我正在尝试使用Student类和主类中的几个方法来创建一个简单的程序（列表，创建和写入文件，del项目，添加项目，搜索和排序项目）。 它运行良好但是， 我希望以更“干净的方式”或“面向对象”的方式拥有它。 任何想法如何改善它？ 下面是代码。 谢谢你的任何建议！
public class SimpleDB {
static FileWriter fstream;
static BufferedWriter out;
public static ArrayList<Student> students;
static Scanner menuSc;
static File file;
static Scanner nameOfFile;
static FileWriter wr;
static Scanner addNameAndEmail;
static Scanner sort;
static Scanner search;
public static void createWriteToFile() {
try {
String aktDir = System.getProperty("user.dir");// the directory where app (java) was started (working dir)
//System.out.println("Aktual dir>" + aktDir);
System.out.println("Please enter name of file ...\n");
nameOfFile = new Scanner(System.in);
String nof = nameOfFile.nextLine();
file = new File(nof);
if (!file.exists()) {
System.out.println("Creating new file : " + nof);
}
try { //create new file
file.createNewFile();
} catch (IOException ex) {
Logger.getLogger(SimpleDB.class.getName()).log(Level.SEVERE, null, ex);
}
System.out.println("Writing to file " + nof);
try {
wr = new FileWriter(nof);
} catch (IOException ex) {
Logger.getLogger(SimpleDB.class.getName()).log(Level.SEVERE, null, ex);
}
for (Student stu : students) {
try {
wr.write(stu.toString());
} catch (IOException ex) {
Logger.getLogger(SimpleDB.class.getName()).log(Level.SEVERE, null, ex);
}
}
wr.close();
} catch (IOException ex) {
Logger.getLogger(SimpleDB.class.getName()).log(Level.SEVERE, null, ex);
}
}
public static void sort() {
boolean b = true;
while (true) {
System.out.println("Sorting> by name: type N, by email: type E, for exit: type X \n");
sort = new Scanner(System.in);
String s = sort.nextLine();
switch (s) {
case "N":
System.out.println("Sorting by name....: \n");
students.sort((Student s1, Student s2) -> {
return s1.getName().compareToIgnoreCase(s2.getName());
});
System.out.println("Sorted by name> \n" + students);
break;
case "E":
System.out.println("Sorting by mail....: \n");
students.sort((Student s1, Student s2) -> {
return s1.getEmail().compareToIgnoreCase(s2.getEmail());
});
System.out.println("Sorted list> \n" + students);
break;
case "X":
System.out.println("Returning to main menu...");
b = false;
return;
default:
System.out.println("Please enter correct choice! ");
break;
}
}
}
public static void search() {
System.out.println("Enter a name you want to search> \n");
search = new Scanner(System.in);
boolean bol = false;
String se = search.next();
for (int i = 0; i < students.size(); i++) {
if (se.equalsIgnoreCase(students.get(i).getName())) {
bol = true;
break;
}
}
if (bol) {
System.out.println("found");
} else {
System.out.println("not found");
}
}
private static void add() {
addNameAndEmail = new Scanner(System.in);
System.out.println("Please enter a name: ");
String n = addNameAndEmail.nextLine();
System.out.println("Please enter an email: ");
String e = addNameAndEmail.nextLine();
students.add(new Student(n, e));
System.out.println("\n" + "new student " + students);
}
public static void list() {
System.out.println("List of Students> ");
String l = null;
for (Student stu : students) {
System.out.println(stu);
}
}
public static char menu() {
System.out.println(""
+ " 'A' list, 'B' add, 'C' save to file, 'D' search, 'E' sort data, 'F' exit from program > ");
menuSc = new Scanner(System.in);
String c = menuSc.nextLine();
if (c.isEmpty()) {
return ' ';
} //Files.copy(null, null, options)
return c.toUpperCase().charAt(0);
}
public static void main(String[] args) throws IOException {
// some students added
students = new ArrayList<>();
students.add(new Student("alan", "alan@gmail.com"));
students.add(new Student("michael", "michael@gmail.com"));
students.add(new Student("peter", "peter@gmail.com"));
students.add(new Student("andrew", "andrew@gmail.com"));
boolean a = true;
while (a = true) {
char c = menu();
switch (c) {
case 'A':
list();
break;
case 'B':
add();
break;
case 'C':
createWriteToFile();
break;
case 'E':
sort();
break;
case 'D':
search();
break;
case 'F':
System.out.println("Good Bye!");
a = false;
return;
}
}
}
}
答案 0 :(得分：2)
如前所述，您可能想在codereview.stackexchange.com上提出这个问题，因为它更适合您的问题。
在高级概述中，您应该创建一些Object！因此OOP。
Student
StudentService
Main
在此处添加学生，将其放入列表中，并将列表提供给StudentService班级实例。然后，您可以根据需要调用studentService对象的方法。
这是一个简单的例子，你可以随意扩展它。