What's the best way to check if a Reader is empty?
I need to detect if a Reader is empty (will yield no data), before I pass the reader to some external function.
The best I can come up with is to wrap my Reader in a BufferedReader which guarantees to provide mark/reset functionality, and then attempt to read a single character before resetting the stream to its original position.
BufferedReader buffered = new BufferedReader(myReader);
if (!isEmpty(buffered)) {
someOtherFunction(buffered);
}
private boolean isEmpty(BufferedReader reader) throws IOException {
reader.mark(1);
int c = reader.read();
reader.reset();
return c < 0;
}
Is there a better way?
java bufferedreader is-empty
asked Nov 20 at 21:53
Graham Borland
48.4k16116162
add a comment |
I need to detect if a Reader is empty (will yield no data), before I pass the reader to some external function.
The best I can come up with is to wrap my Reader in a BufferedReader which guarantees to provide mark/reset functionality, and then attempt to read a single character before resetting the stream to its original position.
BufferedReader buffered = new BufferedReader(myReader);
if (!isEmpty(buffered)) {
someOtherFunction(buffered);
}
private boolean isEmpty(BufferedReader reader) throws IOException {
reader.mark(1);
int c = reader.read();
reader.reset();
return c < 0;
}
Is there a better way?
java bufferedreader is-empty
asked Nov 20 at 21:53
Graham Borland
48.4k16116162
add a comment |
I need to detect if a Reader is empty (will yield no data), before I pass the reader to some external function.
The best I can come up with is to wrap my Reader in a BufferedReader which guarantees to provide mark/reset functionality, and then attempt to read a single character before resetting the stream to its original position.
BufferedReader buffered = new BufferedReader(myReader);
if (!isEmpty(buffered)) {
someOtherFunction(buffered);
}
private boolean isEmpty(BufferedReader reader) throws IOException {
reader.mark(1);
int c = reader.read();
reader.reset();
return c < 0;
}
Is there a better way?
java bufferedreader is-empty
asked Nov 20 at 21:53
Graham Borland
48.4k16116162
I need to detect if a Reader is empty (will yield no data), before I pass the reader to some external function.
The best I can come up with is to wrap my Reader in a BufferedReader which guarantees to provide mark/reset functionality, and then attempt to read a single character before resetting the stream to its original position.
BufferedReader buffered = new BufferedReader(myReader);
if (!isEmpty(buffered)) {
someOtherFunction(buffered);
}
private boolean isEmpty(BufferedReader reader) throws IOException {
reader.mark(1);
int c = reader.read();
reader.reset();
return c < 0;
}
Is there a better way?
java bufferedreader is-empty
java bufferedreader is-empty
asked Nov 20 at 21:53
Graham Borland
48.4k16116162
asked Nov 20 at 21:53
Graham Borland
48.4k16116162
asked Nov 20 at 21:53
Graham Borland
48.4k16116162
asked Nov 20 at 21:53
Graham Borland
48.4k16116162
asked Nov 20 at 21:53
Graham Borland
48.4k16116162
48.4k16116162
add a comment |
add a comment |
1 Answer
1
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Use ready() to check stream is available to read or not here docs
And also recommended null check before checking ready()
public boolean ready() throws IOException
Tells whether this stream is ready to be read. A buffered character stream is ready if the buffer is not empty, or if the underlying character stream is ready.
Note :
True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.
answered Nov 20 at 22:04
Deadpool
3,5692324
add a comment |
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1 Answer
1
active
oldest
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1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
Use ready() to check stream is available to read or not here docs
And also recommended null check before checking ready()
public boolean ready() throws IOException
Tells whether this stream is ready to be read. A buffered character stream is ready if the buffer is not empty, or if the underlying character stream is ready.
Note :
True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.
answered Nov 20 at 22:04
Deadpool
3,5692324
add a comment |
Use ready() to check stream is available to read or not here docs
And also recommended null check before checking ready()
public boolean ready() throws IOException
Tells whether this stream is ready to be read. A buffered character stream is ready if the buffer is not empty, or if the underlying character stream is ready.
Note :
True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.
answered Nov 20 at 22:04
Deadpool
3,5692324
add a comment |
Use ready() to check stream is available to read or not here docs
And also recommended null check before checking ready()
public boolean ready() throws IOException
Tells whether this stream is ready to be read. A buffered character stream is ready if the buffer is not empty, or if the underlying character stream is ready.
Note :
True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.
answered Nov 20 at 22:04
Deadpool
3,5692324
Use ready() to check stream is available to read or not here docs
And also recommended null check before checking ready()
public boolean ready() throws IOException
Tells whether this stream is ready to be read. A buffered character stream is ready if the buffer is not empty, or if the underlying character stream is ready.
Note :
True if the next read() is guaranteed not to block for input, false otherwise. Note that returning false does not guarantee that the next read will block.
answered Nov 20 at 22:04
Deadpool
3,5692324
edited Nov 20 at 22:16
answered Nov 20 at 22:04
Deadpool
3,5692324
answered Nov 20 at 22:04
Deadpool
3,5692324
answered Nov 20 at 22:04
Deadpool
3,5692324
3,5692324
add a comment |
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