[Java]小作品－付款系統

原因：

現有一家3C商店，要求你設計一個簡易收銀找零應用程式需求為：

1.商品資料：

2.總價超過4000元，打96折

3.會員再打95折

• 使用MVC來做出一個簡單作品
• M(Model)

1. DataBase(表)

2. Class－＞uml圖

這次的uml圖比較複雜一點，lcd存的是價格，後面的lcdS存的是數量(其他也是這樣的模式)

• V(View)

－＞UI介面

－＞新增畫面

• Controller
• [database]
• 注意，database中不能含主程式

public class pay {

private int ram = 1999;
private int lcd = 3999;
private int mouse = 699;
private int hdd = 999;
private String name;
private int ramS, lcdS, mouseS, hddS, sum;

public pay(String name, int ramS, int lcdS, int mouseS, int hddS) {
this.name = name;
//如果數量>0，才可以放進來(確保資料正確)
if (ramS > 0 && lcdS > 0 && mouseS > 0 && hddS > 0) {
this.ramS = ramS;
this.lcdS = lcdS;
this.mouseS = mouseS;
this.hddS = hddS;
}
sum = ram * ramS + lcd * lcdS + mouse * mouseS + hdd * hddS; //計算購買總金額
if (sum > 4000) {
sum = (int) (sum * 0.96);//如果總金額大於4000，sum打96折
}
}

public void setRamS(int ramS) {
this.ramS = ramS;
}

public void setLcdS(int lcdS) {
this.lcdS = lcdS;
}

public void setMouseS(int mouseS) {
this.mouseS = mouseS;
}

public void setHddS(int hddS) {
this.hddS = hddS;
}

public void setSum(int sum) {
this.sum = sum;
}

public int getRamS() {
return ramS;
}

public int getLcdS() {
return lcdS;
}

public int getMouseS() {
return mouseS;
}

public int getHddS() {
return hddS;
}

public int getSum() {
return sum;
}

public void member(int sum) {
//設計如果是會員，再打95折的方法
this.sum = (int) (sum * 0.95);
}

public String show() {
return “姓名：” + name
+ “\n螢幕：” + lcd * lcdS
+ “\n硬碟：” + hdd * hddS
+ “\n滑鼠：” + mouse * mouseS
+ “\n記憶體：” + ram * ramS
+ “\n總金額：” + sum;
}

}

• [UI]

public class payUI2 extends javax.swing.JFrame {

public payUI2() {
initComponents();
}

@SuppressWarnings(“unchecked”)
// <editor-fold defaultstate=”collapsed” desc=”Generated Code”>
private void initComponents() {

jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
jLabel5 = new javax.swing.JLabel();
name = new javax.swing.JTextField();
mouse = new javax.swing.JTextField();
ram = new javax.swing.JTextField();
hdd = new javax.swing.JTextField();
member = new javax.swing.JCheckBox();
cal = new javax.swing.JButton();
jScrollPane1 = new javax.swing.JScrollPane();
ans = new javax.swing.JTextArea();
jLabel6 = new javax.swing.JLabel();
lcd = new javax.swing.JTextField();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

jPanel1.setBackground(new java.awt.Color(204, 204, 204));

jLabel1.setFont(new java.awt.Font(“微軟正黑體”, 1, 24)); // NOI18N
jLabel1.setText(“來來3C商店付款系統”);

jLabel2.setFont(new java.awt.Font(“微軟正黑體”, 0, 18)); // NOI18N
jLabel2.setText(“姓名：”);

jLabel3.setFont(new java.awt.Font(“微軟正黑體”, 0, 18)); // NOI18N
jLabel3.setText(“滑鼠：”);

jLabel4.setFont(new java.awt.Font(“微軟正黑體”, 0, 18)); // NOI18N
jLabel4.setText(“記憶體：”);

jLabel5.setFont(new java.awt.Font(“微軟正黑體”, 0, 18)); // NOI18N
jLabel5.setText(“硬碟：”);

member.setFont(new java.awt.Font(“微軟正黑體”, 0, 18)); // NOI18N
member.setText(“會員”);

cal.setFont(new java.awt.Font(“微軟正黑體”, 0, 18)); // NOI18N
cal.setText(“計算”);
cal.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
calMouseClicked(evt);
}
});

ans.setColumns(20);
ans.setRows(5);
jScrollPane1.setViewportView(ans);

jLabel6.setFont(new java.awt.Font(“微軟正黑體”, 0, 18)); // NOI18N
jLabel6.setText(“螢幕：”);

javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
.addContainerGap(88, Short.MAX_VALUE)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(member)
.addComponent(jLabel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING, false)
.addComponent(cal, javax.swing.GroupLayout.Alignment.LEADING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel2)
.addComponent(jLabel6))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(name, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(lcd, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel5)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(hdd, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(mouse, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addComponent(jLabel4)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(ram, javax.swing.GroupLayout.PREFERRED_SIZE, 100, javax.swing.GroupLayout.PREFERRED_SIZE)))
.addComponent(jScrollPane1))
.addGap(79, 79, 79))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 20, Short.MAX_VALUE)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(name, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel2, javax.swing.GroupLayout.Alignment.TRAILING))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jLabel6)
.addComponent(lcd, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel5)
.addComponent(hdd, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel3)
.addComponent(mouse, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel4)
.addComponent(ram, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(member)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(cal, javax.swing.GroupLayout.PREFERRED_SIZE, 49, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 135, javax.swing.GroupLayout.PREFERRED_SIZE))
);

javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);

pack();
}// </editor-fold>

private void calMouseClicked(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
int ramN, lcdN, mouseN, hddN;
String Name = name.getText();

ramN = Integer.parseInt(ram.getText());
lcdN = Integer.parseInt(lcd.getText());
mouseN = Integer.parseInt(mouse.getText());
hddN = Integer.parseInt(hdd.getText());

pay p = new pay(Name, ramN, lcdN, mouseN, hddN);

if (member.isSelected()) {
p.member(p.getSum());
}

ans.setText(p.show());

}

/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate=”collapsed” desc=” Look and feel setting code (optional) “>
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if (“Nimbus”.equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(payUI2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(payUI2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(payUI2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(payUI2.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>

/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new payUI2().setVisible(true);
}
});
}

// Variables declaration — do not modify
private javax.swing.JTextArea ans;
private javax.swing.JButton cal;
private javax.swing.JTextField hdd;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel6;
private javax.swing.JPanel jPanel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JTextField lcd;
private javax.swing.JCheckBox member;
private javax.swing.JTextField mouse;
private javax.swing.JTextField name;
private javax.swing.JTextField ram;
// End of variables declaration
}

• 當按下送出之後，姓名、品項、價格都會直接顯示在底下的黃色框框中

(請參考UI打的粗體字程式碼)

• 當將會員打勾之後，會重新計算總金額(打95折)