i need some help with writing a parser.
this is the format of a log entry:
yyyy-MM-dd HH:mm:ss,SSS | level | emiter | user name | user | class name | method name | message
and this is the code of my parser:
Code: Select all
private ParsedEntry entry = null;
private final static SimpleDateFormat DATE_FORMAT = new SimpleDateFormat(
"yyyy-MM-dd HH:mm:ss,SSS");
private final static Pattern ENTRY_BEGIN_PATTERN = Pattern
.compile("^\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2},\\d{3}.*$");
private StringBuilder entryMsgBuffer = null;
/** Key of user-defined fields */
private static final String USER_NAME = "User Name";
private static final String USER = "User";
private static final String CALLING_CLASS = "Calling Class";
private static final String CALLING_METHOD = "Calling Method";
private static final List<String> EXTRA_FIELDS_KEYS = Arrays
.asList(USER_NAME, USER, CALLING_CLASS, CALLING_METHOD);
protected void parseLine(String line) throws Exception {
//yyyy-MM-dd HH:mm:ss,SSS | level | emiter | user name | user | class name | method name | message
// If end of file, records last entry if necessary, and exits
if (line == null) {
recordPreviousEntryIfExists();
return;
}
String trimmedLine = line;//.replaceAll("\\s+", "");
Matcher matcher = ENTRY_BEGIN_PATTERN.matcher(trimmedLine);
if (matcher.matches()) {
// Record previous found entry if exists, then create a new one
prepareNewEntry();
String[] fields = trimmedLine.split("\\|");
entry.setDate(fields[0].trim());
entry.setLevel(fields[1].trim());
entry.setEmitter(fields[2].trim());
entryMsgBuffer.append(fields[7].trim());
entry.getUserDefinedFields().put(USER_NAME, fields[3].trim());
entry.getUserDefinedFields().put(USER, fields[4].trim());
entry.getUserDefinedFields().put(CALLING_CLASS, fields[5].trim());
entry.getUserDefinedFields().put(CALLING_METHOD, fields[6].trim());
} else if (entry != null) {
entryMsgBuffer.append('\n').append(trimmedLine); // appends this line to previous entry's text
}
}
public List<String> getUserDefinedFields() {
return EXTRA_FIELDS_KEYS;
}
public Date getRelativeEntryDate(ParsedEntry pEntry) throws Exception {
return DATE_FORMAT.parse(pEntry.getDate());
}
public Date getAbsoluteEntryDate(ParsedEntry pEntry) throws Exception {
return DATE_FORMAT.parse(pEntry.getDate());
}
private void recordPreviousEntryIfExists() throws Exception {
if (entry != null) {
entry.setMessage(entryMsgBuffer.toString());
addEntry(entry);
}
}
private void prepareNewEntry() throws Exception {
recordPreviousEntryIfExists();
entry = createNewEntry();
entryMsgBuffer = new StringBuilder(80);
entry.setUserDefinedFields(new HashMap<String, Object>(1)); // Create an empty Map with only one element allocated
}BUT!!
sometimes my log entry starts with some empty space at the beginning of a line (i cannot control this).
this is where it is all getting messy.
i tried line = line.trim() ... tried .replaceAll("\\s+", ""); but i only getting errors from LOGMX.
plz help with a solution.
, just replace