Writing object to file

My dilemma is i am wanting to write an arraylist to a specific folder within the package mounted in Netbeans. My only problem is I am running on a mac and cannot get to write to correct place. I have tried to use /.../file name etc. It works if i explicitly give the whole path but i do not want to do this as this app will need to transportable to other machines. Any help please.
Thanks
Chad

I tried you suggestion and it works good for getting to the users home folder but I am wanting to contain the resource data file all within the same package. ie... Folder contains all .java files and any resource folders needed. I can get the resource just fine using getClass().getResourceAsStream() but when i write out i get errors. I am using
Is there something like the getClass... that mimics writing out to files. I am also using a mac and only plan on distributing this to other macs only.
Thanks
Chad

Similar Messages

Problem writing object to file

Hi everyone,
I am creating an index by processing text files. No of files are 15000 and index is a B+ Tree. when all files processed and i tried to write it to the file it gives me these errors.
15000 files processed.
writing to disk...
Exception in thread "main" java.lang.StackOverflowError
        at sun.misc.SoftCache.processQueue(SoftCache.java:153)
        at sun.misc.SoftCache.get(SoftCache.java:269)
        at java.io.ObjectStreamClass.lookup(ObjectStreamClass.java:244)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1029)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
        at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:380)
        at java.util.Vector.writeObject(Vector.java:1018)
        at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:890)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1333)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
        at java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1245)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1069)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
        at java.io.ObjectOutputStream.defaultWriteObject(ObjectOutputStream.java:380)
        at java.util.Vector.writeObject(Vector.java:1018)
        at sun.reflect.GeneratedMethodAccessor2.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:585)
        at java.io.ObjectStreamClass.invokeWriteObject(ObjectStreamClass.java:890)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1333)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1341)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1341)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1341)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1341)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
        at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1341)
        at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1284)
        at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1073)
        at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1369)
..........can anyone point out the mistake im doing?
thanks

the B+ Tree is balanced and is perfectly working without writing to the file. and i am using default writeObject() method of ObjectOutputStream.
try {
                            FileOutputStream   f_out   = new   FileOutputStream ("tree.idx");
                            ObjectOutputStream obj_out = new   ObjectOutputStream (new BufferedOutputStream (f_out));
     for (int x = 0, l = files.length; x < l; x++) {
          ProcessTree(files[x].toString());
                System.out.println("Writing main index to the disk...");
                obj_out.writeObject (tree);
                obj_out.flush();
                obj_out.close();
                } catch (Exception e)
      System.out.println (e.toString ());
      System.out.println("Error Writing to Disk!");
    }

Writing Objects to file using Externalizable

Hi,
I'm trying to write an object to file. My sample code is:
public class Junk implements Externalizable{
private static java.util.Random generator = new java.util.Random();
private int answer;
private double[] numbers;
private String thought;
public Junk(String thought) {
this.thought = thought;
answer = 42;
numbers = new double[3+ generator.nextInt(4)];
for (int i=0; i<numbers.length; i++) {
numbers[i] = generator.nextDouble();
public void writeExternal(ObjectOutput stream) throws java.io.IOException {
stream.writeInt(answer);
stream.writeBytes(thought);
for(int i=0; i< numbers.length; i++) {
stream.writeDouble(numbers);
public void readExternal(ObjectInput stream) throws java.io.IOException {
answer = stream.readInt();
String thought = stream.readUTF();
and the class with main() is:
package MyTest;
import java.io.*;
public class SerializeObjects {
public SerializeObjects() {
public static void main(String args[]) {
Junk obj1 = new Junk("A green twig is easily bent.");
Junk obj2 = new Junk("A little knowledge is a dangerous thing.");
Junk obj3 = new Junk("Flies light on lean horses.");
ObjectOutputStream oOut = null;
FileOutputStream fOut = null;
try {
fOut = new FileOutputStream("E:\\FileTest\\test.bin");
oOut = new ObjectOutputStream(fOut);
obj1.writeExternal(oOut);
//obj2.writeExternal(oOut);
} catch (IOException e) {
e.printStackTrace(System.err);
System.exit(1);
try {
oOut.flush();
oOut.close();
fOut.close();
} catch(IOException e) {
e.printStackTrace(System.err);
System.exit(1);
The output I get in test.bin contains some junk ascii codes. The only item that is written correctly in the file is the string.
Is there anyway I can write correct data into a file?
My output needs to be a readable text format file.
Can anyone help please?

obj1.writeExternal(oOut);This should be
oOut.writeObject(obj1);However,
The output I get in test.bin contains some junk ascii
codes. The only item that is written correctly in the
file is the string.If you don't want 'junk' don't use Externalizable and ObjectOutputStream at all, just use PrintStream/PrintWriter.println().

Help me to solve writing object to file ?

what's the happen ? when I write object to file ?
My error is : java.io.NotSerializableException : Sun.awt.image.ToolkitImage
What do I do to expect this error ?
Please help me
Thanks Very much

you need to use ObjectInputStream and ObjectOutput Stream, you can write to file or read from file through readObject and write object.
try this..!!

Writing Objects to File

I have a number of records contained in a vector. Having trouble writing these records to a file. Even trying to write one record, as below, is throwing an exception. The Student class implements serializable and the method main throws IOException
public void saveRecords()
          try
               FileOutputStream outStream = new FileOutputStream ("StudentRecord.dat");
               ObjectOutputStream objOutStream = new ObjectOutputStream (outStream);
               objOutStream.writeObject (student.elementAt(1));
               objOutStream.flush();
               objOutStream.close();
          } // end try
          catch (Throwable e)
               System.out.println ("Error Writing File");
          } // end catch
     } // end saveRecords

Thanks.
I've sorted out the write part. The problem was that a student record object consisted objects of other classes, Name, Address, Course etc. All classes had to implement serializable before I could write the student objects to a file.
Now having trouble with the reloading though. I've input 3 records which were successfully saved. However, on attempting to load these, I get an EOFexception. If I subsequently perform an enquiry on the records after attempting the read operation, records 1 and 3 are accessible but not record 2. Why should I get an EOFexception after 2 of 3 records Here's the code.
public void loadRecords ()
          try
               FileInputStream inStream = new FileInputStream ("StudentRecord1.dat");
               ObjectInputStream objInStream = new ObjectInputStream (inStream);
               do
               student.addElement((PGStudent)objInStream.readObject());
                         } while (objInStream.readObject() != null);
          } // end try
          catch (Throwable e)
               System.out.println ("Error Reading File" + e.toString());
          } // end catch
     } // end loadRecords
     public void saveRecords()
          try
               FileOutputStream outStream = new FileOutputStream ("StudentRecord1.dat");
               ObjectOutputStream objOutStream = new ObjectOutputStream (outStream);
               Enumeration enum = student.elements();
               while(enum.hasMoreElements())
                    objOutStream.writeObject (enum.nextElement());
               objOutStream.flush();
               objOutStream.close();
          } // end try
          catch (Throwable e)
               System.out.println ("Error Writing File" + e.toString());
          } // end catch
     } // end saveRecords

Writing java object into file

Dear Experts,
What is the best way to write java objects into file
1. Using Object Output Stream
or
2.Using ByteArray OutputStream
with Thanks
Panneer

Dear Experts,
What is the best way to write java objects into file
1. Using Object Output Stream
or
2.Using ByteArray OutputStream
with Thanks
PanneerWhat do you mean or? Because I would assume the contents of the byte array stream is coming from an ObjectOutputStream.
Or do you mean to use some sort of buffering...

Expdp with parallel writing in one file at a time on OS

Hi friends,
I am facing a strange issue.Despite giving parallel=x parameter the expdp is writing on only one file on OS level at a time,although it is writing into multiple files sequentially (not concurrently)
While on other servers i see that expdp is able to start writing in multiple files concurrently. Following is the sample log
of my expdp .
++++++++++++++++++++
Export: Release 10.2.0.3.0 - 64bit Production on Friday, 15 April, 2011 3:06:50
Copyright (c) 2003, 2005, Oracle. All rights reserved.
Connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options
Starting "CNVAPPDBO4"."EXPDP_BL1_DOCUMENT": CNVAPPDBO4/********@EXTTKS1 tables=BL1_DOCUMENT DUMPFILE=DUMP1_S:Expdp_BL1_DOCUMENT_%U.dmp LOGFILE=LOG1_S:Expdp_BL1_DOCUMENT.log CONTENT=DATA_ONLY FILESIZE=5G EXCLUDE=INDEX,STATISTICS,CONSTRAINT,GRANT PARALLEL=6 JOB_NAME=Expdp_BL1_DOCUMENT
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 23.93 GB
. . exported "CNVAPPDBO4"."BL1_DOCUMENT" 17.87 GB 150951906 rows
Master table "CNVAPPDBO4"."EXPDP_BL1_DOCUMENT" successfully loaded/unloaded
Dump file set for CNVAPPDBO4.EXPDP_BL1_DOCUMENT is:
/tksmig/load2/oracle/postpaidamd/DUMP1_S/Expdp_BL1_DOCUMENT_01.dmp
/tksmig/load2/oracle/postpaidamd/DUMP1_S/Expdp_BL1_DOCUMENT_02.dmp
/tksmig/load2/oracle/postpaidamd/DUMP1_S/Expdp_BL1_DOCUMENT_03.dmp
/tksmig/load2/oracle/postpaidamd/DUMP1_S/Expdp_BL1_DOCUMENT_04.dmp
Job "CNVAPPDBO4"."EXPDP_BL1_DOCUMENT" successfully completed at 03:23:14
++++++++++++++++++++
uname -aHP-UX ocsmigbrndapp3 B.11.31 U ia64 3522246036 unlimited-user license
Is it hitting any known bug? Please suggest.
regds,
kunwar

PARALLEL always using with DUMPFILE=filename_*%U*.dmp. Did yoy put the same parameter on target server?
PARALLEL clause depend on server resources. If the system resources allow, the number of parallel processes should be set to the number of dump files being created.

How to insert new line char while writing bytes into file

Hello Sir,
Is it possible to insert the new line character in set of String variables and stored them into bytearray ,then finally write into File?
This is the sample code which i tried:
             File f = new File(messagesDir,"msg" + msgnum + ".txt");
             FileOutputStream fout = new FileOutputStream(f);
                String fromString = "From:    "+msg.getFrom()+"\n";
                String toString = "To:     "+msg.getTo()+"\n";
                String dateString = "Sent:    "+msg.getDate()+"\n";
                  String msgString =msg.getBody()+"\n";
                String finalString=fromString+toString+dateString+msgString;
                byte[] msgBytes = finalString.getBytes();
                fout.write(msgBytes);
             fout.close();in the above code , i tried to add the new line as "\n" in end of each string. but when i look into the generated files msg1.txt , it contains some junk char [] .
please provide me the help
regards
venki

but it has still shown the the junk char, its not able
to create the new line in the created file i am afraid
how am i going to get the solution?:(Do not be afraid dear sir. You are obviously using a windows operating system or a mac operating system. On windows a newline is "\r\n" not '\n', and on a mac a newline is '\r', not '\n'. If you make that correction, dear sir, your program will work.
However, there is a better way. First, you probably want to buffer your output if you are going to write more than one time to the file, which will make writing to the file more efficient. In addition, when you buffer your output, you can use the newLine() method of the BufferedWriter object to insert a newline. The newline will be appropriate for the operating system that the program is running on. Here is an example:
File f = new File("C:/TestData/atest.txt");
BufferedWriter out = new BufferedWriter(new FileWriter(f) );
String fromString = "From: Jane";
out.write(fromString);
//Not written to the file until enough data accumulates.
//The data is stored in a buffer until then.
out.newLine();
String toString = "To: Dick";
out.write(toString);
out.newLine();
String dateString = "Sent: October 27, 2006";
out.write(dateString);
out.newLine();
out.close();
//Causes any unwritten data to be flushed from
//the buffer and written to the file.

IO error writing block to file (Apex 4.01, 11gR2, RH 64 bit & Using Gatew

I have Apex 4.01 running on a Linux Red Hat 64 bit server and the database is 11gR2. I'm using the gateway and receiving numerous io errors on files that do not exist in the database. Has any one else experienced this? Should I scrape the gateway and load https ?
File 201 does not exists in the database (error below). I have verified this the files do not exists using ( dba_data_files or dba_temp_files) . Is this a Gateway issue?
I have run dbverify and there are not corruptions within in the database. We have run a disk check on the SAN and there are not issues either.
Example of Error:
===========
</msg>
<msg time='2010-11-09T16:18:25.446-06:00' org_id='oracle' comp_id='rdbms'
client_id='ADMIN:1753485708135952' type='UNKNOWN' level='16'
host_id='houlnxora01d.nblenergy.com' host_addr='10.10.200.26' module='APEX:APPLICATION 4500'
pid='26431'>
<txt>Errors in file /u01/app/oracle/diag/rdbms/bdapx01d/bdapx01d/trace/bdapx01d_s000_26431.trc:
ORA-01114: IO error writing block to file 201 (block # 36609)
ORA-27072: File I/O error
Linux-x86_64 Error: 9: Bad file descriptor
Additional information: 4
Additional information: 36609
Additional information: -1
</txt>
</msg>

Hello,
I think this is a database-related problem which also occurs when using APEX, but I don't think it's caused by APEX.
The error basically says that something is wrong with your filesystem.
I suggest you post this error description to the forum where the experienced dbas could help you more: {forum:id=61}
From what I know, these errors may occur when your filesystem is full or the file was deleted/moved or set offline for some other reason.
You could get a hint for troubleshooting by locating the file on your filesystem:
select file_name
from dba_data_files
where file_id=201;If it actually doesn't exist, something has messed up your data dictionary. You could then try to find out which tablespace and object/s have a hold on that file:
select
   owner,
   tablespace_name,
   segment_type,
   segment_name
from
   dba_extents
where
   file_id = 201
and
   block_id = 36609;I hope it's just the "disk full"-case.
-Udo

File.WriteContents writing to hidden files?

I have noticed that File.WriteContents writes to premade files or makes files but i was wondering if there was something that would allow writing to hidden files, is this possible?

First NOTE what JJ said.
Supposed a testfile "C:\Program Files\Microsoft\Small Basic\Projects\TestFile.txt" (here with space(s) in path)
and a original set attribute of +H for the testfile, you could use:
'------------- SNIP -------------
qu = Text.GetCharacter(34)
txtFile = "C:\Program Files\Microsoft\Small Basic\Projects\TestFile.txt"
txt = "My Text to write"
cmdLine = "-H " +qu+ txtFile +qu '' clears the 'hidden / H' attribute only
cmdLine = qu+ cmdLine +qu
LDProcess.Start("attrib.exe", cmdLine)
res = File.WriteContents(txtFile, txt)
TextWindow.WriteLine(res)
' -------- SNAP -----------
Depending on the set attributes (can be checked with
attr = LDShell.GetDetail(txtFile, 6) '' or
'attr2 = LDShell.GetDetail(txtFile, "Attributes") ' on an
engl. System
you will have to ev. temporary set back others as well. eg. 'attrib.exe -H -S -R txtFile',
remember the original attribute(s) and, after writing to txtFile,
set back again (eg. attrib.exe +H +S +R txtFile) to the original attributes.
PS: If you are on SB 1.0 there is Data extension's 'FilePlus' object, which supports some methods for attributes (like .ContainsAttiribute, AddAttiribute, RemoveAttiribute). Perhaps further ('old') extensions that support attributes (like 'Fremy' etx ??
etc), but unfortunaltely the don't work any more for SB 1.1.
At any rate: You should KNOW what you are doing !!

How to sync writing to a file?

Hi all,
I'm implementing a simple line logger for my web applications.
Basically, I have some class with a "write" method, that appends a line of text into a certain file.
All of my web apps log into the same file (by design).
How do I make sure writing to the file is synchronized?
The web apps cannot share logger objects between them (not even singletons, correct?) so using the 'synchronized' qualifier for the 'write' method won't work because each web app has its own instance of the logger object.
Also, FileLock won't work since all web apps "live" inside the same JVM (accoding to javadoc, FileLock is not suitable for syncing file-writes by different threads within the same JVM).
I've looked up the forum for answers to these questions, but non of the threads on this topic provided any leads...
Any ideas?

hii...
can sum1 plz tell me how to replace bytes in a file?
i've used randomaccess to open the file....read is
contents and write back to it at the desired
locations using seek()...however at some position if
i wish to read the data and replace it with new data
at exactly the same location...how can i do it??
bye.i had already mentioned my problem....actually i want to read a record from a file and then update it at the same location in the file...so i need to replace it(or delete the record and re-write the new info).

How can i save object in file ?

For example I have some object in the memory, and i want to save it on the disk, and after i'm going load this object in memory and work with him...How can i do it ?
May be I must use JavaSpaces technology (but i don't enought knows this) ?
Please help me.
[email protected]

Serializing an Object:
try
ObjectOutputStream myOutput ObjectOutputStream(new FileOutputStream("objects.out"));
myOutput.writeObject("Hello! How are you on this very fine day?");
out.close()
catch(IOException e)
System.err.println("Doh! You're probably writing to a file that you don't have permissions to access!");
catch(ClassNotFoundException e)
System.err.println("You should only get this if you're using some strange reflection stuff, or just try to output something that doesn't exist.. I don't really know why the compiler wouldn't catch this error instead otherwise");
Getting that object back:
try
ObjectInputStream inObjects = new ObjectInputStream(new FileInputStream("objects.out"));
String myObj = (String)in.readObject();
System.out.println(myObj);
Pretty simple. If you want to be more practical, and store more than one type of object in that file, you can use relfection:
-Jason Thomas.

Why would i write objects to file?

Im seeing a lot of about wrinting objects to file, but �til now, i don�t know why.
I�d be glad if you guys say sometinhg about it: if you use, why.
Maybe i shloud be using , but i did�t know why...
Tks.
Bruno

Mostly the "file" is not really a file, but a communications channel between two java processes. I worked on a client/server system that put serialised java objects in HTTP messages. Worked great.
Or you might temporarily cache objects to a file for memory reasons (eg: a web server that handles thousands of live connecitons). Writing to a file for persistsence is of limited use because little things can make them un-deserialisable. Better off using XML for persistence.

CS5 is opening raw files as a smart object to files im currently working

I just bough new CS 5 and find this big error. When i open raw file in Camera Raw and i have opened some jpg in CS5, it always opened as a smart object to this small jpg i have opened before. The same is doing my CS 5 when i drag some file from desktop, it always ended as a smart object in file im currently working with. Normaly it has to open as a new file not as a smart object in this file im already working with.

How are you opening your RAW files? If you are dragging and dropping them onto Photoshop, on top of an already opened file's workspace - all files will be placed as smart objects. If you drag the files to anywhere else in the interface, for instance the grey area on top of the workspace, they should open as usual. If you are opening them via Bridge or by double-clicking them in Explore, they should open as normal.

Error in writing to export file

Hi,
I am getting the below error on running export:-
EXP-00002: error in writing to export file
The query is as given below:-
exp cam3_mpcb2/cam3_mpcb2@ORA10G file='c:\MPCB_cam_20120113.dmp' log='c:\MPCB_20120113.log'
CAn i overcome this error by adding "ignore" at the end of the query or how can i modify the above query ?

Are there any other error messages that accompany the one you posted?
EXP-00002: error in writing to export file
Cause: Export could not write to the export file, probably because of a device error. This message is usually followed by a device message from the operating system.
Action: Take appropriate action to restore the device. Do you have permissions to write to this location?

Writing object to file

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