Update

src/finalexam/Database/DataOutput.java

@@ -0,0 +1,81 @@
+package finalexam.Database;
+
+import java.io.BufferedWriter;
+import java.io.File;
+import java.io.FileWriter;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.util.Scanner;
+
+import jxl.Workbook;
+import jxl.write.Label;
+import jxl.write.WritableSheet;
+import jxl.write.WritableWorkbook;
+
+public class DataOutput {
+    private static final String DBDRIVER = "com.mysql.cj.jdbc.Driver";
+    private static final String DBURL = "jdbc:mysql://localhost:3306/xiaoshou?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=GMT";
+
+    public static void main(String[] args) throws Exception {
+        Class.forName(DBDRIVER);
+        Connection conn = DriverManager.getConnection(DBURL);
+        PreparedStatement pstmt = null;
+        ResultSet rs = null;
+        Scanner sc = new Scanner(System.in);
+        System.out.println("===****超市商品管理维护====");
+        System.out.println("1、导出商品信息至excel");
+        System.out.println("2、导出商品信息至文本文件");
+        System.out.println("3、返回主菜单");
+        System.out.print("请选择（1-3）：");
+        int choice = sc.nextInt();
+        switch (choice) {
+            case 1:
+                WritableWorkbook workbook = Workbook.createWorkbook(new File("商品导出.xls"));
+                WritableSheet sheet = workbook.createSheet("商品信息", 0);
+                sheet.addCell(new Label(0, 0, "条码"));
+                sheet.addCell(new Label(1, 0, "名称"));
+                sheet.addCell(new Label(2, 0, "单价"));
+                sheet.addCell(new Label(3, 0, "供应商"));
+                pstmt = conn.prepareStatement("SELECT * FROM t_shangping");
+                rs = pstmt.executeQuery();
+                int row = 1;
+                while (rs.next()) {
+                    sheet.addCell(new Label(0, row, rs.getString("tiaoma")));
+                    sheet.addCell(new Label(1, row, rs.getString("mingcheng")));
+                    sheet.addCell(new Label(2, row, rs.getString("danjia")));
+                    sheet.addCell(new Label(3, row, rs.getString("gongyingshang")));
+                    row++;
+                }
+                workbook.write();
+                workbook.close();
+                System.out.println("成功导出" + (row - 1) + "条商品数据到excel中");
+                break;
+            case 2:
+                FileWriter fw = new FileWriter("商品导出.txt");
+                BufferedWriter bw = new BufferedWriter(fw);
+                bw.write("条码\t名称\t单价\t供应商\n");
+                pstmt = conn.prepareStatement("SELECT * FROM t_shangping");
+                rs = pstmt.executeQuery();
+                while (rs.next()) {
+                    bw.write(rs.getString("tiaoma") + "\t");
+                    bw.write(rs.getString("mingcheng") + "\t");
+                    bw.write(rs.getString("danjia") + "\t");
+                    bw.write(rs.getString("gongyingshang") + "\n");
+                }
+                bw.close();
+                fw.close();
+                System.out.println("成功导出XXX条商品数据到txt中");
+                break;
+            case 3:
+                break;
+            default:
+                System.out.println("无效的选择，请重新选择（1-3）：");
+                break;
+        }
+        rs.close();
+        pstmt.close();
+        conn.close();
+    }
+}

src/finalexam/StandardIO/DateCalculation.java

@@ -3,7 +3,7 @@ package finalexam.StandardIO;
 import java.util.Scanner;
 
 public class DateCalculation {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         Scanner sc = new Scanner(System.in);
         String s = sc.nextLine();
         String[] arr = s.split("[-]");
@@ -14,9 +14,8 @@ public class DateCalculation {
         if (isLeapYear(year))
             days[2] = 28;
         int ans = day;
-        for (int i = 1; i < month; i++) {
+        for (int i = 1; i < month; i++)
             ans += days[i];
-        }
         System.out.println(ans);
     }
 

src/finalexam/StandardIO/DateFormatOutput.java

@@ -3,7 +3,7 @@ package finalexam.StandardIO;
 import java.util.Scanner;
 
 public class DateFormatOutput {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         char[] num = { '〇', '一', '二', '三', '四', '五', '六', '七', '八', '九' };
         Scanner sc = new Scanner(System.in);
         String s = sc.next();

