqTextField.setEditable(false);
bpartTextField = new JTextField();
bpartTextField.setEditable(false);
cpartTextField = new JTextField();
spartTextField = new JTextField();
//ComboBoxes
typeComboBox = new JComboBox<Object>();
matComboBox = new JComboBox<Object>();
JSONArray temp1 = new JSONArray();
String[] types = null;
try{
temp1 = con.queryReturnAllTypes();
types = new String[temp1.length()];
for(int i = 0; i < temp1.length(); i++){
types[i] = temp1.getJSONObject(i).get("PartType").toString();
}
}catch(Exception ex){/*ignore*/}
typeComboBox = new JComboBox<Object>(types);
typeComboBox.setEditable(true);
typeComboBox.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e){
int partType = Integer.valueOf((String) typeComboBox.getSelectedItem());
/*Debug*/System.out.println(partType);
JSONArray temp1 = new JSONArray();
JSONArray temp2 = new JSONArray();
String typeDescrip = null;
String seqNum = null;
String[] mats = null;
try{
temp1 = con.queryPartType(partType);
/*Debug*/System.out.println(temp1);
temp2 = con.queryMaterialPartType(partType);
/*Debug*/System.out.println(temp2);
mats = new String[temp2.length()];
/*Debug*/System.out.println(temp2.length());
typeDescrip = temp1.getJSONObject(0).get("TypeDescription").toString();
tdescripTextField.setText(typeDescrip);
seqNum = temp1.getJSONObject(0).get("SeqNumber").toString();
seqTextField.setText(seqNum);
for(int i = 0; i < temp2.length(); i++){
/*Debug*/System.out.println(i);
/*Debug*/System.out.println(temp2.getJSONObject(i).get("Material").toString());
mats[i] = temp2.getJSONObject(i).get("Material").toString();
/*Debug*/System.out.println(mats[i]);
}
for(int i = 0; i<mats.length; i++){
/*Debug*/System.out.println(mats[i]);
}
}catch(Exception ex){/*ignore*/}
for(int i = 0; i<mats.length; i++){
/*Debug*/System.out.println(mats[i]);
}
matComboBox = new JComboBox<Object>(mats);
matComboBox.setEditable(true);
}
});
//Labels
lblType = new JLabel("Type");
lblMatterial = new JLabel("Material");
lblTypeDescription = new JLabel("Type Description");
lblMatterialDescription = new JLabel("Material Description");
lblSeq = new JLabel("Seq");
lblDescription = new JLabel("Description");
lblBosalPartNumber = new JLabel("Bosal Part Number");
lblCustomerPartNumber = new JLabel("Customer Part Number");
lblSupplierPartNumber = new JLabel("Supplier Part Number");
lblCreateAPart = new JLabel("Create a Part Number");
ImageIcon bosal = new ImageIcon(getClass().getResource("/Images/bosal.jpg"));
Bosal = new JLabel(bosal);
setBackground(Color.DARK_GRAY);
//Buttons
ImageIcon save = new ImageIcon(getClass().getResource("/images/save1.jpg"));
saveButton = new JButton(save);
saveButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getSource() == saveButton){
int n = JOptionPane.showConfirmDialog(
frame,
"Are you sure you want to save part data?",
"Save:",
JOptionPane.YES_NO_OPTION,
JOptionPane.WARNING_MESSAGE);
}}});
add(saveButton);
ImageIcon back = new ImageIcon(getClass().getResource("/images/back1.jpg"));
backButton = new JButton(back);
backButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (e.getSource() == backButton)
{
setVisible(false);
frame.setLocation(550,220);
frame.setSize(700, 580);
main.setVisible(true);
}}});
add(backButton);
setupPanel();
};
private void setupPanel()
{
//Label Fonts
lblType.setFont(new Font("Tahoma", Font.BOLD, 14));
lblType.setForeground(Color.BLACK);
lblMatterial.setFont(new Font("Tahoma", Font.BOLD, 14));
lblMatterial.setForeground(Color.BLACK);
lblTypeDescription.setFont(new Font("Tahoma", Font.BOLD, 14));
lblTypeDescription.setForeground(Color.BLACK);
lblMatterialDescription.setFont(new Font("Tahoma", Font.BOLD, 14));
lblMatterialDescription.setForeground(Color.BLACK);
lblDescription.setFont(new Font("Tahoma", Font.BOLD, 14));
lblDescription.setForeground(Color.BLACK);
lblSeq.setFont(new Font("Tahoma", Font.BOLD, 14));
lblSeq.setForeground(Color.BLACK);
lblSupplierPartNumber.setFont(new Font("Tahoma", Font.BOLD, 14));
lblSupplierPartNumber.setForeground(Color.BLACK);
lblCreateAPart.setFont(new Font("EucrosiaUPC", Font.BOLD, 64));
lblCreateAPart.setForeground(Color.BLACK);
lblCustomerPartNumber.setFont(new Font("Tahoma", Font.BOLD, 14));
lblCustomerPartNumber.setForeground(Color.BLACK);
lblBosalPartNumber.setFont(new Font("Tahoma", Font.BOLD, 14));
lblBosalPartNumber.setForeground(Color.BLACK);
//Group Layout
GroupLayout groupLayout = new GroupLayout(this);
groupLayout.setHorizontalGroup(
