我正在使用Java制作网络程序。作为标题，服务器尝试发送的对象在接收它的客户端中更改。在我从服务器收到新对象之前，我试图更改客户端中存在的对象。 这是我的代码。第一个是Server.sendIdea，第二个是Client.rcvIdea。
void sendIdea(Idea _idea) throws IOException {
objectOS.flush();
Idea idea = _idea;
//when I look into 'idea' it's fine
objectOS.writeObject(idea);
}
...
Idea rcvIdea(int _ideaCode) throws ClassNotFoundException, IOException {
objectOS.writeObject("sendIdea");
objectOS.writeObject(_ideaCode);
Idea returnValue = (Idea) objectIS.readObject();
//when I look into 'returnValue', it is not the one 'sendIdea' has sent.
return returnValue;
}
如您所见，sendIdea(Idea _idea)正在使用Idea方法从班级writeObject发送对象。并且rcvIdea()正在使用readObject()方法接收对象。 （我确定你不必详细了解课程Idea）。通过这种方法，客户端在该程序开始时实际上收到了一些Idea，并且没有问题。但是当我尝试通过此方法接收相同但略微更改的对象Idea时，在Client类中对象不会更改，而不像Server类中的对象将要更改由sendIdea方法发送的方法已正确更改。我尝试了大约5个小时来解决这个问题。我逐行检查了所有代码，一无所获。我很确定writeObject或readObject方法有问题。我试过objectOS.flush()以清除流和许多其他试验。我希望我能找到问题。以下是我的程序中的一些代码
Client.class 包装想法海洋;
import java.awt.HeadlessException;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.ArrayList;
import javax.swing.JOptionPane;
import data.Idea;
import data.Opinion;
import data.Profile;
public class Client {
Socket socket;
OutputStream os;
ObjectOutputStream objectOS;
InputStream is;
ObjectInputStream objectIS;
MainWindow mainWindow;
int idCode;
String email, password;
Profile myProfile;
ArrayList<Idea> myIdeas;
ArrayList<Opinion> myOpinions;
ArrayList<Integer> newIdeasCodes, hotIdeasCodes;
ArrayList<Idea> newIdeas, hotIdeas;
String command;
static final String SERVER_IP = "127.0.0.1";//
static final int SERVER_PORT_NUM = 5000;
public static void main(String[] args) {
Client client = new Client();
client.mainWindow = new MainWindow();
client.mainWindow.setVisible(true);
client.mainWindow.showLoginPg();
try {
while (!client.loginCheck()) {// login
continue;
}
} catch (HeadlessException | NumberFormatException | ClassNotFoundException | IOException e) {
e.printStackTrace();
}
System.out.println("[login complete]");
try {
client.myProfile = client.rcvProfile(client.idCode);// get myProfile
int i;
for (i = 0; i < client.myProfile.myIdeaCode.size(); i++) {
client.myIdeas.add(client.rcvIdea(client.myProfile.myIdeaCode.get(i)));
}
for (i = 0; i < client.myProfile.myOpinionCode.size(); i++) {
client.myOpinions.add(client.rcvOpinion(client.myProfile.myOpinionCode.get(i)));
}
// ***************************
} catch (ClassNotFoundException | IOException e1) {
e1.printStackTrace();
}
try {
client.rcvNewIdeas(12);
client.mainWindow.newOcean.floatingIdeas = client.newIdeas;
client.mainWindow.newOcean.arrangeFloatingPanels();
client.rcvHotIdeas(12);
client.mainWindow.hotOcean.floatingIdeas = client.hotIdeas;
client.mainWindow.hotOcean.arrangeFloatingPanels();
} catch (ClassNotFoundException | IOException e) {
e.printStackTrace();
}
client.mainWindow.setMyPg(client.myProfile, client.myIdeas, client.myOpinions);
client.mainWindow.showMainPg();
client.start();
}
public Client() {
try {
socket = new Socket(SERVER_IP, SERVER_PORT_NUM);
System.out.println("Connected to Server!");
os = socket.getOutputStream();
objectOS = new ObjectOutputStream(os);
is = socket.getInputStream();
objectIS = new ObjectInputStream(is);
myIdeas = new ArrayList<>();
myOpinions = new ArrayList<>();
newIdeasCodes = new ArrayList<>();
hotIdeasCodes = new ArrayList<>();
newIdeas = new ArrayList<>();
hotIdeas = new ArrayList<>();
} catch (UnknownHostException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
void start() {
while (true) {
try {
if (mainWindow.newBtnClicked) {
rcvNewIdeas(12);
mainWindow.newOcean.floatingIdeas = newIdeas;
mainWindow.newOcean.arrangeFloatingPanels();
mainWindow.newBtnClicked = false;
} else if (mainWindow.hotBtnClicked) {
rcvHotIdeas(12);
mainWindow.hotOcean.floatingIdeas = hotIdeas;
mainWindow.hotOcean.arrangeFloatingPanels();
mainWindow.hotBtnClicked = false;
} else if (mainWindow.newOcean.detailBtnClicked) {
updateIdeaDetailFrame(mainWindow.newOcean.clickedIdea);
