in src/main/java/org/apache/sling/tail/impl/LogTailerWebConsolePlugin.java [74:276]
protected void renderContent(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
if(isAjaxRequest(request)) {
parseCommand(request, response);
RandomAccessFile randomAccessFile = null;
try {
try {
randomAccessFile = new RandomAccessFile(errLog, "r");
log.debug("Tailing file " + fileName + " of length " + randomAccessFile.length());
} catch (Exception e) {
log.error("Error reading " + fileName, e);
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
return;
}
JSONWriter json = new JSONWriter(response.getWriter());
json.object();
boolean reverse = false;
//long created = getCreatedTimestampFromCookie(request);
/*long modified = getModifiedTimestampFromCookie(request);
if(errLog.lastModified() == modified) {
json.endObject();
return;
}
else {
persistCookie(response, MODIFIED_COOKIE, String.valueOf(errLog.lastModified()));
}*/
long pos = getPositionFromCookie(request);
if(pos < 0) {
pos = randomAccessFile.length()-1;
reverse = true;
}
else if(pos > randomAccessFile.length()) {//file rotated
pos = 0;
}
LogFilter[] query = getQueryFromCookie(request);
if(reverse) {
randomAccessFile.seek(pos);
if(randomAccessFile.read() == '\n') {
pos--;
randomAccessFile.seek(pos);
if(randomAccessFile.read() == '\r') {
pos--;
}
}
json.key("content").array();
int found = 0;
StringBuilder sb = new StringBuilder();
String line = null;
List<String> lines = new ArrayList<String>();
while(found != LINES_TO_TAIL && pos > 0) {
boolean eol = false;
randomAccessFile.seek(pos);
int c = randomAccessFile.read();
if(c == '\n') {
found++;
sb = sb.reverse();
line = sb.toString();
sb = new StringBuilder();
eol = true;
pos--;
if(pos > 0) {
randomAccessFile.seek(pos);
if(randomAccessFile.read() == '\r') {
pos--;
}
}
}
else {
sb.append((char)c);
pos--;
}
if(eol) {
if(filter(line, query)){
lines.add(line);
}
}
}
if(pos < 0) {
if(filter(line, query)){
lines.add(line);
}
}
for(int i=lines.size()-1; i > -1; i--) {
json.object().key("line").value(lines.get(i)).endObject();
}
json.endArray();
json.endObject();
}
else {
randomAccessFile.seek(pos);
String line = null;
int lineCount = 0;
json.key("content").array();
boolean read = true;
while(read) {
StringBuilder input = new StringBuilder();
int c = -1;
boolean eol = false;
while (!eol) {
switch (c = randomAccessFile.read()) {
case -1:
case '\n':
eol = true;
break;
case '\r':
eol = true;
long cur = randomAccessFile.getFilePointer();
if ((randomAccessFile.read()) != '\n') {
randomAccessFile.seek(cur);
}
break;
default:
input.append((char)c);
break;
}
}
if ((c == -1) && (input.length() == 0)) {
read = false;
continue;
}
line = input.toString();
lineCount++;
if(lineCount == LINES_TO_TAIL) {
read = false;
}
pos = randomAccessFile.getFilePointer();
if(filter(line, query)){
json.object().key("line").value(line).endObject();
}
}
json.endArray();
json.endObject();
}
persistCookie(response, POSITION_COOKIE, String.valueOf(randomAccessFile.getFilePointer()));
} catch (Exception e) {
log.error("Error tailing " + fileName, e);
response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
}
finally {
try {
if(randomAccessFile != null) {
randomAccessFile.close();
}
}
catch (Exception e) {
log.error("Error closing " + fileName, e);
}
}
}
else {
PrintWriter printWriter = response.getWriter();
printWriter.println("<script type=\"text/javascript\" src=\"/libs/sling/logtail-plugin/js/tail.js\"></script>");
printWriter.println("<link href=\"/libs/sling/logtail-plugin/css/tail.css\" rel=\"stylesheet\" type=\"text/css\"></link>");
printWriter.println("<div class=\"header-cont\">");
printWriter.println(" <div class=\"header\" style=\"display:none;\">");
printWriter.println(" <table>");
printWriter.println(" <tr>");
printWriter.println(" <td><button class=\"numbering\" title=\"Show Line Numbers\" data-numbers=\"false\">Show Line No.</button></td>");
printWriter.println(" <td><button class=\"pause\" title=\"Pause\">Pause</button></td>");
printWriter.println(" <td class=\"longer\"><label>Sync frequency(msec)</label>");
printWriter.println(" <button class=\"faster\" title=\"Sync Faster\">-</button>");
printWriter.println(" <input id=\"speed\" type=\"text\" value=\"3000\"/>");
printWriter.println(" <button class=\"slower\" title=\"Sync Slower\">+</button></td>");
printWriter.println(" <td><button class=\"tail\" title=\"Unfollow Tail\" data-following=\"true\">Unfollow</button></td>");
printWriter.println(" <td><button class=\"highlighting\" title=\"Highlight\">Highlight</button></td>");
printWriter.println(" <td><button class=\"clear\" title=\"Clear Display\">Clear</button></td>");
printWriter.println(" <td class=\"longer\"><input id=\"filter\" type=\"text\"/><span class=\"filterClear ui-icon ui-icon-close\" title=\"Clear Filter\"> </span><button class=\"filter\" title=\"Filter Logs\">Filter</button></td>");
printWriter.println(" <td><button class=\"refresh\" title=\"Reload Logs\">Reload</button></td>");
printWriter.println(" <td><button class=\"sizeplus\" title=\"Bigger\">a->A</button></td>");
printWriter.println(" <td><button class=\"sizeminus\" title=\"Smaller\">A->a</button></td>");
printWriter.println(" <td><button class=\"top\" title=\"Scroll to Top\">Top</button></td>");
printWriter.println(" <td><button class=\"bottom\" title=\"Scroll to Bottom\">Bottom</button></td>");
printWriter.println(" </tr>");
printWriter.println(" <tr>");
printWriter.println(" <td class=\"loadingstatus\" colspan=\"2\" data-status=\"inactive\"><ul><li></li></ul></td>");
printWriter.println(" <td>Tailing <select id=\"logfiles\">" + getOptions() + "</select></td>");
printWriter.println(" </tr>");
printWriter.println(" </table>");
printWriter.println(" </div>");
printWriter.println(" <div class=\"pulldown\" title=\"Click to show options\"> == </div>");
printWriter.println("</div>");
printWriter.println("");
printWriter.println(" <div class=\"content\">");
printWriter.println("");
printWriter.println(" <div id=\"logarea\"></div>");
printWriter.println("");
printWriter.println(" </div>");
}
}