ngoại lệ trong ứng dụng GWT RPC

Question

Tôi đang sử dụng GWT RPC & Hibernate để chèn và truy xuất dữ liệu từ MySQL bằng môi trường nhật thực. Tôi đã viết hai phương thức trong giao diện dịch vụ để chèn & truy xuất dữ liệu từ một bảng MySQL duy nhất.

Chương trình đang chạy tốt nhưng nó đang tăng ngoại lệ này.

Exception in thread "UnitCacheLoader" java.lang.RuntimeException: Unable to read from byte cache 
    at com.google.gwt.dev.util.DiskCache.transferFromStream(DiskCache.java:166) 
    at com.google.gwt.dev.util.DiskCacheToken.readObject(DiskCacheToken.java:87) 
    at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
    at java.lang.reflect.Method.invoke(Unknown Source) 
    at java.io.ObjectStreamClass.invokeReadObject(Unknown Source) 
    at java.io.ObjectInputStream.readSerialData(Unknown Source) 
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source) 
    at java.io.ObjectInputStream.readObject0(Unknown Source) 
    at java.io.ObjectInputStream.defaultReadFields(Unknown Source) 
    at java.io.ObjectInputStream.readSerialData(Unknown Source) 
    at java.io.ObjectInputStream.readOrdinaryObject(Unknown Source) 
    at java.io.ObjectInputStream.readObject0(Unknown Source) 
    at java.io.ObjectInputStream.readObject(Unknown Source) 
    at com.google.gwt.dev.javac.PersistentUnitCache.loadUnitMap(PersistentUnitCache.java:493) 
    at com.google.gwt.dev.javac.PersistentUnitCache.access$000(PersistentUnitCache.java:92) 
    at com.google.gwt.dev.javac.PersistentUnitCache$UnitCacheMapLoader.run(PersistentUnitCache.java:122) 
Caused by: java.io.StreamCorruptedException: unexpected EOF in middle of data block 
    at java.io.ObjectInputStream$BlockDataInputStream.refill(Unknown Source) 
    at java.io.ObjectInputStream$BlockDataInputStream.read(Unknown Source) 
    at java.io.ObjectInputStream.read(Unknown Source) 
    at java.io.InputStream.read(Unknown Source) 
    at com.google.gwt.dev.util.DiskCache.transferFromStream(DiskCache.java:154) 
    ... 16 more 

ServiceImpl lớp:

package rpctest.server; 

import java.util.ArrayList; 
import java.util.Iterator; 
import java.util.List; 

import com.google.gwt.user.server.rpc.RemoteServiceServlet; 
//import com.hib.HibernateUtil; 

import org.hibernate.Session; 
import org.hibernate.Transaction; 
import rpctest.shared.User; 
import rpctest.client.RpctestService; 

public class RpctestServiceImpl extends RemoteServiceServlet implements RpctestService { 

     public String addUser(String name1, String name2) 
      throws IllegalArgumentException { 

       Transaction trns = null; 
       Session session = HibernateUtil.getSessionFactory().openSession(); 
       try { 
       trns = session.beginTransaction(); 

       User user = new User(); 

       user.setFirstName(name1); 
       user.setLastName(name2); 

       session.save(user); 

       session.getTransaction().commit(); 
       } catch (RuntimeException e) { 
       if(trns != null){ 
       trns.rollback(); 
       } 
       e.printStackTrace(); 
       } finally{ 
       session.flush(); 
       session.close(); 
       } 

     return name1+name2; // to test flextable entris only 
    } 

    @Override 
    public User[] getUser() 
      { 

       List<User> getUser = null; 

       Transaction trns = null; 
       Session session = HibernateUtil.getSessionFactory().openSession(); 
       try { 
       trns = session.beginTransaction(); 
       getUser = session.createQuery("from User").list(); 

       //* for (Iterator<User> iter = getUser.iterator(); iter.hasNext();) 
       //{ 
       //User user = iter.next(); 
       // 
       //*}    

       trns.commit(); 
       } catch (RuntimeException e) { 
       if(trns != null){ 
       trns.rollback(); 
       } 
       e.printStackTrace(); 
       } finally{ 
       session.flush(); 
       session.close(); 
      } 
       return getUser.toArray(new User[getUser.size()]); 
     } 
} 

entrypoint lớp:

package rpctest.client; 

import java.util.ArrayList; 

import rpctest.shared.User; 
import rpctest.shared.FieldVerifier; 
import com.google.gwt.core.client.EntryPoint; 
import com.google.gwt.core.client.GWT; 
import com.google.gwt.event.dom.client.ClickEvent; 
import com.google.gwt.event.dom.client.ClickHandler; 
import com.google.gwt.event.dom.client.KeyCodes; 
import com.google.gwt.event.dom.client.KeyPressEvent; 
import com.google.gwt.event.dom.client.KeyUpEvent; 
import com.google.gwt.event.dom.client.KeyUpHandler; 
import com.google.gwt.user.client.Window; 
import com.google.gwt.user.client.rpc.AsyncCallback; 
import com.google.gwt.user.client.ui.Button; 
import com.google.gwt.user.client.ui.DialogBox; 
import com.google.gwt.user.client.ui.FlexTable; 
import com.google.gwt.user.client.ui.HTML; 
import com.google.gwt.user.client.ui.HorizontalPanel; 
import com.google.gwt.user.client.ui.Label; 
import com.google.gwt.user.client.ui.RootPanel; 
import com.google.gwt.user.client.ui.TextBox; 
import com.google.gwt.user.client.ui.VerticalPanel; 

import com.google.gwt.event.dom.client.KeyCodes; 
import com.google.gwt.event.dom.client.KeyPressEvent; 
import com.google.gwt.event.dom.client.KeyPressHandler; 

