我正在做一个作业，我必须以序列化模式来回发送一个对象。我有一个 Client3.java 文件，它将一个对象发送到 Server3.java。而 Server3.java 做同样的事情。但是当我尝试读取 Client3 中的对象，他抛出了一个java.io.IOException: Premature EOF错误。通过广泛的搜索，我发现我的程序运行速度比 InputStream 读取速度快，但我不知道如何解决这个问题
这是我的 2 个文件
package server3;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.net.HttpURLConnection;
import java.net.URL;
public class Client3 {
public static void main(String[] args) throws Exception {
try {
URL url = new URL("http://localhost:3333");
HttpURLConnection s = (HttpURLConnection) url.openConnection();
s.setDoOutput(true);
s.setDoInput(true);
s.setRequestMethod("POST");
s.setUseCaches(false);
//here we send an serialized object
Send obj = new Send();
ObjectOutputStream objOut = new
ObjectOutputStream(s.getOutputStream());
objOut.writeObject(obj);
/*********this is the chunk of code that makes the error*****************/
//here we read the serialized object
InputStream in = s.getInputStream();
ObjectInputStream ios = new ObjectInputStream(in);
SendResponse oin = (SendResponse) ios.readObject();
String gabim=oin.getGabim();
String gabimNr =oin.getGabimNr();
System.out.println(gabim);
System.out.println(gabimNr);
ios.close();
s.disconnect();
/***************************************************************************/
//catch all the possible errors
} catch (IOException ex) {
System.err.println("Gabim ne klient"+ex);
ex.printStackTrace();
}
}
}
class Send implements Serializable {
// the object to be send to the server
private static final long serialVersionUID = 1L;
int id = 1;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public int getAmount() {
return amount;
}
public void setAmount(int amount) {
this.amount = amount;
}
public int getPaid() {
return paid;
}
public void setPaid(int paid) {
this.paid = paid;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
int amount = 2000;
int paid = 800;
String name = "Andi Domi";
}
这里是 Server3.java 文件
package server3;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.net.InetSocketAddress;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;
public class Server3 {
public static void main(String[] args) throws Exception {
//create the server
HttpServer server = HttpServer.create(new InetSocketAddress(3333), 0);
server.createContext("/", new MyHandler());
server.setExecutor(null); // creates a default executor
server.start();
}
static class MyHandler implements HttpHandler {
public void handle(HttpExchange t) throws IOException {
/*******we start to read the object send from the client here*******/
//create the sream
ObjectInputStream ios = new ObjectInputStream(t.getRequestBody());
//variables we need to connect to the database
final String url = "jdbc:mysql://localhost/httpServer";
final String user = "root";
final String password = "";
try {
//create the object to be read
Send oin = (Send) ios.readObject();
int id = oin.getId();
String emri = oin.getName();
int amount = oin.getAmount();
int paid = oin.getPaid();
//jdbc try
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection(url, user,password);
//insert values into the first table
PreparedStatement s = con
.prepareStatement("INSERT INTO person(ID,Name,Amount,Paid) VALUES (?,?,?,?)");
s.setInt(1, id);
s.setString(2, emri);
s.setInt(3, amount);
s.setInt(4, paid);
s.executeUpdate();
//read the values from a table and add them to an array list
ResultSet rs = s.executeQuery("SELECT * from personat ORDER BY ID");
ArrayList<Personat> perList = new ArrayList<Personat>();
if (rs != null) {
while (rs.next()) {
Personat per = new Personat();
per.setID(rs.getInt("ID"));
per.setName(rs.getString("Name"));
per.setAmount(rs.getInt("Amount"));
perList.add(per);
}
}
//send the serialized object
String gabim="Ska asnje gabim";
String gabimNr="1";
t.sendResponseHeaders(200,0);
OutputStream os = t.getResponseBody();
SendResponse obj = new SendResponse(gabim,gabimNr,perList);
ObjectOutputStream objOut = new ObjectOutputStream(os);
objOut.writeObject(obj);
objOut.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
//ketu cojme nje object me keto te dhena
String gabim=("Dicka nuk shkoi mire me marrjen e objektit");
String gabimNr="3";
rrayList<Personat> perList = null;
t.sendResponseHeaders(200,0);
OutputStream os = t.getResponseBody();
SendResponse obj = new SendResponse(gabim,gabimNr,perList);
ObjectOutputStream objOut = new ObjectOutputStream(os);
objOut.writeObject(obj);
objOut.close();
} catch (SQLException e) {
//ketu cojme nje objekt me keto te dhena
e.printStackTrace();
String gabim=("Dicka nuk shkoi mire ne lidhje me databasin");
String gabimNr="4";
ArrayList<Personat> perList = null;
t.sendResponseHeaders(200,0);
OutputStream os = t.getResponseBody();
SendResponse obj = new SendResponse(gabim,gabimNr,perList);
ObjectOutputStream objOut = new ObjectOutputStream(os);
objOut.writeObject(obj);
objOut.close();
}
}
}
}
class Personat {
int ID;
String Name;
int Amount;
public int getID() {
return ID;
}
public void setID(int iD) {
ID = iD;
}
public String getName() {
return Name;
}
public void setName(String name) {
Name = name;
}
public int getAmount() {
return Amount;
}
public void setAmount(int amount) {
Amount = amount;
}
}
class SendResponse implements Serializable {
private static final long serialVersionUID = 1L;
String gabim;
String gabimNr;
ArrayList<Personat> personList;
public SendResponse(String gabim, String gabimNr,
ArrayList<Personat> personList) {
super();
this.gabim = gabim;
this.gabimNr = gabimNr;
this.personList = personList;
}
public String getGabim() {
return gabim;
}
public void setGabim(String gabim) {
this.gabim = gabim;
}
public String getGabimNr() {
return gabimNr;
}
public void setGabimNr(String gabimNr) {
this.gabimNr = gabimNr;
}
public ArrayList<Personat> getPersonList() {
return personList;
}
public void setPersonList(ArrayList<Personat> personList) {
this.personList = personList;
}
}
ex.printStackTrace();在我从Client3 文件中运行它之后，我得到了这个：
java.io.IOException: Premature EOF
java.io.IOException: Premature EOF
at sun.net.www.http.ChunkedInputStream.readAheadBlocking(Unknown Source)
at sun.net.www.http.ChunkedInputStream.readAhead(Unknown Source)
at sun.net.www.http.ChunkedInputStream.read(Unknown Source)
at java.io.FilterInputStream.read(Unknown Source)
at sun.net.www.protocol.http.HttpURLConnection$HttpInputStream.read(Unknown Source)
at java.io.ObjectInputStream$PeekInputStream.read(Unknown Source)
at java.io.ObjectInputStream$PeekInputStream.readFully(Unknown Source)
at java.io.ObjectInputStream$BlockDataInputStream.readShort(Unknown Source)
at java.io.ObjectInputStream.readStreamHeader(Unknown Source)
at java.io.ObjectInputStream.<init>(Unknown Source)
at server3.Client3.main(Client3.java:29)
我不知道如何更快地读取文件或让我的程序变慢，有人知道吗？