groupLayout.createParallelGroup(Alignment.LEADING)
.addGroup(groupLayout.createSequentialGroup()
.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
.addGroup(groupLayout.createSequentialGroup()
.addGap(24)
.addComponent(Bosal, GroupLayout.PREFERRED_SIZE, 199, GroupLayout.PREFERRED_SIZE)
.addGap(6)
.addComponent(lblCreateAPart, GroupLayout.PREFERRED_SIZE, 434, GroupLayout.PREFERRED_SIZE))
.addGroup(groupLayout.createSequentialGroup()
.addGap(50)
.addComponent(lblType)
.addGap(121)
.addComponent(lblTypeDescription)
.addGap(163)
.addComponent(lblBosalPartNumber))
.addGroup(groupLayout.createSequentialGroup()
.addGap(50)
.addComponent(typeComboBox, GroupLayout.PREFERRED_SIZE, 79, GroupLayout.PREFERRED_SIZE)
.addGap(76)
.addComponent(tdescripTextField, GroupLayout.PREFERRED_SIZE, 211, GroupLayout.PREFERRED_SIZE)
.addGap(67)
.addComponent(bpartTextField, GroupLayout.PREFERRED_SIZE, 156, GroupLayout.PREFERRED_SIZE))
.addGroup(groupLayout.createSequentialGroup()
.addGap(50)
.addComponent(lblMatterial)
.addGap(101)
.addComponent(lblMatterialDescription)
.addGap(143)
.addComponent(lblCustomerPartNumber))
.addGroup(groupLayout.createSequentialGroup()
.addGap(50)
.addComponent(matComboBox, GroupLayout.PREFERRED_SIZE, 79, GroupLayout.PREFERRED_SIZE)
.addGap(76)
.addComponent(mdescripTextField, GroupLayout.PREFERRED_SIZE, 211, GroupLayout.PREFERRED_SIZE)
.addGap(67)
.addComponent(cpartTextField, GroupLayout.PREFERRED_SIZE, 156, GroupLayout.PREFERRED_SIZE))
.addGroup(groupLayout.createSequentialGroup()
.addGap(50)
.addComponent(lblSeq)
.addGap(129)
.addComponent(lblDescription)
.addGap(201)
.addComponent(lblSupplierPartNumber))
.addGroup(groupLayout.createSequentialGroup()
.addGap(331)
.addComponent(backButton, GroupLayout.PREFERRED_SIZE, 157, GroupLayout.PREFERRED_SIZE)
.addGap(41)
.addComponent(saveButton, GroupLayout.PREFERRED_SIZE, 156, GroupLayout.PREFERRED_SIZE))
.addGroup(groupLayout.createSequentialGroup()
.addGap(50)
.addComponent(seqTextField, GroupLayout.PREFERRED_SIZE, 58, GroupLayout.PREFERRED_SIZE)
.addGap(97)
.addComponent(descripTextField, GroupLayout.PREFERRED_SIZE, 211, GroupLayout.PREFERRED_SIZE)
.addGap(67)
.addComponent(spartTextField, GroupLayout.PREFERRED_SIZE, 156, GroupLayout.PREFERRED_SIZE)))
.addContainerGap(36, Short.MAX_VALUE))
);
groupLayout.setVerticalGroup(
groupLayout.createParallelGroup(Alignment.LEADING)
.addGroup(groupLayout.createSequentialGroup()
.addGap(32)
.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
.addComponent(Bosal, GroupLayout.PREFERRED_SIZE, 42, GroupLayout.PREFERRED_SIZE)
.addComponent(lblCreateAPart, GroupLayout.PREFERRED_SIZE, 52, GroupLayout.PREFERRED_SIZE))
.addGap(6)
.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
.addComponent(lblType)
.addComponent(lblTypeDescription)
.addComponent(lblBosalPartNumber))
.addGap(6)
.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
.addComponent(typeComboBox, GroupLayout.PREFERRED_SIZE, 23, GroupLayout.PREFERRED_SIZE)
.addGroup(groupLayout.createSequentialGroup()
.addGap(3)
.addComponent(tdescripTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
.addGroup(groupLayout.createSequentialGroup()
.addGap(3)
.addComponent(bpartTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)))
.addGap(6)
.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
.addComponent(lblMatterial)
.addComponent(lblMatterialDescription)
.addComponent(lblCustomerPartNumber))
.addGap(6)
.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
.addComponent(matComboBox, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addComponent(mdescripTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addComponent(cpartTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
.addGap(9)
.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
.addComponent(lblSeq)
.addComponent(lblDescription)
.addComponent(lblSupplierPartNumber))
.addGap(6)
.addGroup(groupLayout.createParallelGroup(Alignment.LEADING)
.addComponent(seqTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addComponent(descripTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addComponent(spartTextField, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
.addGap(37)
.addGroup(groupLayout.createParallelGroup(Alignment.TRAILING)
.addComponent(saveButton, 0, 0, Short.MAX_VALUE)
.addComponent(backButton, Alignment.LEADING, GroupLayout.PREFERRED_SIZE, 51, GroupLayout.PREFERRED_SIZE))
.addContainerGap(135, Short.MAX_VALUE))
);
setLayout(groupLayout);
}}