英文:
Index 0 out of bounds for length 0 at university_info.UniversityDriver.main(UniversityDriver.java:39)
问题
以下是您提供的代码的翻译部分：
我在尝试运行我的程序时遇到了这个错误。有人可以帮我找出问题吗？> 在线程“main”中的异常java.lang.ArrayIndexOutOfBoundsException：索引0超出了长度0的界限> 位于university_info.UniversityDriver.main(UniversityDriver.java:39)我的代码：UniversityDriver.java包 university_info;导入 java.io.FileInputStream;导入 java.io.FileNotFoundException;导入 java.io.FileOutputStream;导入 java.io.IOException;导入 java.io.ObjectInputStream;导入 java.io.ObjectOutputStream;导入 java.util.ArrayList;导入 java.util.Scanner;公共类 UniversityDriver {公共静态无效 main(String[] args) {// TODO 自动生成的方法存根大学 u_city = new University("hero university","好好教学");System.out.println("欢迎来到" + u_city.universityName + "大学");System.out.println(u_city.motto);// 在启动时从外部文件检索数据...ArrayList<Person> al = new ArrayList<Person>();尝试 {FileInputStream fis = new FileInputStream("fileName.txt");ObjectInputStream ois = new ObjectInputStream(fis);al = (ArrayList<Person>) ois.readObject();ois.close();} 捕获 (FileNotFoundException ex) {System.out.println("文件未找到异常");} 捕获 (IOException ex) {ex.printStackTrace();} 捕获 (ClassNotFoundException ex) {}对象[] 数组 = 新对象[al.size()];array = al.toArray(array);对于 (int i = 0; i <= array.length; i++) {u_city.people[i] = (Person) array[i];}System.out.println("您想要做什么？");System.out.println("输入'雇佣'以雇佣新的教职员工。 ");System.out.println("输入'录取'以录取新的学生 ");System.out.println("输入'查找学生'以列出有关学生的信息");System.out.println("输入'查找教职员工'以列出有关教职员工的信息");System.out.println("输入'列出学生'以列出所有学生的姓名。");System.out.println("输入'列出教职员工'以列出教职员工的姓名");System.out.println("输入'退出'以结束此程序并保存数据");//-------------------->扫描器 在 = 新扫描器(System.in);布尔值 运行 = 真;当 (运行) {字符串 s = 在.nextLine();如果 (s.equals("退出")) {运行 = 假;// 将数据保存在外部文件中尝试 {FileOutputStream fos = new FileOutputStream("fileName.txt");ObjectOutputStream oos = new ObjectOutputStream(fos);oos.writeObject(u_city.people);oos.close();} 捕获 (IOException ex) {ex.printStackTrace();}}如果 (s.equals("雇佣")) {u_city.hire();}如果 (s.equals("录取")) {u_city.admit();}如果 (s.equals("查找学生")) {System.out.println("学生的名字是什么？");字符串 fn = 在.nextLine();System.out.println("学生的姓氏是什么？");字符串 ln = 在.nextLine();学生 temp = u_city.findStudent(fn, ln);如果 (temp == null) {System.out.println("未找到学生");} 否则 {temp.Details();}}如果 (s.equals("查找教职员工")) {System.out.println("教职员工的名字是什么？");字符串 fn = 在.nextLine();System.out.println("教职员工的姓氏是什么？");字符串 ln = 在.nextLine();教职员工 temp = u_city.findFaculty(fn, ln);如果 (temp == null) {System.out.println("未找到教职员工");}}如果 (s.equals("列出学生")) {人[] temp = u_city.getStudents();对于 (int i = 0; i <= temp.length; i++) {System.out.println(temp[i].firstName + " " + temp[i].lastName);}}如果 (s.equals("列出教职员工")) {人[] temp = u_city.getFaculty();对于 (int i = 0; i <= temp.length; i++) {System.out.println(temp[i].firstName + " " + temp[i].lastName);}}}}}Faculty.java包 university_info;公共类 Faculty 扩展 Person {字符串[] 课程; // 教职员工教授的课程公共教职员工(String first, String last, int m, int d, int y, String[] course, 布尔值 bol) {这个.课程 = 课程; //----------->这个.firstName = first;这个.lastName = last;这个.monthBirth = m;这个.dayBirth = d;这个.yearBirth = y;这个.student_or_faculty = bol;}公共无效 详情_教职员工() {System.out.println("学生：" + 这个.firstName + " " + 这个.lastName);System.out.println("出生日期： " + 这个.dayBirth + "/" + 这个.monthBirth + "/" + 这个.yearBirth);System.out.println("课程： ");对于 (int i = 0; i <= 课程.length; i++) {System.out.println(课程[i]);}}}Person.java包 university_info;公共类 Person {字符串 firstName;字符串 lastName;整数 monthBirth;整数 dayBirth;整数 yearBirth;布尔值 student_or_faculty; // 学生为真，教职员工为假公共人() {} //<details><summary>英文:</summary>I am getting this error when trying to run my program.Can someone help me figure it out?> Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0> at university_info.UniversityDriver.main(UniversityDriver.java:39)My code:UniversityDriver.javapackage university_info;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.util.ArrayList;import java.util.Scanner;public class UniversityDriver{public static void main(String[] args) {// TODO Auto-generated method stubUniversity u_city=new University("hero university","Teach well");System.out.println("Welcome to "+u_city.universityName+" Univercity");System.out.println(u_city.motto);// retrieving data from external file on startup.....ArrayList<Person> al=new ArrayList<Person>();try{FileInputStream fis = new FileInputStream("fileName.txt");ObjectInputStream ois = new ObjectInputStream(fis);al = (ArrayList<Person>)ois.readObject();ois.close();}catch(FileNotFoundException ex){System.out.println("File not found exception");}catch(IOException ex){ex.printStackTrace();}catch(ClassNotFoundException ex){}Object[] array=new Object[al.size()];array=al.toArray(array);for(int i=0;i<=array.length;i++){u_city.people[i]=(Person)array[i];}System.out.println("What would you like to do");System.out.println("Enter 'hire' to hire a new faculty member. ");System.out.println("Enter 'admit' to admit a new student ");System.out.println("Enter 'find student' to list information about a student");System.out.println("Enter 'find faculty' to list information about a faculty member");System.out.println("Enter 'list students' to list the names of all students.");System.out.println("Enter 'list faculty' to list the names of faculty members");System.out.println("Enter 'quit' to end this program and save data");//-------------------->Scanner in =new Scanner(System.in);boolean run= true;while(run){String s= in.nextLine();if(s.equals("quit")){run=false;//save data in extenal filetry{FileOutputStream fos = new FileOutputStream("fileName.txt");ObjectOutputStream oos = new ObjectOutputStream(fos);oos.writeObject(u_city.people);oos.close();}catch(IOException ex){ex.printStackTrace();}}if(s.equals("hire")){u_city.hire();}if(s.equals("admit")){u_city.admit();}if(s.equals("find_student")){System.out.println("What is the student's first name?");String fn=in.nextLine();System.out.println("What is the student's last name?");String ln=in.nextLine();Student temp=u_city.findStudent(fn, ln);if(temp==null){System.out.println("Student not found");}else{temp.Details();}}if(s.equals("find_faculty")){System.out.println("What is the faculty's first name?");String fn=in.nextLine();System.out.println("What is the faculty's last name?");String ln=in.nextLine();Faculty temp=u_city.findFaculty(fn, ln);if(temp==null){System.out.println("faculty not found");}}if(s.equals("list_student")){Person[] temp= u_city.getStudents();for(int i=0;i<=temp.length;i++){System.out.println(temp[i].firstName+" "+temp[i].lastName);}}if(s.equals("list_faculty")){Person[] temp= u_city.getFaculty();for(int i=0;i<=temp.length;i++){System.out.println(temp[i].firstName+" "+temp[i].lastName);}}}}}Faculty.javapackage university_info;public class Faculty extends Person {String[] courses; // courses that faculty member teachespublic Faculty(String first,String last,int m,int d,int y,String[] course,boolean bol){this.courses=course; //----------->this.firstName=first;this.lastName=last;this.monthBirth=m;this.dayBirth=d;this.yearBirth=y;this.student_or_faculty=bol;}public void Details_Faculty(){System.out.println("Student:"+ this.firstName +" "+ this.lastName);System.out.println("DOB: "+ this.dayBirth+"/"+this.monthBirth+"/"+this.yearBirth);System.out.println("Courses: ");for(int i=0;i<=courses.length;i++){System.out.println(courses[i]);}}}Person.javapackage university_info;public class Person {String firstName;String lastName;int monthBirth;int dayBirth;int yearBirth;boolean student_or_faculty; // true for student and false for facultypublic Person(){} //must have a constructor}School.javapackage university_info;public interface School {Student findStudent(String fn,String ln);Faculty findFaculty(String fn,String ln);Faculty hire();Student admit();Person[] getAllPersons();String[] getAllMajors();String[] getAllCourses();Person[] getStudents();Person[] getFaculty();}Student.javapackage university_info;public class Student extends Person {String major;public Student(String first,String last,int m,int d,int y,String major,boolean bol){this.major=major;this.firstName=first;this.lastName=last;this.monthBirth=m;this.dayBirth=d;this.yearBirth=y;this.student_or_faculty=bol;} // must have a constructorpublic void Details(){System.out.println("Student:"+ this.firstName +" "+ this.lastName);System.out.println("DOB: "+ this.dayBirth+"/"+this.monthBirth+"/"+this.yearBirth);System.out.println("Major: "+this.major);}}University.javapackage university_info;import