Shouldn't we keep track of the offset when we write to an OutputStream?
The read() method inside copyFile() reads buf.length bytes from the input stream and then it writes them to the output stream from the start until len.
public static boolean copyFile(InputStream inputStream, OutputStream out) {
byte buf = new byte[1024];
int len;
try {
while ((len = inputStream.read(buf)) != -1) {
out.write(buf, 0, len);
}
out.close();
inputStream.close();
} catch (IOException e) {
return false;
}
return true;
}
If we always writing to the output stream from the start isn't the data of the previous iteration overwritten?
Don't we need to keep track of the offset? For example if the first iteration wrote 1024 bytes then the second iteration should write out.write(buf,1024,len);.
java io inputstream outputstream
edited Nov 22 '18 at 13:02
Micha Wiedenmann
10.4k1364104
asked Nov 22 '18 at 13:00
SkemelioSkemelio
683515
add a comment |
The read() method inside copyFile() reads buf.length bytes from the input stream and then it writes them to the output stream from the start until len.
public static boolean copyFile(InputStream inputStream, OutputStream out) {
byte buf = new byte[1024];
int len;
try {
while ((len = inputStream.read(buf)) != -1) {
out.write(buf, 0, len);
}
out.close();
inputStream.close();
} catch (IOException e) {
return false;
}
return true;
}
If we always writing to the output stream from the start isn't the data of the previous iteration overwritten?
Don't we need to keep track of the offset? For example if the first iteration wrote 1024 bytes then the second iteration should write out.write(buf,1024,len);.
java io inputstream outputstream
edited Nov 22 '18 at 13:02
Micha Wiedenmann
10.4k1364104
asked Nov 22 '18 at 13:00
SkemelioSkemelio
683515
2
The start is the start of the array, not of the stream. The data is in fact appended to the previous one each time.
– Arnaud
Nov 22 '18 at 13:09
Thanks @Arnaud!
– Skemelio
Nov 22 '18 at 13:10
add a comment |
The read() method inside copyFile() reads buf.length bytes from the input stream and then it writes them to the output stream from the start until len.
public static boolean copyFile(InputStream inputStream, OutputStream out) {
byte buf = new byte[1024];
int len;
try {
while ((len = inputStream.read(buf)) != -1) {
out.write(buf, 0, len);
}
out.close();
inputStream.close();
} catch (IOException e) {
return false;
}
return true;
}
If we always writing to the output stream from the start isn't the data of the previous iteration overwritten?
Don't we need to keep track of the offset? For example if the first iteration wrote 1024 bytes then the second iteration should write out.write(buf,1024,len);.
java io inputstream outputstream
edited Nov 22 '18 at 13:02
Micha Wiedenmann
10.4k1364104
asked Nov 22 '18 at 13:00
SkemelioSkemelio
683515
The read() method inside copyFile() reads buf.length bytes from the input stream and then it writes them to the output stream from the start until len.
public static boolean copyFile(InputStream inputStream, OutputStream out) {
byte buf = new byte[1024];
int len;
try {
while ((len = inputStream.read(buf)) != -1) {
out.write(buf, 0, len);
}
out.close();
inputStream.close();
} catch (IOException e) {
return false;
}
return true;
}
If we always writing to the output stream from the start isn't the data of the previous iteration overwritten?
Don't we need to keep track of the offset? For example if the first iteration wrote 1024 bytes then the second iteration should write out.write(buf,1024,len);.
java io inputstream outputstream
java io inputstream outputstream
edited Nov 22 '18 at 13:02
Micha Wiedenmann
10.4k1364104
asked Nov 22 '18 at 13:00
SkemelioSkemelio
683515
edited Nov 22 '18 at 13:02
Micha Wiedenmann
10.4k1364104
asked Nov 22 '18 at 13:00
SkemelioSkemelio
683515
edited Nov 22 '18 at 13:02
Micha Wiedenmann
10.4k1364104
edited Nov 22 '18 at 13:02
Micha Wiedenmann
10.4k1364104
edited Nov 22 '18 at 13:02
Micha Wiedenmann
10.4k1364104
10.4k1364104
asked Nov 22 '18 at 13:00
SkemelioSkemelio
683515
asked Nov 22 '18 at 13:00
SkemelioSkemelio
683515
asked Nov 22 '18 at 13:00
SkemelioSkemelio
683515
683515
2
The start is the start of the array, not of the stream. The data is in fact appended to the previous one each time.
– Arnaud
Nov 22 '18 at 13:09
Thanks @Arnaud!
– Skemelio
Nov 22 '18 at 13:10
add a comment |
2
The start is the start of the array, not of the stream. The data is in fact appended to the previous one each time.
– Arnaud
Nov 22 '18 at 13:09
Thanks @Arnaud!
– Skemelio
Nov 22 '18 at 13:10
2
2
The start is the start of the array, not of the stream. The data is in fact appended to the previous one each time.
– Arnaud
Nov 22 '18 at 13:09
The start is the start of the array, not of the stream. The data is in fact appended to the previous one each time.
– Arnaud
Nov 22 '18 at 13:09
Thanks @Arnaud!
– Skemelio
Nov 22 '18 at 13:10
Thanks @Arnaud!
