Java 无法将RMI客户端连接到主机,由EOFEException引起的解组异常
我在netbeans中打开了以下文件 服务器:Java 无法将RMI客户端连接到主机,由EOFEException引起的解组异常,java,exception,rmi,eofexception,Java,Exception,Rmi,Eofexception,我在netbeans中打开了以下文件 服务器: package server; import java.rmi.*; import java.rmi.registry.*; import java.rmi.server.*; import java.sql.*; public class Server implements ServerInterface { private Connection con; private Statement st; public
package server;
import java.rmi.*;
import java.rmi.registry.*;
import java.rmi.server.*;
import java.sql.*;
public class Server implements ServerInterface {
private Connection con;
private Statement st;
public Server(String db, String username, String password) {
try {
con = DriverManager.getConnection(db, username, password);
st = con.createStatement();
} catch(Exception e) {
System.out.println(e);
}
}
public static void main(String[] args) {
try {
Server server = new Server("jdbc:mysql://localhost:3306/db", "root", "password");
System.setSecurityManager(new RMISecurityManager());
ServerInterface stub = (ServerInterface) UnicastRemoteObject.exportObject(server, 0);
Registry registry = LocateRegistry.createRegistry(1099);
registry.rebind("Server", stub);
} catch (Exception e) {
System.out.println(e);
}
}
public boolean authenticate(String username, String password) {
try {
String query = "SELECT * FROM staff WHERE staff_id ='" + username + "' AND password = '" + password + "'";
ResultSet rs = st.executeQuery(query);
if(rs.next()) {
return true;
} else {
return false;
}
} catch(Exception e) {
System.out.println(e);
}
return false;
}
}
客户:
package client;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.rmi.registry.*;
public class Client extends JFrame implements ActionListener {
JFrame main;
JPanel loginPanel;
JPanel contentPanel;
JButton horse;
JButton staff;
JButton loan;
JButton treatment_record;
JButton work_record;
JButton contact;
JButton loaner;
JButton field_visit;
JButton login;
JTextField username;
JPasswordField password;
String usernameString;
String passwordString;
public Client() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception e) {
System.out.println(e);
}
loginPanel = new JPanel();
contentPanel = new JPanel();
login = new JButton("Login");
username = new JTextField(20);
password = new JPasswordField(20);
horse = new JButton("Horses");
staff = new JButton("Staff");
loan = new JButton("Current Loans");
treatment_record = new JButton("Treatment Records");
work_record = new JButton("Work Records");
contact = new JButton("Contacts");
loaner = new JButton("Loaners");
field_visit = new JButton("Field Visits");
horse.addActionListener(this);
staff.addActionListener(this);
loan.addActionListener(this);
treatment_record.addActionListener(this);
work_record.addActionListener(this);
contact.addActionListener(this);
loaner.addActionListener(this);
field_visit.addActionListener(this);
login.addActionListener(this);
loginPanel.add(new JLabel("Username"));
loginPanel.add(username);
loginPanel.add(new JLabel("Password"));
loginPanel.add(password);
loginPanel.add(login);
contentPanel.add(horse);
contentPanel.add(staff);
contentPanel.add(loan);
contentPanel.add(treatment_record);
contentPanel.add(work_record);
contentPanel.add(contact);
contentPanel.add(loaner);
contentPanel.add(field_visit);
contentPanel.setLayout(new GridLayout(0, 3));
loginPanel.setLayout(new GridLayout(0, 2));
contentPanel.setSize(800, 600);
this.setTitle("TRC Database");
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setContentPane(loginPanel);
this.setVisible(true);
this.pack();
}
public static void main(String[] args) {
new Client();
try {
Registry registry = LocateRegistry.getRegistry();
ServerInterface stub = (ServerInterface) registry.lookup("Server");
} catch (Exception e) {
System.out.println(e);
}
}
public void actionPerformed(ActionEvent ae) {
if (ae.getSource() == login) {
usernameString = username.getText();
passwordString = password.getText();
JOptionPane.showMessageDialog(null, "Button pressed!");
}
this.revalidate();
this.pack();
}
}
客户端存根:
package client;
import java.rmi.*;
public interface ServerInterface extends Remote {
public boolean authenticate(String username, String password) throws RemoteException;
}
package server;
import java.rmi.*;
public interface ServerInterface extends Remote {
public boolean authenticate(String username, String password) throws RemoteException;
}
服务器端存根:
package client;
import java.rmi.*;
public interface ServerInterface extends Remote {
public boolean authenticate(String username, String password) throws RemoteException;
}
package server;
import java.rmi.*;
public interface ServerInterface extends Remote {
public boolean authenticate(String username, String password) throws RemoteException;
}
server类执行良好,但运行client类会出现以下错误:
java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is:
java.io.EOFException
堆栈跟踪:
java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is:
java.io.EOFException
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:227)
at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:377)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at client.Client.main(Client.java:88)
Caused by: java.io.EOFException
at java.io.DataInputStream.readByte(DataInputStream.java:267)
at sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:213)
... 3 more
我见过很多人有相同的错误信息,但我找不到任何解决方案张贴到它。这里有人能帮我吗?这通常是由同级的沙盒权限问题引起的。摆脱安全经理。这里不需要它。另一个原因可能是您要传输的对象实际上不可序列化。不幸的是,服务器RMI在默认情况下不记录这一点。在返回对象之前,最好在服务器端进行检查:
try {
new ObjectOutputStream(new ByteArrayOutputStream()).writeObject(object);
} catch (Exception e) {
logger.error("serializable check failed", e);
}
删除安全管理器会导致:java.rmi.unmarshallexception:error unmarshalling return;嵌套异常为:java.lang.ClassNotFoundException:server.ServerInterface(没有禁用安全管理器:RMI类加载器),因此必须有两个版本的ServerInterface。因为客户机连一个都没有。它们必须是相同的:相同的名称,相同的内容,相同的包,最好是相同的二进制文件。谢谢,就是这样,包的名称是不同的@EJP我也会遇到同样的错误,但有时在RMI对象上调用相同的函数之后。这也是因为安全经理吗?@Uday可能。在没有安全管理器的情况下尝试同行,您将自己看到。