stoerr · October 8, 2019 14:09
diff --git a/threaddump.jsp b/threaddump.jsp
 <%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 <%--
    This JSP lists all threads with stati as configured in a checklist, optionally whose names match a specified regex.
    If two threads have the same stacktrace, they are shown together and the stacktrace is printed only once.
 --%>
 <%@page import="java.util.*"%>
 <%@page import="javax.servlet.*"%>
 <%@page import="java.io.*"%>
 <%@page import="java.util.regex.*"%>
 <%@page import="java.util.stream.Collectors"%>
 <%@page import="org.apache.commons.lang3.tuple.Pair"%>
 <%@page import="org.apache.commons.lang3.StringUtils"%>
 <%

    final String PARAM_STATE = "state";
    final String PARAM_NAMEREGEX = "nameregex";

    class ThreaddumpRunner {
        protected final JspWriter writer;
        protected final HttpServletRequest request;
        protected Set<Thread.State> stati = Collections.singleton(Thread.State.RUNNABLE);
        protected String nameRegexStr = "";
        protected Pattern nameRegex = Pattern.compile(nameRegexStr);

        public ThreaddumpRunner(JspWriter writer, HttpServletRequest request) throws Exception {
            this.writer = writer;
            this.request = request;

            String[] statiArray = request.getParameterValues(PARAM_STATE);
            if (statiArray != null && statiArray.length > 0) {
                stati = new HashSet<>();
                for (String stateStr : statiArray) {
                    Thread.State state = Thread.State.valueOf(stateStr);
                    stati.add(state);
                }
            }

            if (StringUtils.isNotBlank(request.getParameter(PARAM_NAMEREGEX))) {
                nameRegexStr = request.getParameter(PARAM_NAMEREGEX);
                try {
                    nameRegex = Pattern.compile(nameRegexStr);
                } catch (PatternSyntaxException e) {
                    writer.println("<p><strong>Regex syntax error: " + e + "</strong></p>");
                }
            }
        }

        public void print() throws Exception {
            printForm();
            writer.println("<p>Since many threads share the same stacktrace, threads with the " +
                    "same stacktrace are grouped together.</p><br>");
            printThreads();
        }

        protected void printThreads() throws Exception {
            writer.println("<ul>");
            Map<Thread, StackTraceElement[]> traceMap = Thread.getAllStackTraces();

            List<Pair<Thread, String>> traces = traceMap.entrySet().stream()
                    .map((e) -> Pair.of(e.getKey(), stackTrace(e.getValue())))
                    .filter((e) -> nameRegex.matcher(e.getLeft().getName()).find())
                    .filter((e) -> stati.contains(e.getLeft().getState()))
                    .collect(Collectors.toList());
            Collections.sort(traces, Comparator.comparing((e) -> e.getLeft().getName()));

            // Since many many traces have the same stacktrace, we group them by stacktrace.
            Map<String, List<Pair<Thread, String>>> tracesGrouped = new TreeMap<>(traces.stream()
                    .collect(Collectors.groupingBy((e) -> e.getRight())));
            List<Pair<String, List<Thread>>> tracesGroupedByStacktrace = tracesGrouped.entrySet().stream()
                    .map(e -> Pair.of(e.getKey(), extractThreads(e.getValue())))
                    .collect(Collectors.toList());
            Collections.sort(tracesGroupedByStacktrace, Comparator.comparing((e) -> e.getRight().get(0).getName()));

            for (Pair<String, List<Thread>> traceAndThreads : tracesGroupedByStacktrace) {
                writer.println("<li>");
                for (Thread t : traceAndThreads.getRight()) {
                    writer.print(t.getId());
                    writer.print(" (" + t.getState() + ")");
                    writer.print(" : ");
                    writer.print(t.getName());
                    writer.println("<br/>");
                }
                writer.println("<pre>");
                writer.println(traceAndThreads.getLeft());
                writer.println("</pre>");
                writer.println("</li>");
            }

            writer.println("</ul>");
        }

        private List<Thread> extractThreads(List<Pair<Thread, String>> threadTraces) {
            return threadTraces.stream()
                    .map((e) -> e.getLeft())
                    .collect(Collectors.toList());
        }

        protected String stackTrace(StackTraceElement[] stackTraceElements) {
            StringBuffer buf = new StringBuffer();
            for (StackTraceElement stackTraceElement : stackTraceElements) {
                buf.append("     at ")
                        .append(stackTraceElement)
                        .append("\n");
            }
            return buf.toString();
        }

        protected void printForm() throws Exception {
            writer.println("<form action=\"" + request.getRequestURL() + "\" method=\"get\">");
            writer.println("Print only threads of stati ");
            for (Thread.State value : Thread.State.values()) {
                String checked = stati.contains(value) ? "checked" : "";
                writer.println("  <input type=\"checkbox\" name=\"state\" value=\"" + value.name() + "\" "
                        + checked + "> " + value);
            }
            writer.println(" with names matching regex <input type=\"text\" name=\"nameregex\" value=\"" + nameRegex + "\">");
            writer.println(" <input type=\"submit\">\n");
            writer.println("</form>");
        }

    }

        out.println("<html><body><h2>Thread dump</h2>");
        new ThreaddumpRunner(out, request).print();
        out.println("</body></html>");


