StudentManagerPlus.java
package ly.com;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;
public class StudentManagerPlus {
public static void main(String[] args) throws IOException {
addMainPage("array.txt");
return;
}
public static void addMainPage(String fileName) throws IOException {
while (true) {
System.out.println("------欢迎来到学生信息管理系统------");
System.out.println("1.查看所有学生信息");
System.out.println("2.添加学生");
System.out.println("3.删除学生");
System.out.println("4.修改学生");
System.out.println("5.退出");
System.out.println("请输入序号选择");
Scanner sc = new Scanner(System.in);
String inputStr = sc.nextLine();
switch (inputStr) {
case "1": // 1.查看所有学生信息
getAllStudent(fileName);
break;
case "2": // 2.添加学生
addStudent(fileName);
break;
case "3": // 3.删除学生
removeStudent(fileName);
break;
case "4": // 4.修改学生信息
modifyStudent(fileName);
break;
case "5": // 5.退出
default:
System.out.println("谢谢使用！");
System.exit(0);
break;
}
}
}
public static void readDataFromFile(ArrayList<Student> array, String fileName) throws IOException {
BufferedReader br = new BufferedReader(new FileReader(fileName));
String line;
while (null != (line = br.readLine())) {
String[] strArr = line.split("\t");
Student stu = new Student(strArr[0], strArr[1], strArr[2], strArr[3]);
array.add(stu);
// System.out.println(line);
}
br.close();
return;
}
public static void writeDataToFile(ArrayList<Student> array, String fileName) throws IOException {
BufferedWriter bw = new BufferedWriter(new FileWriter(fileName));
for (int i = 0; i < array.size(); i++) {
Student stu = array.get(i);
StringBuffer bs = new StringBuffer();
bs.append(stu.getId()).append("\t");
bs.append(stu.getName()).append("\t");
bs.append(stu.getAge()).append("\t");
bs.append(stu.getAddress()).append("\t");
bw.write(bs.toString());
bw.newLine();
bw.flush();
}
bw.close();
return;
}
public static void getAllStudent(String fileName) throws IOException {
ArrayList<Student> array = new ArrayList<Student>();
readDataFromFile(array, fileName);
if (0 == array.size()) {
System.out.println(fileName + "文件中没有学生信息");
return;
}
System.out.println("学号\t姓名\t年龄\t住址");
for (int i = 0; i < array.size(); i++) {
Student stu = array.get(i);
System.out.println(stu.getId() + "\t" + stu.getName() + "\t" + stu.getAge() + "\t" + stu.getAddress());
}
return;
}
public static void addStudent(String fileName) throws IOException {
ArrayList<Student> array = new ArrayList<Student>();
readDataFromFile(array, fileName);
Scanner sc = new Scanner(System.in);
System.out.println("请输入需要添加的学生学号");
String strId = sc.nextLine();
if (0 != array.size()) {
while (true) {
int i = 0;
for (; i < array.size(); i++) {
Student stu = array.get(i);
if (strId.equals(stu.getId())) {
System.out.println("该学号已被占用，请重新输入添加的学生学号");
strId = sc.nextLine();
break;
}
}
if (i == array.size()) {
break;
}
}
}
System.out.println("请输入学生姓名"); String strName = sc.nextLine();
System.out.println("请输入学生年龄"); String strAge = sc.nextLine();
System.out.println("请输入学生住址"); String strAddress = sc.nextLine();
//sc.close();
Student newStu = new Student(strId, strName, strAge, strAddress);
array.add(newStu);
writeDataToFile(array, fileName);
System.out.println("添加学生成功");
return;
}
public static void removeStudent(String fileName) throws IOException {
ArrayList<Student> array = new ArrayList<Student>();
readDataFromFile(array, fileName);
if (0 == array.size()) {
System.out.println("学生信息管理系统中没有学生信息，请重新输入");
return;
}
Scanner sc = new Scanner(System.in);
System.out.println("请输入要删除的学生学号");
String strId = sc.nextLine();
int i = 0;
while (true) {
i = 0;
for (; i < array.size(); i++) {
if (true == strId.equals(array.get(i).getId())) {
break;
}
}
if (i == array.size()) {
System.out.println("未查找到该学生学号，请重新输入需要删除的学生学号");
strId = sc.nextLine();
} else {
break;
}
}
//sc.close();
array.remove(i);
writeDataToFile(array, fileName);
System.out.println("删除学生成功");
return;
}
public static void modifyStudent(String fileName) throws IOException {
ArrayList<Student> array = new ArrayList<Student>();
readDataFromFile(array, fileName);
if (0 == array.size()) {
System.out.println("学生信息系统中没有学生信息，请重新选择");
return;
}
Scanner sc = new Scanner(System.in);
System.out.println("请输入需要修改的学生学号");
String strId = sc.nextLine();
int i = 0;
while (true) {
i = 0;
for (; i < array.size(); i++) {
if (true == strId.equals(array.get(i).getId())) {
break;
}
}
if (i == array.size()) {
System.out.println("未查找到该学生学号，请重新输入需要修改的学生学号");
strId = sc.nextLine();
} else {
break;
}
}
System.out.println("请输入新学生学号"); String newId = sc.nextLine();
System.out.println("请输入新学生姓名"); String newName = sc.nextLine();
System.out.println("请输入新学生年龄"); String newAge = sc.nextLine();
System.out.println("请输入新学生住址"); String newAddress = sc.nextLine();
//sc.close();
Student stu = new Student(newId, newName, newAge, newAddress);
array.set(i, stu);
writeDataToFile(array, fileName);
System.out.println("修改学生成功");
return;
}
}
小记：
昨晚为了消除Eclipse中的警告，添加了sc.close();，今晚运行的时候出问题了。实践证明，不能加这一句。
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