– Skemelio
Nov 22 '18 at 13:10
add a comment |
2 Answers
2
active
oldest
votes
The fact is that the buf is a buffer and not the entire data stream.
Also, you are using public int read(byte b) method which means which it is same as read(b, 0, b.length). So the buffer shall be pointing to next buf.length values of the data.
For more information, please check https://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#read(byte) .
answered Nov 22 '18 at 13:12
CS_noobCS_noob
4551311
Thanks for your answer. My query was about write() but it's ok it's being answered in the comments.
– Skemelio
Nov 22 '18 at 13:14
add a comment |
As @Arnaud commented
The start is the start of the array, not of the stream. The data is in
fact appended to the previous one each time.
I was not careful quick scanning the docs and from "Writes len bytes from the specified byte array starting at offset off to this output stream", I got the point that off was the offset of the stream.
answered Nov 22 '18 at 13:19
SkemelioSkemelio
683515
add a comment |
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2 Answers
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2 Answers
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The fact is that the buf is a buffer and not the entire data stream.
Also, you are using public int read(byte b) method which means which it is same as read(b, 0, b.length). So the buffer shall be pointing to next buf.length values of the data.
For more information, please check https://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#read(byte) .
answered Nov 22 '18 at 13:12
CS_noobCS_noob
4551311
Thanks for your answer. My query was about write() but it's ok it's being answered in the comments.
– Skemelio
Nov 22 '18 at 13:14
add a comment |
The fact is that the buf is a buffer and not the entire data stream.
Also, you are using public int read(byte b) method which means which it is same as read(b, 0, b.length). So the buffer shall be pointing to next buf.length values of the data.
For more information, please check https://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#read(byte) .
answered Nov 22 '18 at 13:12
CS_noobCS_noob
4551311
Thanks for your answer. My query was about write() but it's ok it's being answered in the comments.
– Skemelio
Nov 22 '18 at 13:14
add a comment |
The fact is that the buf is a buffer and not the entire data stream.
Also, you are using public int read(byte b) method which means which it is same as read(b, 0, b.length). So the buffer shall be pointing to next buf.length values of the data.
For more information, please check https://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#read(byte) .
answered Nov 22 '18 at 13:12
CS_noobCS_noob
4551311
The fact is that the buf is a buffer and not the entire data stream.
Also, you are using public int read(byte b) method which means which it is same as read(b, 0, b.length). So the buffer shall be pointing to next buf.length values of the data.
For more information, please check https://docs.oracle.com/javase/7/docs/api/java/io/InputStream.html#read(byte) .
answered Nov 22 '18 at 13:12
CS_noobCS_noob
4551311
answered Nov 22 '18 at 13:12
CS_noobCS_noob
4551311
answered Nov 22 '18 at 13:12
CS_noobCS_noob
4551311
answered Nov 22 '18 at 13:12
CS_noobCS_noob
4551311
4551311
Thanks for your answer. My query was about write() but it's ok it's being answered in the comments.
– Skemelio
Nov 22 '18 at 13:14
add a comment |
Thanks for your answer. My query was about write() but it's ok it's being answered in the comments.
– Skemelio
Nov 22 '18 at 13:14
Thanks for your answer. My query was about write() but it's ok it's being answered in the comments.
– Skemelio
Nov 22 '18 at 13:14
Thanks for your answer. My query was about write() but it's ok it's being answered in the comments.
– Skemelio
Nov 22 '18 at 13:14
add a comment |
As @Arnaud commented
The start is the start of the array, not of the stream. The data is in
fact appended to the previous one each time.
I was not careful quick scanning the docs and from "Writes len bytes from the specified byte array starting at offset off to this output stream", I got the point that off was the offset of the stream.
answered Nov 22 '18 at 13:19
SkemelioSkemelio
683515
add a comment |
As @Arnaud commented
The start is the start of the array, not of the stream. The data is in
fact appended to the previous one each time.
I was not careful quick scanning the docs and from "Writes len bytes from the specified byte array starting at offset off to this output stream", I got the point that off was the offset of the stream.
answered Nov 22 '18 at 13:19
SkemelioSkemelio
683515
add a comment |
As @Arnaud commented
The start is the start of the array, not of the stream. The data is in
fact appended to the previous one each time.
I was not careful quick scanning the docs and from "Writes len bytes from the specified byte array starting at offset off to this output stream", I got the point that off was the offset of the stream.
answered Nov 22 '18 at 13:19
SkemelioSkemelio
683515
As @Arnaud commented
The start is the start of the array, not of the stream. The data is in
fact appended to the previous one each time.
I was not careful quick scanning the docs and from "Writes len bytes from the specified byte array starting at offset off to this output stream", I got the point that off was the offset of the stream.
answered Nov 22 '18 at 13:19
SkemelioSkemelio
683515
edited Nov 22 '18 at 13:28
answered Nov 22 '18 at 13:19
SkemelioSkemelio
683515
answered Nov 22 '18 at 13:19
SkemelioSkemelio
683515
answered Nov 22 '18 at 13:19
SkemelioSkemelio
683515
683515
add a comment |
add a comment |
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2
The start is the start of the array, not of the stream. The data is in fact appended to the previous one each time.
– Arnaud
Nov 22 '18 at 13:09
Thanks @Arnaud!
– Skemelio
Nov 22 '18 at 13:10