JAVA-使用套接字和线程接收对象不工作

我正在尝试从服务器获取对象，但它不起作用

服务器的相关部分（通过调试，我发现他确实发送了正确的对象）：

根据我在这里读到的答案，我尝试将线程分为两个（一个输入，另一个输出在服务器和客户机中），但没有帮助。 他还试图改变输入和输出的顺序，但没有成功

• 没有错误
• 客户端无法获取对象

这里有什么问题

编辑。学生班级：

public class Student implements  Externalizable
{ 
    private final SimpleIntegerProperty ID;
    private final SimpleStringProperty firstName;
    private final SimpleStringProperty lastName;
    private final SimpleStringProperty address;
    private final SimpleObjectProperty<Date> birthDate;
    private final SimpleStringProperty department;
    private final SimpleIntegerProperty pointsAmount;
    private final SimpleObjectProperty<Date> startStudyingDate;
    private final SimpleIntegerProperty failedAmount;
    private final SimpleDoubleProperty average;
    private final SimpleIntegerProperty lavelByGrade;
    private final SimpleStringProperty pic;

    public Student(int ID, String firstName, String lastName, String address,
            Date  birthDate, String department,
            int pointsAmount, Date startStudyingDate, int failedAmount, 
            double average, int  lavelByGrade, String pic){

        this.ID= new SimpleIntegerProperty(ID);
        this.firstName= new SimpleStringProperty(firstName);
        this.lastName= new SimpleStringProperty(lastName);
        this.address= new SimpleStringProperty(address);
        this.birthDate= new SimpleObjectProperty<Date>(birthDate);
        this.department= new SimpleStringProperty(department);
        this.pointsAmount= new SimpleIntegerProperty(pointsAmount);
        this.startStudyingDate= new  SimpleObjectProperty<Date>(startStudyingDate);
        this.failedAmount= new SimpleIntegerProperty(failedAmount);
        this.average= new SimpleDoubleProperty(average);
        this.lavelByGrade= new SimpleIntegerProperty(lavelByGrade);
        this.pic = new SimpleStringProperty(pic);
    }

    public int getID() {
        return ID.get();
    }
    public void setID(int ID) {
        this.ID.set(ID);
    }

    public String getFirstName() {
        return firstName.get();
    }

    public void setFirstName(String firstName) {
        this.firstName.set(firstName);
    }

    public String getLastName() {
        return lastName.get();
    }

    public void setLastName(String lastName) {
        this.lastName.set(lastName);
    }

    public String getAddress() {
        return address.get();
    }

    public void setAddress(String address) {
        this.address.set(address);
    }

    public Date getBirthDate() {
        return birthDate.get();
    }

    public void setBirthDate(Date birthDate) {
        this.birthDate.set(birthDate);
    }

    public String getDepartment() {
        return department.get();
    }

    public void setDepartment(String department) {
        this.department.set(department);
    }

    public int getPointsAmount() {
        return pointsAmount.get();
    }

    public void setPointsAmount(int pointsAmount) {
        this.pointsAmount.set(pointsAmount);
    }

    public Date getStartStudyingDate() {
        return startStudyingDate.get();
    }

    public void setStartStudyingDate(Date startStudyingDate) {
        this.startStudyingDate.set(startStudyingDate);
    }

    public int getFailedAmount() {
        return failedAmount.get();
    }

    public void setFailedAmount(int failedAmount) {
        this.failedAmount.set(failedAmount);
    }

    public double getAverage() {
        return average.get();
    }

    public void setAverage(Double average) {
        this.average.set(average);
    }

    public int getLavelByGrade() {
        return lavelByGrade.get();
    }

    public void setLavelByGrade(int lavelByGrade) {
        this.lavelByGrade.set(lavelByGrade);
    }

    public String getPic() {
        return pic.get();
    }

    public void setPic(String pic) {
        this.pic.set(pic);
    }

    @Override
    public void readExternal(ObjectInput in) throws IOException,
            ClassNotFoundException {

        setID(in.readInt());
        setFirstName((String)in.readObject());
        setLastName((String)in.readObject());
        setAddress((String)in.readObject());
        setBirthDate((Date)in.readObject());
        setDepartment((String)in.readObject());
        setPointsAmount(in.readInt());
        setStartStudyingDate((Date)in.readObject());
        setFailedAmount(in.readInt());
        setAverage(in.readDouble());
        setLavelByGrade(in.readInt());
        setPic((String)in.readObject());
    }