java.util.Scanner;public class University implements School {int MAX_SIZE= 500;String universityName;String motto;Person[] people;String[] majors;String[] courses;public University(String u_Name,String u_motto){this.universityName=u_Name;this.motto=u_motto;people=new Person[MAX_SIZE];majors=new String[4];majors[0]= "Hardware Architecture";majors[1]= "Information Analytics";majors[2]= "Quantum Computing";majors[3]= "Undecided";courses=new String[12];courses[0]="Computers";courses[1]="Advance Physics";courses[2]="Quantum Entanglement";courses[3]="Parallel Programming";courses[4]="Advance Algorithums";courses[5]="FPGA Programming";courses[6]="Hardware Design";courses[7]="Embedded Systems";courses[8]="Signal Processing";courses[9]="Artificial Intelligence";courses[10]="Bayesian Logic";courses[11]="Probablity";}public Student findStudent(String fn, String ln) {// TODO Auto-generated method stubfor(int i=0;i<=people.length;i++){if(people[i].firstName.equals(fn)&& people[i].lastName.equals(ln));return (Student)people[i];}return null;}public Faculty findFaculty(String fn, String ln) {// TODO Auto-generated method stubfor(int i=0;i<=people.length;i++){if(people[i].firstName.equals(fn)&& people[i].lastName.equals(ln));return (Faculty)people[i];}return null;}public Faculty hire() {// TODO Auto-generated method stubScanner in =new Scanner(System.in);String s= in.nextLine();System.out.println("You entered string "+s);System.out.println("What is the person's first name?");String f_name= in.nextLine();System.out.println("What is the person's last name?");String l_name= in.nextLine();System.out.println("What is the person's month of birth?");int m= in.nextInt();System.out.println("What is the person's day of birth?");int d= in.nextInt();System.out.println("What is the person's year of birth?");int y= in.nextInt();String[] c=new String[20];// max 20 courses can be assigned to facultyint i=0;boolean condition=true;while(condition) {System.out.println("Assign a course to this Faculty enter 'done' if there are no other courses?");String course= in.nextLine();if(!course.equals("done")) {c[i]=course;i++;}condition=false;}boolean b=false;Faculty temp=new Faculty(f_name,l_name,m,d,y,c,b);return temp;}public Student admit() {// TODO Auto-generated method stubScanner in =new Scanner(System.in);String s= in.nextLine();System.out.println("You entered string "+s);System.out.println("What is the person's first name?");String f_name= in.nextLine();System.out.println("What is the person's last name?");String l_name= in.nextLine();System.out.println("What is the person's month of birth?");int m= in.nextInt();System.out.println("What is the person's day of birth?");int d= in.nextInt();System.out.println("What is the person's year of birth?");int y= in.nextInt();System.out.println("What is the person's major?");String major= in.nextLine();boolean b=true;Student temp=new Student(f_name,l_name,m,d,y,major,b);return temp;}public Person[] getAllPersons() {// TODO Auto-generated method stubreturn this.people;}public String[] getAllMajors() {// TODO Auto-generated method stubreturn this.majors;}public String[] getAllCourses() {// TODO Auto-generated method stubreturn this.courses;}public Person[] getStudents() {// TODO Auto-generated method stubPerson[] temp=new Person[MAX_SIZE];for(int i=0;i<=MAX_SIZE;i++){if(people[i].student_or_faculty == true){temp[i]=people[i];}}return temp;}public Person[] getFaculty() {// TODO Auto-generated method stubPerson[] temp=new Person[MAX_SIZE];for(int i=0;i<=MAX_SIZE;i++){if(people[i].student_or_faculty == false){temp[i]=people[i];}}return temp;}}</details># 答案1**得分**: 1将此部分更改为：```javafor (int i = 0; i < array.length; i++) {u_city.people[i] = (Person) array[i];}
将解决此问题。循环不能超过数组的大小，而且由于索引 i 从 0 开始，最大索引号可以是数组大小减一。
希望这有所帮助。
英文:
Changing this part:
for (int i = 0; i <= array.length; i++) {u_city.people[i] = (Person) array[i];}
to
for (int i = 0; i < array.length; i++) {u_city.people[i] = (Person) array[i];}
will resolve the issue. The loop cannot exceed the size of array, and since the index i starts from 0, maximum index number could be array's size minus one.
Hope this helps out.
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