ADD file via upload

FileManager.java

@@ -0,0 +1,57 @@
+// FileManager.java
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+public class FileManager {
+  public static final String ROOT_PATH = "./试卷/";
+
+  public void savePaper(User user, List<String> questions) throws IOException {
+    String userDirectory = ROOT_PATH + user.getUsername();
+    Path userPath = Paths.get(userDirectory);
+    if (!Files.exists(userPath)) {
+      Files.createDirectories(userPath);
+    }
+
+    String fileName = LocalDateTime.now().format(DateTimeFormatter.ofPattern("yyyy-MM-dd-HH-mm-ss")) + ".txt";
+    Path filePath = userPath.resolve(fileName);
+    try (PrintWriter writer = new PrintWriter(new FileWriter(filePath.toFile(), StandardCharsets.UTF_8))) {
+      for (int index = 0; index < questions.size(); index++) {
+        writer.printf("%d. %s%n%n", index + 1, questions.get(index));
+      }
+    }
+  }
+
+  public boolean checkQuestion(String question, User user) throws IOException {
+    String userDirectory = ROOT_PATH + user.getUsername();
+    Path userPath = Paths.get(userDirectory);
+    if (!Files.exists(userPath)) {
+      return true;
+    } else {
+      File directory = new File("./试卷/" + user.getUsername());
+      File[] files = directory.listFiles();
+      if (files != null) {
+        for (File file : files) {
+          for (String line : Files.readAllLines(file.toPath())) {
+            if (!line.isEmpty()) {
+              line = line.replaceFirst("^\\d+\\.\\s*", "");
+              if (line.equals(question)) {
+                System.out.println("有道一样的题");
+                return false;
+              }
+            }
+          }
+        }
+      }
+    }
+    return true;
+  }
+}