private boolean openWriter() {
if (printWriter == null) {
try {
FileUtils.createDirectories(FileUtils.getParent(fileName));
if (FileUtils.exists(fileName) && !FileUtils.canWrite(fileName)) {
// read only database: don't log error if the trace file
// can't be opened
return false;
}
fileWriter = IOUtils.getBufferedWriter(FileUtils.newOutputStream(fileName, true));
printWriter = new PrintWriter(fileWriter, true);
} catch (Exception e) {
logWritingError(e);
return false;
}
}
return true;
}
/**
* Get a writer to update the Clob. This is only supported for new, empty Clob objects that were
* created with Connection.createClob() or createNClob(). The Clob is created in a separate
* thread, and the object is only updated when Writer.close() is called. The position must be 1,
* meaning the whole Clob data is set.
*
* @param pos where to start writing (the first character is at position 1)
* @return a writer
*/
public Writer setCharacterStream(long pos) throws SQLException {
try {
if (isDebugEnabled()) {
debugCodeCall("setCharacterStream(" + pos + ");");
}
checkClosed();
if (pos != 1) {
throw DbException.getInvalidValueException("pos", pos);
}
if (value.getPrecision() != 0) {
throw DbException.getInvalidValueException("length", value.getPrecision());
}
final JdbcConnection c = conn;
// PipedReader / PipedWriter are a lot slower
// than PipedInputStream / PipedOutputStream
// (Sun/Oracle Java 1.6.0_20)
final PipedInputStream in = new PipedInputStream();
final Task task =
new Task() {
public void call() {
value = c.createClob(IOUtils.getReader(in), -1);
}
};
PipedOutputStream out =
new PipedOutputStream(in) {
public void close() throws IOException {
super.close();
try {
task.get();
} catch (Exception e) {
throw DbException.convertToIOException(e);
}
}
};
task.execute();
return IOUtils.getBufferedWriter(out);
} catch (Exception e) {
throw logAndConvert(e);
}
}
