Posted By

narkisr on 01/31/08


Tagged

java tail Assertion


Versions (?)

Who likes this?

1 person have marked this snippet as a favorite

zuoky


Simple tail like assertion


 / Published in: Java
 

A simple testing assertion which looks up for a line within a file until a pre defined time frame ends (loosely based upon http://www.informit.com/guides/content.aspx?g=java&seqNum=226).

  1. public class TailAssertor {
  2.  
  3. private static final long sec = 1000L;
  4.  
  5. private static final Log log = LogService.getLog(TailAssertor.class.getName());
  6.  
  7. private static long sampleInterval = 5000;
  8.  
  9. public static void assertNewLinesWithTail(final File logfile, final String expectedLine, int durationInSec) {
  10.  
  11. long filePointer = logfile.length();// The file pointer keeps track of where we are in the file
  12. RandomAccessFile file = null;
  13. try {
  14. file = new RandomAccessFile(logfile, "r");
  15. for (final Date startTime = new Date(); new Date().getTime() - startTime.getTime() < durationInSec * sec;) {
  16. long fileLength = logfile.length();
  17. if (fileLength < filePointer) {// file has been cleared
  18. file = new RandomAccessFile(logfile, "r");
  19. filePointer = 0;
  20. }
  21. if (fileLength > filePointer) {
  22. file.seek(filePointer);// There is new data to read
  23. for (String line = file.readLine(); line != null;) {
  24. if (line.contains(expectedLine)) {
  25. return;
  26. }
  27. line = file.readLine();
  28. }
  29. filePointer = file.getFilePointer();
  30. }
  31. Thread.sleep(sampleInterval);// Sleep for the specified interval
  32. }
  33. } catch (Exception e) {
  34. log.error(e);
  35. } finally {
  36. closeFile(file);
  37. }
  38. throw new AssertionError("the requested line wasn't found within the required time frame!");
  39. }
  40.  
  41. private static void closeFile(RandomAccessFile file) {
  42. if (file != null) {
  43. try {
  44. file.close();
  45. } catch (IOException e) {
  46. log.error(e);
  47. }
  48. }
  49. }
  50. }

Report this snippet  

Comments

RSS Icon Subscribe to comments
Posted By: zuoky on January 21, 2009

Pretty good, want to do a log tailer then.

Posted By: narkisr on January 25, 2009

Cool, happy that youv found it useful.

You need to login to post a comment.