马凯军201771010116《面向对象程序设计（java）》第三周学习总结

package ssfs;
import java.util.Scanner;
public class erwwq { String year;
String month;
String day;
static String id;
@SuppressWarnings("resource")
public void InputId() {
Scanner sc = new Scanner(System.in);
System.out.println("ID：");
id = sc.nextLine();
}
public void CutId(String id){
year = id.substring(, );
month = id.substring(, );
day = id.substring(, );
}
public String toString(){
return "出身日期：" + year + " - " + month + " - " + day ;
}
public static void main(String[] args) {
erwwq peopleId = new erwwq();
peopleId.InputId();
peopleId.CutId(id);
System.out.println(peopleId.toString());
} }

package ssfs;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner; public class wed { private static ArrayList<Student> studentList = null; public static void StudentsFromFile(String fileName){
File file = new File(fileName);
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(file));
String tempString = null;
while ((tempString = reader.readLine()) != null) {
String str[] = tempString.split(" ");
if(studentList != null && str.length > 1) {
Student student = new Student();
student.setStudentId(str[0]);
studentList.add(student);
}
}
reader.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (reader != null) {
try {
reader.close();
} catch (IOException e1) {
}
}
}
}
public static String findStudentIdByName(String name) {
String studentId = null;
for(Student student : studentList) {
if(student.getName().equals(name)) {
studentId = student.getStudentId();
break;
}
}
return studentId;
}
public static String findStudentNameById(String ID) {
String studentName = null;
for(Student student : studentList) {
if(student.getStudentId().equals(ID)) {
studentName = student.getName();
break;
}
}
return studentName;
}
public static void main(String args[]) {
String path = "D:/studentfile.txt";
studentList = new ArrayList<Student>();
StudentsFromFile(path);
int statu = 1;
System.out.println();
while(statu != 0) {
System.out.println("1:通过姓名查询学生学号");
System.out.println("2:通过学号查询学生姓名");
System.out.println("0:退出");
Scanner scanner = new Scanner(System.in);
statu = scanner.nextInt();
switch(statu) {
case 1:{
System.out.println("请输入学生姓名:");
Scanner scanner1 = new Scanner(System.in);
String name = scanner1.nextLine();
String Id = findStudentIdByName(name);
if(Id != null) {
System.out.println("姓名: "+name+" 学号: "+Id);
}else {
System.out.println("不存在该学生！请重新查找");
} }break;
case 2:{
System.out.println("请输入学生学号:");
Scanner scanner2 = new Scanner(System.in);
String Id = scanner2.nextLine();
String name = findStudentNameById(Id);
if(name != null) {
System.out.println("姓名: "+name+" 学号: "+Id);
}else {
System.out.println("不存在该学生！请重新查找");
}
}break;
case 0:
statu = 0; break;
default:
System.out.println("输入错误");
}
} System.out.println("byebye！");
}
}