mainWindow.newOcean.detailBtnClicked = false;
} else if (mainWindow.hotOcean.detailBtnClicked) {
updateIdeaDetailFrame(mainWindow.hotOcean.clickedIdea);
mainWindow.hotOcean.detailBtnClicked = false;
} else if (mainWindow.ideaDetailFrame.saveOpinionBtnClicked) {
sendOpinion(mainWindow.ideaDetailFrame.newOpinion);
updateIdeaDetailMainPanel(rcvIdea(mainWindow.ideaDetailFrame.idea.ideaCode));
mainWindow.ideaDetailFrame.saveOpinionBtnClicked = false;
} else if (mainWindow.writeIdeaPg.postIdeaBtnClicked) {
sendIdea(mainWindow.writeIdeaPg.thisIdea);
mainWindow.writeIdeaPg.postIdeaBtnClicked = false;
} else if (mainWindow.newOcean.plusBtnClicked) {
objectOS.writeObject("plusBtnClicked");
objectOS.writeObject(mainWindow.newOcean.plusMinusClickedIdeaCode);
mainWindow.newOcean.plusBtnClicked = false;
} else if (mainWindow.newOcean.minusBtnClicked) {
objectOS.writeObject("minusBtnClicked");
objectOS.writeObject(mainWindow.newOcean.plusMinusClickedIdeaCode);
mainWindow.newOcean.minusBtnClicked = false;
} else if (mainWindow.hotOcean.plusBtnClicked) {
objectOS.writeObject("plusBtnClicked");
objectOS.writeObject(mainWindow.hotOcean.plusMinusClickedIdeaCode);
mainWindow.hotOcean.plusBtnClicked = false;
} else if (mainWindow.hotOcean.minusBtnClicked) {
objectOS.writeObject("minusBtnClicked");
objectOS.writeObject(mainWindow.hotOcean.plusMinusClickedIdeaCode);
mainWindow.hotOcean.minusBtnClicked = false;
} else if (mainWindow.myBtnClicked) {
mainWindow.setMyPg(myProfile, myIdeas, myOpinions);
mainWindow.myBtnClicked = false;
}
} catch (ClassNotFoundException | IOException e) {
e.printStackTrace();
}
}
}
int i = 0;
Idea rcvIdea(int _ideaCode) throws ClassNotFoundException, IOException {
objectOS.writeObject("sendIdea");
objectOS.writeObject(_ideaCode);
Idea returnValue = (Idea) objectIS.readObject();
return returnValue;
}
Opinion rcvOpinion(int _opinionCode) throws ClassNotFoundException, IOException {
objectOS.writeObject("sendOpinion");
objectOS.writeObject(_opinionCode);
return (Opinion) objectIS.readObject();
}
Profile rcvProfile(int _idCode) throws IOException, ClassNotFoundException {
objectOS.writeObject("sendProfile");
objectOS.writeObject(_idCode);
return (Profile) objectIS.readObject();
}
void rcvNewIdeasCodes() throws ClassNotFoundException, IOException {
objectOS.writeObject("sendNewIdeasCodes");
newIdeasCodes = (ArrayList<Integer>) objectIS.readObject();
}
void rcvHotIdeasCodes() throws IOException, ClassNotFoundException {
objectOS.writeObject("sendHotIdeasCodes");
hotIdeasCodes = (ArrayList<Integer>) objectIS.readObject();
}
void rcvNewIdeas(int num) throws ClassNotFoundException, IOException {
int i;
rcvNewIdeasCodes();
newIdeas = new ArrayList<>();
if (num <= newIdeasCodes.size()) {
for (i = 0; i < num; i++) {
newIdeas.add(rcvIdea(newIdeasCodes.get(i)));
}
} else {
for (i = 0; i < newIdeasCodes.size(); i++) {
newIdeas.add(rcvIdea(newIdeasCodes.get(i)));
}
}
}
void rcvHotIdeas(int num) throws ClassNotFoundException, IOException {
int i;
rcvHotIdeasCodes();
hotIdeas = new ArrayList<>();
if (num <= hotIdeasCodes.size()) {
for (i = 0; i < num; i++) {
hotIdeas.add(rcvIdea(hotIdeasCodes.get(i)));
}
} else {
for (i = 0; i < hotIdeasCodes.size(); i++) {
hotIdeas.add(rcvIdea(hotIdeasCodes.get(i)));
}
}
}
void sendIdea(Idea _idea) throws IOException {
objectOS.writeObject("rcvIdea");
objectOS.writeObject(_idea);
}
void sendOpinion(Opinion _opinion) throws IOException {
objectOS.writeObject("rcvOpinion");
objectOS.writeObject(_opinion);
}
void sendProfile(Profile _profile) throws IOException {
objectOS.writeObject(_profile);
}
boolean loginCheck() throws HeadlessException, NumberFormatException, IOException, ClassNotFoundException {
objectOS.writeObject("loginCheck");// send command
while (!mainWindow.loginBtnClicked) {
continue;
}
mainWindow.loginBtnClicked = false;
email = mainWindow.emailField.getText().trim();
password = mainWindow.passwordField.getText().trim();
objectOS.writeObject(email);