    @Override
    public void writeExternal(ObjectOutput out) throws IOException {

        out.writeInt(getID());
        out.writeObject(getFirstName()); 
        out.writeObject(getLastName()); 
        out.writeObject(getAddress()); 
        out.writeObject(getBirthDate());
        out.writeObject(getDepartment());
        out.writeInt(getPointsAmount()); 
        out.writeObject(getStartStudyingDate()); 
        out.writeInt(getFailedAmount()); 
        out.writeDouble(getAverage()); 
        out.writeInt(getLavelByGrade());
        out.writeObject(getPic()); 

    }
}   

公共类学生实现可外部化
{ 
私有最终SimpleIntegerProperty ID；
私有最终SimpleStringProperty名字；
私有最终SimpleStringProperty姓氏；
私人最终SimpleStringProperty地址；
私有最终SimpleObject属性生日；
私人物业署；
私有最终SimpleIntegerProperty pointsAmount；
私有最终SimpleObject属性开始学习日期；
私有最终SimpleIntegerProperty失败装载；
私人最终简化不动产平均值；
lavelByGrade私有最终简单集成财产；
私人最终财产；
公立学生（int-ID、String-firstName、String-lastName、String-address、，
日期出生日期弦乐部，
int pointsAmount，Date STARTSTUDINGDATE，int failedAmount，
双倍平均值，整数lavelByGrade，字符串pic）{
this.ID=新的SimpleIntegerProperty（ID）；
this.firstName=新的SimpleStringProperty（firstName）；
this.lastName=新的SimpleStringProperty（lastName）；
this.address=新的SimpleStringProperty（地址）；
this.birthDate=新的SimpleObject属性（birthDate）；
this.department=新SimpleStringProperty（department）；
this.pointsAmount=新的SimpleIntegerProperty（pointsAmount）；
this.startstudingDate=新的SimpleObject属性（startstudingDate）；
this.failedAmount=新的SimpleIntegerProperty（failedAmount）；
this.average=新的SimpleDoubleProperty（平均值）；
this.lavelByGrade=新的SimpleIntegerProperty（lavelByGrade）；
this.pic=新的SimpleStringProperty（pic）；
}
公共int getID（）{
返回ID.get（）；
}
公共无效集合ID（内部ID）{
此.ID.set（ID）；
}
公共字符串getFirstName（）{
返回firstName.get（）；
}
public void setFirstName（字符串firstName）{
this.firstName.set（firstName）；
}
公共字符串getLastName（）{
返回lastName.get（）；
}
public void setLastName（字符串lastName）{
this.lastName.set（lastName）；
}
公共字符串getAddress（）{
返回地址。get（）；
}
公共无效设置地址（字符串地址）{
this.address.set（地址）；
}
公共日期getBirthDate（）{
返回生日。get（）；
}
公共无效设置出生日期（日期出生日期）{
this.birthDate.set（birthDate）；
}
公共部门（）{
返回部门。get（）；
}
公共部门（字符串部门）{
本.department.set（department）；
}
public int getPointsAmount（）{
返回点samount.get（）；
}
公共无效setPointsAmount（int pointsAmount）{
this.pointsAmount.set（pointsAmount）；
}
公共日期getStartStudyingDate（）{
return startstudingDate.get（）；
}
公共无效设置开始学习日期（开始学习日期）{
this.startstudingDate.set（startstudingDate）；
}
public int getFailedAmount（）{
返回failedAmount.get（）；
}
公共void setFailedAmount（int failedAmount）{
this.failedAmount.set（failedAmount）；
}
公共双平均值（）{
返回average.get（）；
}
公众平均（双倍平均）{
此.average.set（平均值）；
}
公共int getLavelByGrade（）{
返回lavelByGrade.get（）；
}
公共无效setLavelByGrade（int lavelByGrade）{
this.lavelByGrade.set（lavelByGrade）；
}
公共字符串getPic（）{
返回pic.get（）；
}
公共void setPic（字符串pic）{
此.pic.set（pic）；
}
@凌驾
public void readExternal（ObjectInput in）引发IOException，
ClassNotFoundException{
setID（in.readInt（））；
setFirstName（.readObject（）中的字符串）；
setLastName（.readObject（）中的字符串）；
setAddress（.readObject（）中的字符串）；
setBirthDate（.readObject（）中的（日期））；
setDepartment（.readObject（）中的字符串）；
setPointsAmount（in.readInt（））；
setStartStudyingDate（.readObject（）中的（日期））；
setFailedAmount（in.readInt（））；
setAverage（in.readDouble（））；
setLavelByGrade（in.readInt（））；
setPic（.readObject（）中的（字符串）；
}
@凌驾
public void writeExternal（ObjectOutput out）引发IOException{
out.writeInt（getID（））；
writeObject（getFirstName（））；
writeObject（getLastName（））；
writeObject（getAddress（））；
writeObject（getBirthDate（））；
out.writeObject（getDepartment（））；
writeInt（getPointsAmount（））；
writeObject（getStartStudyingDate（））；
out.writeInt（getFailedAmount（））；
out.writeDouble（getAverage（））；
out.writeInt（getLavelByGrade（））；
writeObject（getPic（））；
}
}   