src/finalexam/StandardIO/Encryption.java

@@ -3,7 +3,7 @@ package finalexam.StandardIO;
 import java.util.Scanner;
 
 public class Encryption {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception{
         Scanner sc = new Scanner(System.in);
         String s = sc.nextLine();
         String k = sc.nextLine();

src/finalexam/StandardIO/Expressions.java

@@ -3,7 +3,7 @@ package finalexam.StandardIO;
 import java.util.Scanner;
 
 public class Expressions {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception{
         Scanner sc = new Scanner(System.in);
         String s = sc.nextLine();
         String[] arr = s.split("[\\(\\),]");

src/finalexam/StandardIO/FileIO.java

@@ -2,14 +2,12 @@ package finalexam.StandardIO;
 
 import java.io.File;
 import java.io.FileWriter;
-import java.io.IOException;
 import java.util.Scanner;
 
 public class FileIO {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         File fQ = new File("question.txt");
         File fA = new File("answer.txt");
-        try {
         Scanner sc = new Scanner(fQ);
         FileWriter fw = new FileWriter(fA);
         while (sc.hasNextLine()) {
@@ -36,8 +34,5 @@ public class FileIO {
             fw.write(s + "=" + ans + '\n');
         }
         fw.close();
-        } catch (IOException e) {
-            e.printStackTrace();
-        }
     }
 }

src/finalexam/StandardIO/PrimeNumbers.java

@@ -4,14 +4,13 @@ import java.util.ArrayList;
 import java.util.Scanner;
 
 public class PrimeNumbers {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         Scanner sc = new Scanner(System.in);
         int n = sc.nextInt();
         ArrayList<Integer> primes = new ArrayList<>();
-        for (int i = 2; i < n; i++) {
+        for (int i = 2; i < n; i++)
             if (isPrime(i))
                 primes.add(i);
-        }
         System.out.print(primes.size() + "(分别是");
         for (int i = 0; i < primes.size(); i++) {
             System.out.print(primes.get(i));
@@ -24,10 +23,9 @@ public class PrimeNumbers {
     static boolean isPrime(int n) {
         if (n <= 1)
             return false;
-        for (int i = 2; i <= Math.sqrt(n); i++) {
+        for (int i = 2; i <= Math.sqrt(n); i++)
             if (n % i == 0)
                 return false;
-        }
         return true;
     }
 }

src/finalexam/StandardIO/SecurePasswordSpecification.java

@@ -3,7 +3,7 @@ package finalexam.StandardIO;
 import java.util.Scanner;
 
 public class SecurePasswordSpecification {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         Scanner sc = new Scanner(System.in);
         String s = sc.next();
         System.out.println(isSafePassword(s) ? "success" : "fail");

src/finalexam/StandardIO/StatisticsOfProducts.java

@@ -33,7 +33,7 @@ class Goods {
 }
 
 public class StatisticsOfProducts {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         Scanner sc = new Scanner(System.in);
         Goods[] goods = new Goods[5];
         double sum = 0;

src/finalexam/StandardIO/StringInitialization.java

@@ -3,17 +3,16 @@ package finalexam.StandardIO;
 import java.util.Scanner;
 
 public class StringInitialization {
-    public static void main(String[] var0) {
+    public static void main(String[] args) throws Exception {
         Scanner sc = new Scanner(System.in);
         String s = sc.nextLine();
         char[] c = s.toCharArray();
         c[0] = Character.toUpperCase(c[0]);
-        for (int i = 1; i < c.length; i++) {
+        for (int i = 1; i < c.length; i++) 
             if (c[i - 1] != ',' && c[i - 1] != ' ')
                 c[i] = Character.toLowerCase(c[i]);
             else
                 c[i] = Character.toUpperCase(c[i]);
-        }
         System.out.println(new String(c));
     }
 }

src/finalexam/StandardIO/SumInReverseOrder.java

@@ -3,7 +3,7 @@ package finalexam.StandardIO;
 import java.util.Scanner;
 
 public class SumInReverseOrder {
-    public static void main(String[] args) {
+    public static void main(String[] args) throws Exception {
         Scanner sc = new Scanner(System.in);
         int n1 = sc.nextInt();
         int n2 = sc.nextInt();