objectOS.writeObject(password);
boolean valid;
valid = (boolean) objectIS.readObject();
if (valid == false) {
JOptionPane.showMessageDialog(mainWindow, "ID or Password is not correct");
mainWindow.emailField.setText("");
mainWindow.passwordField.setText("");
return false;
} else if (valid == true) {
idCode = (int) objectIS.readObject();
return true;
} else {
return false;
}
}
void updateIdeaDetailMainPanel(Idea clickedIdea) throws ClassNotFoundException, IOException {
ArrayList<Opinion> opinions = new ArrayList<>();
for (int j = 0; j < clickedIdea.opinionCode.size(); j++) {
opinions.add(rcvOpinion(clickedIdea.opinionCode.get(j)));
}
mainWindow.ideaDetailFrame.updateMainPanel(opinions);
}
void updateIdeaDetailFrame(Idea clickedIdea) throws ClassNotFoundException, IOException {
ArrayList<Opinion> opinions = new ArrayList<>();
for (int j = 0; j < clickedIdea.opinionCode.size(); j++) {
opinions.add(rcvOpinion(clickedIdea.opinionCode.get(j)));
}
mainWindow.ideaDetailFrame = new IdeaDetailFrame(clickedIdea, opinions);
mainWindow.ideaDetailFrame.setVisible(true);
}
}
Idea.class 包数据;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
public class Idea implements Serializable {
private static final long serialVersionUID = 123123L;
public int idCode;
public int ideaCode;
public int plus = 0, minus = 0;
public String ideaName;
public String oneLineExp;
public String explanation;
public ArrayList<Integer> opinionCode;
public Date date;
public MyCanvas image;
int hotDegree;
public Idea(int _idCode,int _ideaCode, String _ideaName, String _oneLineExp, String _explanation, MyCanvas _image) {
this(_idCode,_ideaName,_oneLineExp,_explanation,_image);
ideaCode = _ideaCode;
}
public Idea(int _idCode, String _ideaName, String _oneLineExp, String _explanation, MyCanvas _image) {
this(_idCode,_ideaName,_oneLineExp,_explanation);
image = _image;
}
public Idea(int _idCode, String _ideaName, String _oneLineExp, String _explanation){
idCode = _idCode;
oneLineExp = new String(_oneLineExp);
ideaName = new String(_ideaName);
explanation = new String(_explanation);
date = new Date();
opinionCode = new ArrayList<>();
}
public void saveIdea() {
FileOutputStream fos = null;
ObjectOutputStream oos = null;
try {
fos = new FileOutputStream("Idea.dat");
oos = new ObjectOutputStream(fos);
oos.writeObject(this);
} catch (IOException e1) {
System.out.println("e1");
}
}
void addOpinionCode(int _opinion) {
opinionCode.add(opinionCode.size(), _opinion);
}
public void incPlus() {
plus++;
}
public void incMinus() {
minus++;
}
public int setHotDegree() {
hotDegree = plus - minus + opinionCode.size() * 2;
return hotDegree;
}
}
Opinion.class
package data;
import java.io.Serializable;
import java.util.Date;
public class Opinion implements Serializable{
int idCode;
public int opinionCode;//the intrinsic code of this opinion
public int commentedIdeaCode;
public String opinion;
public Date date;
int plus, minus;
public Opinion(int _idCode,int _commentedIdeaCode, String _opinion){
idCode = _idCode;
commentedIdeaCode = _commentedIdeaCode;
opinion = new String(_opinion);
date = new Date();
plus = 0;
minus = 0;
}// Opinion(int _idCode,int _commentedIdeaCode, String _opinion)
public Opinion(int _idCode,int _opinionCode,int _commentedIdeaCode, String _opinion){
this(_idCode, _commentedIdeaCode, _opinion);
opinionCode = _opinionCode;
}//Opinion(int _idCode,int _opinionCode,int _commentedIdeaCode, String _opinion)
void incPlus(){
plus++;
}
void incMinus(){
minus++;
}
}
答案 0 :(得分：1)
ObjectOutputStream创建已经序列化的所有对象的图形，并使用对先前序列化对象的引用。因此，当您多次序列化Idea实例时，每次在第一个实例之后，将写入对第一个序列化的引用而不是完整对象。
每次序列化后都可以使用ObjectOutputStream.reset()。这将丢弃对象图并强制ObjectOutputStream创建新的对象序列化，即使对于之前看到的对象也是如此。
因此，您的sendIdea方法应如下所示：
void sendIdea(Idea _idea) throws IOException {
objectOS.flush();
objectOS.reset();
Idea idea = _idea;
objectOS.writeObject(idea);
}
非常重要的是，请注意在reset（）之后，所有对象引用都会重新序列化。因此，如果您有一个复杂的对象图，则在反序列化后最终可能会出现对象重复。
如果您想要多次共享要序列化的对象的传递引用，请转而使用ObjectOutputStream.writeUnshared()。