 %>
	<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
	pageEncoding="ISO-8859-1"%>
	<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
	<%--
	This JSP lists all threads with stati as configured in a checklist, optionally whose names match a specified regex.
	If two threads have the same stacktrace, they are shown together and the stacktrace is printed only once.
	--%>
	<%@page import="java.util.*"%>
	<%@page import="javax.servlet.*"%>
	<%@page import="java.io.*"%>
	<%@page import="java.util.regex.*"%>
	<%@page import="java.util.stream.Collectors"%>
	<%@page import="org.apache.commons.lang3.tuple.Pair"%>
	<%@page import="org.apache.commons.lang3.StringUtils"%>
	<%

	final String PARAM_STATE = "state";
	final String PARAM_NAMEREGEX = "nameregex";

	class ThreaddumpRunner {
	protected final JspWriter writer;
	protected final HttpServletRequest request;
	protected Set<Thread.State> stati = Collections.singleton(Thread.State.RUNNABLE);
	protected String nameRegexStr = "";
	protected Pattern nameRegex = Pattern.compile(nameRegexStr);

	public ThreaddumpRunner(JspWriter writer, HttpServletRequest request) throws Exception {
	this.writer = writer;
	this.request = request;

	String[] statiArray = request.getParameterValues(PARAM_STATE);
	if (statiArray != null && statiArray.length > 0) {
	stati = new HashSet<>();
	for (String stateStr : statiArray) {
	Thread.State state = Thread.State.valueOf(stateStr);
	stati.add(state);
	}
	}

	if (StringUtils.isNotBlank(request.getParameter(PARAM_NAMEREGEX))) {
	nameRegexStr = request.getParameter(PARAM_NAMEREGEX);
	try {
	nameRegex = Pattern.compile(nameRegexStr);
	} catch (PatternSyntaxException e) {
	writer.println("<p><strong>Regex syntax error: " + e + "</strong></p>");
	}
	}
	}

	public void print() throws Exception {
	printForm();
	writer.println("<p>Since many threads share the same stacktrace, threads with the " +
	"same stacktrace are grouped together.</p><br>");
	printThreads();
	}

	protected void printThreads() throws Exception {
	writer.println("<ul>");
	Map<Thread, StackTraceElement[]> traceMap = Thread.getAllStackTraces();

	List<Pair<Thread, String>> traces = traceMap.entrySet().stream()
	.map((e) -> Pair.of(e.getKey(), stackTrace(e.getValue())))
	.filter((e) -> nameRegex.matcher(e.getLeft().getName()).find())
	.filter((e) -> stati.contains(e.getLeft().getState()))
	.collect(Collectors.toList());
	Collections.sort(traces, Comparator.comparing((e) -> e.getLeft().getName()));

	// Since many many traces have the same stacktrace, we group them by stacktrace.
	Map<String, List<Pair<Thread, String>>> tracesGrouped = new TreeMap<>(traces.stream()
	.collect(Collectors.groupingBy((e) -> e.getRight())));
	List<Pair<String, List<Thread>>> tracesGroupedByStacktrace = tracesGrouped.entrySet().stream()
	.map(e -> Pair.of(e.getKey(), extractThreads(e.getValue())))
	.collect(Collectors.toList());
	Collections.sort(tracesGroupedByStacktrace, Comparator.comparing((e) -> e.getRight().get(0).getName()));

	for (Pair<String, List<Thread>> traceAndThreads : tracesGroupedByStacktrace) {
	writer.println("<li>");
	for (Thread t : traceAndThreads.getRight()) {
	writer.print(t.getId());
	writer.print(" (" + t.getState() + ")");
	writer.print(" : ");
	writer.print(t.getName());
	writer.println("<br/>");
	}
	writer.println("<pre>");
	writer.println(traceAndThreads.getLeft());
	writer.println("</pre>");
	writer.println("</li>");
	}

	writer.println("</ul>");
	}

	private List<Thread> extractThreads(List<Pair<Thread, String>> threadTraces) {
	return threadTraces.stream()
	.map((e) -> e.getLeft())
	.collect(Collectors.toList());
	}

	protected String stackTrace(StackTraceElement[] stackTraceElements) {
	StringBuffer buf = new StringBuffer();
	for (StackTraceElement stackTraceElement : stackTraceElements) {
	buf.append(" at ")
	.append(stackTraceElement)
	.append("\n");
	}
	return buf.toString();
	}

	protected void printForm() throws Exception {
	writer.println("<form action=\"" + request.getRequestURL() + "\" method=\"get\">");
	writer.println("Print only threads of stati ");
	for (Thread.State value : Thread.State.values()) {
	String checked = stati.contains(value) ? "checked" : "";
	writer.println(" <input type=\"checkbox\" name=\"state\" value=\"" + value.name() + "\" "
	+ checked + "> " + value);
	}
	writer.println(" with names matching regex <input type=\"text\" name=\"nameregex\" value=\"" + nameRegex + "\">");
	writer.println(" <input type=\"submit\">\n");
	writer.println("</form>");
	}

	}

	out.println("<html><body><h2>Thread dump</h2>");
	new ThreaddumpRunner(out, request).print();
	out.println("</body></html>");


	%>