Java序列化问题
我有一个写对象的代码:Java序列化问题,java,serialization,Java,Serialization,我有一个写对象的代码: FileOutputStream fileOut = new FileOutputStream("Model.ser"); ObjectOutputStream out = new ObjectOutputStream(fileOut); out.writeObject(this); out.close(); fileOut.close(); 加载对象的代码如下: Model m = null; try { FileInputStream fileIn = ne
FileOutputStream fileOut = new FileOutputStream("Model.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
out.writeObject(this);
out.close();
fileOut.close();
加载对象的代码如下:
Model m = null;
try {
FileInputStream fileIn = new FileInputStream("Model.ser");
ObjectInputStream in = new ObjectInputStream(fileIn);
m = (Model) in.readObject();
in.close();
fileIn.close();
} catch (Exception e) {}
setStudentList(m.getStudentList());
setModuleList(m.getModuleList());
我很确定保存是有效的,因为当我在notepad++中打开文件时,我看到了我保存的大部分数据,但当我加载时,模块列表中没有数据
完整源代码:
import java.io.*;
import java.util.*;
public class Model implements java.io.Serializable {
private Student[] studentList = new Student[0];
private Module[] moduleList = new Module[0];
public void menu() {
while (true) {
System.out.println ("MENU");
System.out.println ("");
System.out.println (" 1 - Run Tests");
System.out.println (" 2 - Add Student");
System.out.println (" 3 - Add Module");
System.out.println (" 4 - Add Student To Module");
System.out.println (" 5 - Save System (Text file)");
System.out.println (" 6 - Load System (Text file)");
System.out.println (" 7 - Save System (Serialized)");
System.out.println (" 8 - Load System (Serialized)");
System.out.println (" 9 - Print Report");
System.out.println ("");
System.out.print ("Enter choice: ");
String input = keyboard.readString();
switch (input) {
case "1" :
runTests();
break;
case "2" :
System.out.print("First Name : ");
String fN = keyboard.readString();
System.out.print("Surname : ");
String sN = keyboard.readString();
System.out.print("Course Code : ");
String c = keyboard.readString();
System.out.print("User ID : ");
String iD = keyboard.readString();
AddStudent(iD, sN, fN, c);
break;
case "3" :
System.out.print("Module Code : ");
String code = keyboard.readString();
String[] temp = new String[0];
AddModule(code,temp);
break;
case "4" :
System.out.print("Module Code : ");
code = keyboard.readString();
Module m = findAModule(code);
if (m != null) {
System.out.print("User ID : ");
iD = keyboard.readString();
Student s = findAStudent(iD);
if (s != null) {
m.addThisStudent(s);
} else {
System.out.println("Student not found");
}
} else {
System.out.println("Module not found");
}
break;
case "5" :
saveToTextFiles();
break;
case "6" :
loadFromTextFiles();
break;
case "7" :
saveSerialized();
break;
case "8" :
break;
case "9" :
printReport();
break;
}
}
}
public void runTests() {
loadFromTextFiles();
saveSerialized();
printReport();
}
public void loadFromTextFiles() {
studentList = new Student[0];
moduleList = new Module[0];
try {
Scanner fileReader = new Scanner(new InputStreamReader(new FileInputStream("students.txt")));
int num = fileReader.nextInt(); fileReader.nextLine();
for (int i = 0; i < num; i++) {
String u = fileReader.nextLine();
String sn = fileReader.nextLine();
String fn = fileReader.nextLine();
String c = fileReader.nextLine();
AddStudent(u, sn, fn, c);
}
fileReader.close();
fileReader = new Scanner(new InputStreamReader(new FileInputStream("modules.txt")));
num = fileReader.nextInt(); fileReader.nextLine();
for (int i = 0; i < num; i++) {
String code = fileReader.nextLine();
int numOfStudents = fileReader.nextInt(); fileReader.nextLine();
String[] students = new String[numOfStudents];
for (int j = 0; j < numOfStudents; j++) {
students[j] = fileReader.nextLine();
}
AddModule(code, students);
}
fileReader.close();
} catch (IOException e) {}
}
public void saveToTextFiles () {
try {
PrintWriter outfile = new PrintWriter(new OutputStreamWriter (new FileOutputStream("students.txt")));
outfile.println(studentList.length);
for (int i = 0; i < studentList.length; i++) {
outfile.println(studentList[i].getUID());
outfile.println(studentList[i].getSN());
outfile.println(studentList[i].getFN());
outfile.println(studentList[i].getDegree());
}
outfile.close();
outfile = new PrintWriter(new OutputStreamWriter (new FileOutputStream("modules.txt")));
