Question

我的Java App遇到了一些问题。我有2帧，大型机称为MasterFrame。 MasterFrame包含一个JList + 3按钮。

按钮1可以将块形状添加到JList，这将调用名为BlockFrame的第2帧。块形状是存储在ArrayList shapecollection中的对象。

MasterFrame还包含一个Save按钮，用于将对象存储在名为“test.txt”的.txt文件中。

MasterFrame还包含一个Load按钮，它将打开.txt文件“test.txt”，读取文件中的对象并将对象设置回JList。这就是实际出错的地方。保存功能有效，我不太确定加载方法。它似乎实际上正在读取我的.txt文件中的对象，但它不会把它放回我的Jlist中。

load方法可能不错，但是读取对象并将它们设置回JList可能会有问题。我很高兴如果有人离开你们可以帮我一把:)

import java.io.*;

// My File IO Class
public class ShapeIOController {
private String filename;


public ShapeIOController(){
filename= "C:\\Users\\Lars\\Desktop\\test.txt";
}

// The Save method which will save all my created blocks in "test.txt" file
public void save(ShapeCollection shapecollection){

    try {
    ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(filename)); 
    out.writeObject(shapecollection);
    out.close();
    }
    catch( IOException e){
    System.out.println("Error occured when trying to open file" + filename);
    e.printStackTrace();
    }
}

// The open file method which will open "test.txt" file, 
// read it's objects and return a ArrayList of shapes "shapecollection"
public ShapeCollection open(ShapeCollection shapecollection){
     try{
     ObjectInputStream in = new ObjectInputStream(new FileInputStream(filename));
     shapecollection= (ShapeCollection) in.readObject();
     in.close();
     }
     catch (ClassNotFoundException e ) {
     System.out.println("Unknown class by reading file" + filename);
     }
     catch ( IOException e ) {
     System.out.println("Error occured when trying to open file " + filename);
     e.printStackTrace();
     }

shapecollection.giveCollection();
return shapecollection;
    }
}

// The code for the save button which works
 private void SaveShapeButtonActionPerformed(java.awt.event.ActionEvent evt) {                                                  
    shapeiocontroller.save(shapecontroller.getShapeCollection());
} 

// The code where it probably is going wrong
 private void LoadShapeButtonActionPerformed(java.awt.event.ActionEvent evt) {
    for(int i = 0; i < shapecontroller.getShapeCollection().giveCollection().size(); i++){
    listModel.addElement(shapecontroller.getShapeCollection().giveShape(i).toString());
    InfoShapeJList.setModel(listModel);
    shapeiocontroller.open(shapecontroller.getShapeCollection());
    }   
}

// List of methods LoadShapeButtonActionPerformed is using:

// getShapeCollection()
public ShapeCollection getShapeCollection() {
    return shapecollection;
}

// giveCollection()
public ArrayList<Shape> giveCollection(){
   return shapecollection;
}

// giveShape()
 public Shape giveShape(int index){
    return shapecollection.get(index);     
 }

// toString()
 public String toString(){
    return "Block: " + length + " " + width + " " + height;
}

来自.txt文件的对象不会写入我的Jlist

0 个答案: