Hi Peter, Thanks for contributing to apache commons!
code snippets don't properly work in email messages, the best way to contribute code is by submitting patches, attaching them in JIRA issue - test cases are recommended! :) HTH, -Simo http://people.apache.org/~simonetripodi/ http://simonetripodi.livejournal.com/ http://twitter.com/simonetripodi http://www.99soft.org/ On Tue, Apr 9, 2013 at 2:37 PM, Peter Liu <liusz0...@gmail.com> wrote: > Hi, I'm new to Commons-IO, I wanna try a simple patch for the > issue< > https://issues.apache.org/jira/browse/IO-354?page=com.atlassian.jirafisheyeplugin:fisheye-issuepanel > >(IO-354) > which had been analyzed carefully by reporter. > > as reporter described, due to contacting the chars directly, current > implementation doesn't support multi-byte encoded String. I want to adopt > ByteArrayOutputStream , a fake stream, to solve this . that's the snippet: > ------------------------------------ > private long readLines(final RandomAccessFile reader) throws IOException { > long pos = reader.getFilePointer(); > long rePos = pos; // position to re-read > ByteArrayOutputStream lineBuf = null; > int num; > boolean seenCR = false; > try{ > lineBuf = new ByteArrayOutputStream(64); > while (getRun() && ((num = reader.read(inbuf)) != -1)) { > for (int i = 0; i < num; i++) { > final byte ch = inbuf[i]; > switch (ch) { > case '\n': > seenCR = false; // swallow CR before LF > listener.handle(new > String(lineBuf.toByteArray())); > lineBuf.reset(); > rePos = pos + i + 1; > break; > case '\r': > if (seenCR) { > lineBuf.write('\r'); > } > seenCR = true; > break; > default: > if (seenCR) { > seenCR = false; // swallow final CR > listener.handle(new > String(lineBuf.toByteArray())); > lineBuf.reset(); > rePos = pos + i + 1; > } > lineBuf.write(ch); > } > } > pos = reader.getFilePointer(); > } > }finally{ > /* > * close the stream for coding conventions and further > implementations though > * ByteArrayOutputSteram.close() is an empty method and take no > effects. > * Actually there is no more other exceptions would be threw since > adopting > * ByteArrayOutputStream, So this "finally" block is not in pair > with "catch" block. > */ > IOUtils.closeQuietly(lineBuf); > } > reader.seek(rePos); // Ensure we can re-read if necessary > return rePos; > } > ------------------------------------ > > I think, The ByteArrayOutputStream is actually an "extendable char array" > here: no more resources would be occupied except an array inside the class. > > At first I considered using a Collection to hold the bytes rather than > ByteArrayOutputStream. The Constructor of String can only support the > primitive char array ,However, the Collection can only be declared holding > Char, the Wrapper. Seem that a manual loop for converting that to primitive > is inevitable since commons-collection is not in the build path. To keep > succinct and avoid the redundant code that has been already implemented by > other basic component, I chose ByteArrayOutputStream. >
