從java中的二進制文件中讀取對象

我有序列化對象並將其存儲在二進制文件中的功能，也是另一個對象，用於統計目前爲止我已存儲在文件中的對象數量，因此我可以使用計數器稍後再通過該文件並反序列化並閱讀它。這是我寫的功能：從java中的二進制文件中讀取對象

Class2 dad = new Class2(DadName.getText(), DadLastName.getText()); 

Class1 son = new Class1(FirstName.getText(), dad, "Session"); 

// Write object to file 
FileOutputStream outStream = new FileOutputStream(new File("MainStore.dat"), true); 
ObjectOutputStream objectOutputFile = new ObjectOutputStream(outStream); 
objectOutputFile.writeObject(son); 
objectOutputFile.close(); 


// Update the objectcounter file by 
// Maintenance is a class I use just to save object contain information about number of files,increase them, decrease them. 

Maintenance check = new Maintenance(); 
FileInputStream inStream = new FileInputStream("Counter.dat"); 
ObjectInputStream objectInput = new ObjectInputStream(inStream); 
check = (Maintenance) objectInput.readObject(); 
inStream.close(); 

check.increaseObject(); 

FileOutputStream outStream1 = new FileOutputStream("Counter.dat"); 
ObjectOutputStream objectOutputFile1 = new ObjectOutputStream(outStream1); 

objectOutputFile1.writeObject(check); 
objectOutputFile1.close();

先前的功能工作得很好，下一步就是函數讀取讀取的對象從文件回來，我用Counter.dat看到存儲在MainStore對象的數量。 dat，它給了我正確的編號。這裏是讀功能：

// Read Counter file to know how many stored objects to go through them 
Maintenance check = new Maintenance(); 
FileInputStream inStream = new FileInputStream("Counter.dat"); 
ObjectInputStream objectInput = new ObjectInputStream(inStream); 
check = (Maintenance) objectInput.readObject(); 
int Counter1 = check.getObjectsNumber(); // function I created in the Maintenance class to return number of object stored 
inStream.close(); 


// Read the stored objects 
//here is my problem begin 

FileInputStream inStream2 = new FileInputStream("MainStore.dat"); 
ObjectInputStream objectInputFile = new ObjectInputStream(inStream2); 

// Create array of objects 
Class1[] arrayOfObjects = new Class1[Counter1]; 

// Read the serialized objects from the file. 
for (int i = 0; i < Counter1; i++) { 
arrayOfObjects[i] = (Class1) objectInputFile.readObject(); // here is the error pointed by compiler 
} 
objectInputFile.close(); 

for (int i = 0; i < 2; i++) { 
// here I should have array of all objects ready to read details 

}

一切都看起來不錯，除了最後一位「//讀取從序列化對象」。它給了我這個錯誤

Caused by: java.io.StreamCorruptedException: invalid type code: AC 
    at java.io.ObjectInputStream.readObject0(Unknown Source) 
    at java.io.ObjectInputStream.readObject(Unknown Source) 
    at registerController.CheckPlaceAvailabilityAction(registerController.java:120) 
    ... 58 more

，當我只有讀一個對象來測試它，它的工作完美，並返回第一個存儲的對象對我來說，錯誤發生了，當我嘗試讀取所有存儲的對象。

來源

2016-12-25 Hussein

如果可以，您可能需要發佈MVCE（http://stackoverflow.com/help/mcve）。 –

你爲什麼要堅持櫃檯？你確定你的文件在測試過程中沒有被損壞嗎？我建議刪除它並重新開始一個新文件。 – JimmyB

顯然，你不能像你一樣透明地連接/追加ObjectOutputStreams。

參見the docs：

[該]構造序列化流報頭寫入底層流

因此，一個新的數據流將首先寫一些頭，這將需要一個新的輸入流讀書。否則，輸入流會嘗試將標題作爲序列化對象讀取，並會失敗，因爲這些標題不是有效的序列化對象數據。

來源

2016-12-25 21:07:22 JimmyB

從java中的二進制文件中讀取對象

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