I have a trouble with reading multiple objects from InputStream(i.e. from file). I receive the exception:
java.io.StreamCorruptedException: invalid type code: AC
at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1379)
at java.io.ObjectInputStream.readObject(ObjectInputStream.java:371)
at com.socket.Client.readFromFile(Client.java:63)
at com.socket.Client.main(Client.java:44)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
I have managed to read/write only one object, it's OK. I can write many objects, it's OK too. But I cannot read more than one object from file. Why does it happen so?
EDIT:
NB! It seems I have faced with the problem of implementing of List in Externalazible class. How to implement it correcly?
My 'Main' code:
public class Client {
public static void main(String[] args) {
if (args[0] == null || args[1] == null) {
System.out.println("No arguments entered!");
System.exit(0);
}
try (Socket clientSocket = new Socket("localhost", 3000);
OutputStream outbound = clientSocket.getOutputStream();
BufferedReader inbound = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));) {
outbound.write((args[0] + "\n").getBytes());
outbound.write("End\n".getBytes());
List<StockQuote> stockQuotes = new ArrayList<>();
String quote;
while (true) {
quote = inbound.readLine();
if (quote != null && quote.equals("End"))
break;
stockQuotes.add(new StockQuote(args[0], new Double(quote)));
}
writeInFile(args[1], stockQuotes);
stockQuotes.clear();
stockQuotes = readFromFile(args[1]);
if (stockQuotes != null)
for (StockQuote stockQuote : stockQuotes)
System.out.println("The " + stockQuote.getSymbol() + " price is " + stockQuote.getPrice());
} catch (UnknownHostException e) {
System.out.println("No such host available!");
} catch (IOException e) {
System.out.println("Server not reachable or down!!");
}
}
private static List<StockQuote> readFromFile(String filename) {
File file = new File(filename);
try (ObjectInputStream readFromFile = new ObjectInputStream(new BufferedInputStream(new FileInputStream(file)));) {
return (List<StockQuote>) readFromFile.readObject();
} catch (FileNotFoundException e) {
System.out.println("'" + filename + "' is not found in " + file.getPath());
} catch (IOException e) {
e.printStackTrace();
System.out.println("Something gone wrong in the process of reading from '" + file + "'");
} catch (ClassNotFoundException e) {
System.out.println("Cast to class is wrong!");
}
return null;
}
private static void writeInFile(String filename, List<StockQuote> stockQuotes) {
File file = new File(filename);
try (ObjectOutputStream writeInFile = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream(file, true)));) {
writeInFile.writeObject(stockQuotes);
} catch (FileNotFoundException e) {
System.out.println("'" + filename + "' is not found in " + file.getPath());
} catch (IOException e) {
System.out.println("Something gone wrong in the process of writing to '" + file + "'");
}
}
}
Externalizable 'StockQuote' class:
public class StockQuote implements Externalizable {
private String symbol;
private double price;
private List<StockQuote> stockQuoteList;
public StockQuote() {
}
public StockQuote(String symbol, double price) {
this.symbol = symbol;
this.price = price;
}
public String getSymbol() {
return symbol;
}
public void setSymbol(String symbol) {
this.symbol = symbol;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
@Override
public void writeExternal(ObjectOutput out) throws IOException {
out.writeObject(stockQuoteList);
}
@Override
public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
stockQuoteList = (List<StockQuote>) in.readObject();
}
}
Result:
As the result, I receive something like "The null price is 0.0". It says that I serialize my List but my Objects inside it are not serialized, why?
NB!
And could you take me one more tip, how is better to write strings, list and so on in Externalizable classes as out.writeObject or there is beter way to do it?