试试这篇文章，用下面的文本搜索部分，并且可以外部化：很长一段时间以来，我认为JavaFX属性缺乏对序列化的支持，这确实阻止了它们在任何服务器端容量中使用

---

JavaFX属性不可序列化。因此，如果您尝试序列化一个使用JavaFX属性作为其状态的对象，您将得到一个异常

你有几个选择。一种是不使用Java对象序列化，而是使用其他一些序列化技术，例如

    private void connectToServer(){
    try{
        // Create a socket to connect to the server
        socket = new Socket(host, 8000);
        // Create an input stream to receive Object from the server
        fromServer = new ObjectInputStream(socket.getInputStream());
        // Create an output stream to send data to the server
        toServer = new DataOutputStream(socket.getOutputStream());

    }
    catch (Exception ex){
        ex.printStackTrace();
    }
}

private void sendAndGetFromServer(String sqlQuery){
    new Thread(() ->{
        try{

            System.out.println("a1");
            // Send sql query to server
            toServer.writeUTF(sqlQuery);
            //toServer.flush();
            // Get notification from the server

            Student[] rows = (Student[])fromServer.readObject();
            setRowsInTable(rows);
        }
        catch(SocketException ex){
            try{
                socket.close();
            } 
            catch (IOException e){ 
            }
        } 
        catch (Exception ex){
        }
    }).start();

public class Student implements  Externalizable
{ 
    private final SimpleIntegerProperty ID;
    private final SimpleStringProperty firstName;
    private final SimpleStringProperty lastName;
    private final SimpleStringProperty address;
    private final SimpleObjectProperty<Date> birthDate;
    private final SimpleStringProperty department;
    private final SimpleIntegerProperty pointsAmount;
    private final SimpleObjectProperty<Date> startStudyingDate;
    private final SimpleIntegerProperty failedAmount;
    private final SimpleDoubleProperty average;
    private final SimpleIntegerProperty lavelByGrade;
    private final SimpleStringProperty pic;

    public Student(int ID, String firstName, String lastName, String address,
            Date  birthDate, String department,
            int pointsAmount, Date startStudyingDate, int failedAmount, 
            double average, int  lavelByGrade, String pic){

        this.ID= new SimpleIntegerProperty(ID);
        this.firstName= new SimpleStringProperty(firstName);
        this.lastName= new SimpleStringProperty(lastName);
        this.address= new SimpleStringProperty(address);
        this.birthDate= new SimpleObjectProperty<Date>(birthDate);
        this.department= new SimpleStringProperty(department);
        this.pointsAmount= new SimpleIntegerProperty(pointsAmount);
        this.startStudyingDate= new  SimpleObjectProperty<Date>(startStudyingDate);
        this.failedAmount= new SimpleIntegerProperty(failedAmount);
        this.average= new SimpleDoubleProperty(average);
        this.lavelByGrade= new SimpleIntegerProperty(lavelByGrade);
        this.pic = new SimpleStringProperty(pic);
    }

    public int getID() {
        return ID.get();
    }
    public void setID(int ID) {
        this.ID.set(ID);
    }