outfile.println(moduleList.length);
for (int i = 0; i < moduleList.length; i++) {
outfile.println(moduleList[i].getCode());
outfile.println(moduleList[i].getStudents().length);
for (int j = 0; j < moduleList[i].getStudents().length; j++) {
outfile.println(moduleList[i].getStudents()[j]);
}
}
outfile.close();
} catch (IOException e) {}
}
public void saveSerialized() {
try {
FileOutputStream fileOut = new FileOutputStream("Model.ser");
ObjectOutputStream out = new ObjectOutputStream(fileOut);
out.writeObject(this);
out.close();
fileOut.close();
FileOutputStream fileOut2 = new FileOutputStream("Module.ser");
ObjectOutputStream out2 = new ObjectOutputStream(fileOut2);
out2.writeObject(studentList);
out2.close();
fileOut2.close();
FileOutputStream fileOut3 = new FileOutputStream("Student.ser");
ObjectOutputStream out3 = new ObjectOutputStream(fileOut3);
out3.writeObject(moduleList);
out3.close();
fileOut3.close();
} catch (IOException e) {}
}
public void loadSerialized() {
Model m = null;
try {
FileInputStream fileIn = new FileInputStream("Model.ser");
ObjectInputStream in = new ObjectInputStream(fileIn);
m = (Model) in.readObject();
in.close();
fileIn.close();
} catch (Exception e) {}
setStudentList(m.getStudentList());
setModuleList(m.getModuleList());
}
private Module[] getModuleList() {
return moduleList;
}
private Student[] getStudentList() {
return studentList;
}
private void setModuleList(Module[] m) {
moduleList = m.clone();
}
private void setStudentList(Student[] s) {
studentList = s.clone();
}
private void AddModule(String code, String[] students) {
int length = moduleList.length;
Module NewArray[] = new Module[length + 1];
for (int i = 0; i < length + 1; i++) {
if (i < length) {
NewArray[i] = new Module(moduleList[i]);
}
}
NewArray[length] = new Module(code, students);
moduleList = NewArray.clone();
}
private void AddStudent(String u, String sn, String fn, String c) {
int length = studentList.length;
Student NewArray[] = new Student[length + 1];
for(int i = 0; i < length + 1; i++) {
if (i < length) {
NewArray[i] = new Student(studentList[i]);
}
}
NewArray[length] = new Student(u, sn, fn, c);
studentList = NewArray.clone();
}
public void printReport() {
for (int i = 0; i < moduleList.length; i++) {
System.out.println(moduleList[i].toString(this));
}
}
public Student findAStudent(String uid) {
for (int i = 0; i < studentList.length; i++) {
if (studentList[i].getUID().compareTo(uid) == 0) {
return studentList[i];
}
}
return null;
}
public Module findAModule(String code) {
for (int i = 0; i < moduleList.length; i++) {
if (moduleList[i].getCode().compareTo(code) == 0) {
return moduleList[i];
}
}
return null;
}
}
import java.io.*;
导入java.util.*;
公共类模型实现java.io.Serializable{
私立学生[]学生名单=新学生[0];
私有模块[]模块列表=新模块[0];
公共无效菜单(){
while(true){
System.out.println(“菜单”);
System.out.println(“”);
System.out.println(“1-运行测试”);
System.out.println(“2-添加学生”);
System.out.println(“3-添加模块”);
System.out.println(“4-将学生添加到模块”);
System.out.println(“5-保存系统(文本文件)”;
System.out.println(“6-加载系统(文本文件)”;
System.out.println(“7-保存系统(序列化)”;
System.out.println(“8-加载系统(序列化)”;
System.out.println(“9-打印报告”);
System.out.println(“”);
System.out.print(“输入选项:”);
字符串输入=键盘.readString();
开关(输入){
案例“1”:
运行测试();
打破
案例“2”:
系统输出打印(“名字:”);
String fN=keyboard.readString();
系统输出打印(“姓氏:”);
String sN=键盘。readString();
系统输出打印(“课程代码:”);
String c=keyboard.readString();
系统输出打印(“用户ID:”);
String iD=keyboard.readString();
AddStudent(iD、序号、fN、c);
打破
案例“3”:
系统输出打印(“模块代码:”);
字符串代码=keyboard.readString();
字符串[]临时=新字符串[0];
添加模块(代码、温度);
打破
案例“4”:
系统输出打印(“模块代码:”);
code=keyboard.readString();
模块m=FindModule(代码);
如果(m!=null){
系统输出打印(“用户ID:”);
iD=keyboard.readString();
学生s=FindAstuent(iD);
如果(s!=null){
m、 添加该学生;
}否则{
System.out.println(“未找到学生”);
}
}否则{
System.out.println(“未找到模块”);
}
打破
案例“5”:
saveToTextFiles();
打破
案例“6”:
loadFromTextFiles();
打破
案例“7”:
saveSerialized();
打破
案例“8”:
打破
案例“9”:
打印报告();
打破
}
}
}
公共无效运行测试(){
loadFromTextFiles();
saveSerialized();
打印报告();
}
公共void loadFromTextFiles(){
studentList=新学生[0];
moduleList=新模块[0];
试一试{
Scanner fileReader=new Scanner(new InputStreamReader(new FileInputStream(“students.txt”));
int num=fileReader.nextInt();fileReader.nextLine();
for(int i=0;iswitch (input) {
...
case "8" :
break;
...
}