/** 
* Entry point classes define <code>onModuleLoad()</code>. 
*/ 
public class Rpctest implements EntryPoint { 

    final TextBox firstName = new TextBox(); 
    final TextBox lastName = new TextBox(); 
    final Button ans = new Button("Add User"); 
    //final Label label1 = new Label("First Name"); 
    //final Label label2 = new Label("Last Name"); 
    private FlexTable userFlexTable = new FlexTable(); 
    //final Label errorLabel = new Label(); 

    private VerticalPanel mainpanel = new VerticalPanel(); 
    private HorizontalPanel addpanel1 = new HorizontalPanel(); 
    private HorizontalPanel addpanel2 = new HorizontalPanel(); 
    private final RpctestServiceAsync calNumbers = GWT 
      .create(RpctestService.class); 

    /** 
    * This is the entry point method. 
    */ 
    public void onModuleLoad() { 

     userFlexTable.setText(0, 0, "User ID"); 
     userFlexTable.setText(0, 1, "First Name"); 
     userFlexTable.setText(0, 2, "Second Name"); 
     userFlexTable.setText(0, 3, "Remove"); 

     //add input boxes to panel 
     addpanel1.add(firstName); 
     addpanel1.add(lastName); 

     firstName.setFocus(true); 

     //add input 
     mainpanel.add(userFlexTable); 
     mainpanel.add(addpanel1); 
     addpanel1.add(ans); 

     ans.addClickHandler(new ClickHandler() { 
      @Override 
      public void onClick(ClickEvent event) { 
         addStock();     
      } 
     }); 

     lastName.addKeyPressHandler(new KeyPressHandler() { 
       public void onKeyPress(KeyPressEvent event) { 
        if (event.getCharCode() == KeyCodes.KEY_ENTER) { 
         addStock(); 
        } 
       } 
       }); 

     RootPanel.get().add(mainpanel); 
     getUser(); 
    } 

private void addStock(){ 

     String name1 = firstName.getValue(); 
     // Stock code must be between 1 and 10 chars that are numbers, letters, or dots. 
     /*if (!name1.matches("^[0-9A-Z\\.]{1,10}$")) { 
      Window.alert("'" + name1 + "' is not a valid name."); 
      firstName.selectAll(); 
      return; 
     }*/ 
     firstName.setValue(""); 

     String name2 = lastName.getValue(); 
     /*if (!name2.matches("^[0-9A-Z\\.]{1,10}$")) { 
       Window.alert("'" + name1 + "' is not a valid name."); 
       lastName.selectAll(); 
       return; 
      }*/ 
     lastName.setValue(""); 
     firstName.setFocus(true); 

     calNumbers.addUser(name1,name2, 
      new AsyncCallback<String>() { 
      public void onFailure(Throwable caught) { 
       // Show the RPC error message to the user 
        Window.alert("check your inputs"); 
       } 

      @Override 
      public void onSuccess(String result) { 
      // TODO Auto-generated method stub 
       // Add the user to the table. 
       // int row = userFlexTable.getRowCount(); 
       // userFlexTable.setText(row, 1, result); 

       getUser(); 
      } 
     }); 
    } 

private void getUser(){ 

     calNumbers.getUser(new AsyncCallback<User[]>() { 
      public void onFailure(Throwable caught) { 
       // Show the RPC error message to the user 
        Window.alert("Problem in database connection"); 
       } 

      @Override 
      public void onSuccess(User[] result) { 
       // TODO Auto-generated method stub 
       for(int i = 0; i < result.length; i ++) 
        { 
        //String s = result[i].getFirstName();    
        int row = userFlexTable.getRowCount(); 
        userFlexTable.setText(row, 0, result[i].getId().toString()); 
        userFlexTable.setText(row, 1, result[i].getFirstName()); 
        userFlexTable.setText(row, 2, result[i].getLastName()); 
         } 



      } 
     }); 

     } 
} 

Answer 1

Bạn có nghĩa là mã của bạn hoạt động tốt nhưng bạn thấy ngoại lệ này trong nhật ký? Ngoại lệ về cơ bản có nghĩa là bộ đệm biên dịch không tải được vì lý do nào đó. Nhiều khả năng bộ nhớ cache đã bị hỏng vì một lý do nào đó, vì vậy hãy thử xóa thư mục gwt-UnitCache khỏi dự án của bạn, điều này sẽ giúp ích.

Answer 2

Có lẽ đó là một thông báo lỗi và bạn nhấn vào nút Yes: