I was trying to flush data in a file in my local machine to response. But at some point I get an IndexOutOfBoundsException.
FileInputStream inputStream = new FileInputStream(downloadFile);
OutputStream outStream = response.getOutputStream();
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer, 0, 4096)) != -1) {
outStream.write(buffer, 0, bytesRead);
}
inputStream.close();
outStream.close();
The above code is what I was trying. The downloadFile path given is correct and it works till the while loop. But then the IndexOutOfBoundsException occurs. I tried it with inputStream.read(buffer) but that didn't work.
Give code is working perfectlly; since there is no information is given regarding the response object I have modify the OutputStream to FileOutputStream; just to test.
Below code segment is working perfectly.
public class Test
{
public static void main(String args[]) throws IOException
{
FileInputStream inputStream = new FileInputStream("C:\\readme.txt");
FileOutputStream outputStream = new FileOutputStream("D:\\readme1.txt");
//OutputStream outStream = response.getOutputStream();
byte[] buffer = new byte[4096];
int bytesRead = -1;
while ((bytesRead = inputStream.read(buffer, 0, 4096)) != -1) {
outputStream.write(buffer, 0, bytesRead);
}
inputStream.close();
outputStream.close();
}
}
Related
I am working on reading a file and write same file, but the problem is the downloaded file is 2kb larger than input original file.
Some piece of code
#Override
public void run() {
try {
BufferedInputStream bis;
ArrayList<byte[]> al =new ArrayList<byte[]>();
File file = new File(Environment.getExternalStorageDirectory(), "test.mp3");
byte[] bytes = new byte[2048];
bis = new BufferedInputStream(new FileInputStream(file));
OutputStream os = socket.getOutputStream();
int read ;
int fileSize = (int) file.length();
int readlen=1024;
while (fileSize>0) {
if(fileSize<1024){
readlen=fileSize;
System.out.println("Hello.........");
}
bytes=new byte[readlen];
read = bis.read(bytes, 0, readlen);
fileSize-=read;
al.add(bytes);
}
ObjectOutputStream out1 = new ObjectOutputStream(new FileOutputStream(Environment.getExternalStorageDirectory()+"/newfile.mp3"));
for(int ii=1;ii<al.size();ii++){
out1.write(al.get(ii));
// out1.flush();
}
out1.close();
File file1 = new File(Environment.getExternalStorageDirectory(), "newfile.mp3");
Don't use an ObjectOutputStream. Just use the FileOutputStream, or a BufferedOutputStream wrapped around it.
The correct way to copy streams in Java is as follows:
byte[] buffer = new byte[8192]; // or more, or even less, anything > 0
int count;
while ((count = in.read(buffer)) > 0)
{
out.write(buffer, 0, count);
}
out.close();
Note that you don't need a buffer the size of the input, and you don't need to read the entire input before writing any of the output.
Wish I had $1 for every time I've posted this.
I think you should use ByteArrayOutputStream not an ObjectOutputStream.
I belive this is not a raw code, but the parts of the code, placed in different procedures, otherwise it is meaningless.
For example, in case you want to stream some data from a file, process this data, and then write the data to another file.
BufferedInputStream bis = null;
ByteArrayOutputStream al = new ByteArrayOutputStream();
FileOutputStream out1 = null;
byte[] bytes;
try {
File file = new File("testfrom.mp3");
bis = new BufferedInputStream(new FileInputStream(file));
int fileSize = (int) file.length();
int readLen = 1024;
bytes = new byte[readLen];
while (fileSize > 0) {
if (fileSize < readLen) {
readLen = fileSize;
}
bis.read(bytes, 0, readLen);
al.write(bytes, 0, readLen);
fileSize -= readLen;
}
bis.close();
} catch (IOException e){
e.printStackTrace();
}
//proceed the data from al here
//...
//finish to proceed
try {
out1 = new FileOutputStream("testto.mp3");
al.writeTo(out1);
out1.close();
} catch (IOException e){
e.printStackTrace();
}
Don't forget to use try-catch directives where it needed
http://codeinventions.blogspot.ru/2014/08/creating-file-from-bytearrayoutputstrea.html
I'm having issues sending a file from one person to another in my program, I get a "invalid stream header" error. Here is the code for sending and receiving the file, respectively:
private void sendFile(Socket socket, File file) throws IOException
{
int bytesRead;
byte[] buffer;
FileInputStream input;
OutputStream output;
buffer = new byte[(int)file.length()];
input = new FileInputStream(file);
output = socket.getOutputStream();
bytesRead = input.read(buffer);
while(bytesRead > 0)
{
output.write(buffer,0,bytesRead);
bytesRead = input.read(buffer);
}
input.close();
output.close();
}
private void receiveFile(Socket socket, File file) throws IOException
{
int bytesRead;
byte[] buffer;
InputStream input;
FileOutputStream output;
buffer = new byte[(int)file.length()];
output = new FileOutputStream(file);
input = socket.getInputStream();
bytesRead = input.read(buffer);
while(bytesRead > 0)
{
output.write(buffer,0,bytesRead);
bytesRead = input.read(buffer);
}
input.close();
output.close();
}
I've already read up on Stack and everything I've tried hasn't fixed it. Does anyone have any ideas? Thanks!
Exact error is:
java.io.StreamCorruptedException: invalid stream header: 3C736372
at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:804)
at java.io.ObjectInputStream.<init>(ObjectInputStream.java:299)
at Message.readMessageFrom(Message.java:32)
at Server$Handler.run(Server.java:220)
at java.lang.Thread.run(Thread.java:744)
I'm trying to write the inputstream image to OutputStream to display the image in the browser this is the code:
try
{
InputStream input = Filer.readImage("images/test.jpg");
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = input.read(buffer)) != -1)
{
responseBody.write(buffer, 0, bytesRead);
}
}
catch(IOException e)
{
System.out.println(e);
}
the readImage:
public static InputStream readImage(String file) throws IOException {
InputStream input = new FileInputStream(file);
return input;
}
This is the original image:
This is the output after the above procedure:
What is wrong with my code?
You need to close the output stream:
InputStream input = Filer.readImage("images/test.jpg");
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = input.read(buffer)) != -1) {
responseBody.write(buffer, 0, bytesRead);
}
responseBody.close(); // <-----------
I know that there's a way of converting a file to byte array in chunks, here's a sample code:
InputStream inputStream = new FileInputStream(videoFile);
ByteArrayOutputStream bos = new ByteArrayOutputStream();
byte[] b = new byte[1024];
int bytesRead =0;
while ((bytesRead = inputStream.read(b)) != -1)
{
bos.write(b, 0, bytesRead);
}
I'm looking for the opposite: a way of converting a byte array into a file in chunks. I didn't find any example of doing it in chunks.
You just have to use either the write(byte[]) or write(byte[],int,int) methods from the FileOutputStream class.
byte[] to file:
FileOutputStream fop = null; File file;
try {
file = new File(filePath);
fop = new FileOutputStream(file, true);
fop.write(chunk);
fop.flush();
fop.close();
System.out.println("Done");
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
if (fop != null) {
fop.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}
Try this for file to byte[]:
InputStream is = new FileInputStream(file);
int length = (int) file.length();
int take = 262144;//size of your chunk
byte[] bytes = new byte[take];
int offset=0;
int a = 0;
do {
a = is.read(bytes, 0, take);
offset += a;
//And you can add here each chunk created in to a list, etc, etc.
//encode to base 64 this is extra :)
String str = Base64.encodeToString(bytes, Base64.DEFAULT);
} while (offset < length);=
is.close();
is=null;
Consider generalizing the problem.
This method copies data in chunks:
public static <T extends OutputStream> T copy(InputStream in, T out)
throws IOException {
byte[] buffer = new byte[1024];
for (int r = in.read(buffer); r != -1; r = in.read(buffer)) {
out.write(buffer, 0, r);
}
return out;
}
This can then be used in both reading to and from byte arrays:
try (InputStream in = new FileInputStream("original.txt");
OutputStream out = new FileOutputStream("copy.txt")) {
byte[] contents = copy(in, new ByteArrayOutputStream()).toByteArray();
copy(new ByteArrayInputStream(contents), out);
}
I have a program that updates files on the computer using information sent by a server, using sockets. The way I had it worked, but i wanted to make it more intuitive, simpler, more reliable, etc. here is the previous code:
int filesize = 6022386; // filesize temporary hardcoded
int bytesRead;
int current = 0;
/**
* receive file
*/
try {
byte[] byteArray = new byte[filesize];
java.io.InputStream inStream = socket.getInputStream();
bytesRead = inStream.read(byteArray, 0, byteArray.length);
FileOutputStream fileOutStream = new FileOutputStream(
"C:\\Program Files\\AVTECH\\NPS\\Files\\bin\\NPS Game.txt");
BufferedOutputStream buffOutStream = new BufferedOutputStream(
fileOutStream);
current = bytesRead;
do {
bytesRead = inStream.read(byteArray, current,
(byteArray.length - current));
if (bytesRead >= 0)
current += bytesRead;
} while (bytesRead > -1);
buffOutStream.write(byteArray, 0, current);
buffOutStream.flush();
buffOutStream.close();
inStream.close();
socket.close();
} catch (Exception e) {
e.printStackTrace();
socket.close();
}
as you can see, in the do, while loop, it is using the input stream to get the data. now that i've updated my program, i have the stream sending an object called UpdateObject, which holds the byte[] array along with the file directory. here is that code:
int filesize = 6022386; // filesize temporary hardcoded
int bytesRead;
int current = 0;
try {
byte[] byteArray = o.getFile();
java.io.InputStream inStream = socket.getInputStream();
bytesRead = inStream.read(byteArray, 0, byteArray.length);
FileOutputStream fileOutStream = new FileOutputStream(o.getPath());
BufferedOutputStream buffOutStream = new BufferedOutputStream(
fileOutStream);
current = bytesRead;
do {
bytesRead = inStream.read(byteArray, current,
(byteArray.length - current));
if (bytesRead >= 0)
current += bytesRead;
} while (bytesRead > -1);
buffOutStream.write(byteArray, 0, current);
buffOutStream.flush();
buffOutStream.close();
inStream.close();
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
now my question is this: how do i change it so instead of using the instream, to use just a byte[] object in the UpdateObject sent over the socket? i've done some google searching, but i dont feel like i know the right question to ask. any help would be great! thanks in advance!!!
By replacing most of your code inside the try catch block with:
FileOutputStream fileOutStream = new FileOutputStream(
UpdateObject.getDirectory()+"\\NPS Game.txt");
fileOutStream.write(UpdateObject.getBytes()); //this is the byte[] array
fileOutStream.close();
Hope this helps.