    public String getFirstName() {
        return firstName.get();
    }

    public void setFirstName(String firstName) {
        this.firstName.set(firstName);
    }

    public String getLastName() {
        return lastName.get();
    }

    public void setLastName(String lastName) {
        this.lastName.set(lastName);
    }

    public String getAddress() {
        return address.get();
    }

    public void setAddress(String address) {
        this.address.set(address);
    }

    public Date getBirthDate() {
        return birthDate.get();
    }

    public void setBirthDate(Date birthDate) {
        this.birthDate.set(birthDate);
    }

    public String getDepartment() {
        return department.get();
    }

    public void setDepartment(String department) {
        this.department.set(department);
    }

    public int getPointsAmount() {
        return pointsAmount.get();
    }

    public void setPointsAmount(int pointsAmount) {
        this.pointsAmount.set(pointsAmount);
    }

    public Date getStartStudyingDate() {
        return startStudyingDate.get();
    }

    public void setStartStudyingDate(Date startStudyingDate) {
        this.startStudyingDate.set(startStudyingDate);
    }

    public int getFailedAmount() {
        return failedAmount.get();
    }

    public void setFailedAmount(int failedAmount) {
        this.failedAmount.set(failedAmount);
    }

    public double getAverage() {
        return average.get();
    }

    public void setAverage(Double average) {
        this.average.set(average);
    }

    public int getLavelByGrade() {
        return lavelByGrade.get();
    }

    public void setLavelByGrade(int lavelByGrade) {
        this.lavelByGrade.set(lavelByGrade);
    }

    public String getPic() {
        return pic.get();
    }

    public void setPic(String pic) {
        this.pic.set(pic);
    }

    @Override
    public void readExternal(ObjectInput in) throws IOException,
            ClassNotFoundException {

        setID(in.readInt());
        setFirstName((String)in.readObject());
        setLastName((String)in.readObject());
        setAddress((String)in.readObject());
        setBirthDate((Date)in.readObject());
        setDepartment((String)in.readObject());
        setPointsAmount(in.readInt());
        setStartStudyingDate((Date)in.readObject());
        setFailedAmount(in.readInt());
        setAverage(in.readDouble());
        setLavelByGrade(in.readInt());
        setPic((String)in.readObject());
    }

    @Override
    public void writeExternal(ObjectOutput out) throws IOException {

        out.writeInt(getID());
        out.writeObject(getFirstName()); 
        out.writeObject(getLastName()); 
        out.writeObject(getAddress()); 
        out.writeObject(getBirthDate());
        out.writeObject(getDepartment());
        out.writeInt(getPointsAmount()); 
        out.writeObject(getStartStudyingDate()); 
        out.writeInt(getFailedAmount()); 
        out.writeDouble(getAverage()); 
        out.writeInt(getLavelByGrade());
        out.writeObject(getPic()); 

    }
}   

import java.io.Externalizable ;
import java.io.IOException ;
import java.io.ObjectInput ;
import java.io.ObjectOutput ;

import javafx.beans.property.IntegerProperty ;
import javafx.beans.property.SimpleIntegerProperty ;
import javafx.beans.property.SimpleStringProperty ;
import javafx.beans.property.StringProperty ;

public class Person implements Externalizable {

    private final StringProperty name = new SimpleStringProperty();
    private final IntegerProperty id = new SimpleIntegerProperty();

    public StringProperty nameProperty() {
        return name ;
    }
    public final String getName() {
        return nameProperty().get();
    }
    public final void setName(String name) {
        nameProperty().set(name);
    }

    public IntegerProperty idProperty() {
        return id ;
    }
    public final int getId() {
        return idProperty().get();
    }
    public final void setId(int id) {
        idProperty().set(id);
    }

    // important: must have a no-arg constructor:
    public Person() { }

    public Person(int id, String name) {
        setId(id);
        setName(name);
    }

    @Override
    public void writeExternal(ObjectOutput out) throws IOException {
        // write id then name
        // note we write the contents of the properties, not the properties 
        // themselves, as the properties are not serializable:
        out.writeInt(getId());
        out.writeObject(getName());
    }

    @Override
    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        // read data back in same order:
        setId(in.readInt());
        setName((String)in.readObject());
    }
}

ObjectOutputStream oos = ... ;
oos.writeObject(new Person(007, "James Bond"));