private List<Action<T>> handlers;

    @Override
    public void onValueChange(Action<T> action) {
        if (handlers == null) {
            handlers = new ArrayList<>();
        }
        handlers.add(action);
    }

    public void handle(T previousValue) {
        if (handlers != null) {
            for (Action<T> handler : handlers) {
                handler.execute(previousValue);
            }

	// Check that the Go code saw SIGIO.
	awaitSIGIO = (void (*)(void))dlsym(handle, "AwaitSIGIO");
	if (awaitSIGIO == NULL) {
		fprintf(stderr, "%s\n", dlerror());
		exit(EXIT_FAILURE);
	}

	if (verbose) {
		fprintf(stderr, "calling AwaitSIGIO\n");
	}

	awaitSIGIO();

	if (sigioSeen != 0) {
		fprintf(stderr, "C handler saw SIGIO when only Go handler should have\n");
		exit(EXIT_FAILURE);
	}

	*p = '\0';
	if (i > 0) {
		recur(i - 1, a);
	}
}

// Signal handler that uses up more stack space than a goroutine will have.
static void ioHandler(int signo, siginfo_t* info, void* ctxt) {
	char a[1024];

	recur(4, a);
	sigioSeen = 1;
}

static jmp_buf jmp;
static char* nullPointer;

// Signal handler for SIGSEGV on a C thread.
static void segvHandler(int signo, siginfo_t* info, void* ctxt) {

import org.dbflute.utflute.core.PlainTestCase;
import org.mortbay.jetty.Handler;
import org.mortbay.jetty.HttpConnection;
import org.mortbay.jetty.HttpMethods;
import org.mortbay.jetty.Server;
import org.mortbay.jetty.handler.AbstractHandler;
import org.mortbay.jetty.handler.DefaultHandler;
import org.mortbay.jetty.handler.HandlerList;

/**
 * @author shinsuke
 *
 */

	*p = '\0';
	if (i > 0) {
		recur(i - 1, a);
	}
}

static void pipeHandler(int signo, siginfo_t* info, void* ctxt) {
	sigpipeSeen = 1;
}

// Signal handler that uses up more stack space than a goroutine will have.
static void ioHandler(int signo, siginfo_t* info, void* ctxt) {
	char a[1024];

	recur(4, a);
	sigioSeen = 1;
}

static jmp_buf jmp;
static char* nullPointer;

#include "libgo4.h"

#ifdef _AIX
// On AIX, CSIGSTKSZ is too small to handle Go sighandler.
#define CSIGSTKSZ 0x4000
#else
#define CSIGSTKSZ SIGSTKSZ
#endif

static void die(const char* msg) {
	perror(msg);
	exit(EXIT_FAILURE);
}

static int ok = 1;

static void ioHandler(int signo, siginfo_t* info, void* ctxt) {
}

// Set up the SIGIO signal handler in a high priority constructor, so

}

func scriptHandle() script.Cmd {
	return script.Command(
		script.CmdUsage{
			Summary: "set the HTTP handler that will serve the script's output",
			Args:    "handler [dir]",
			Detail: []string{
				"The handler will be passed the script's current working directory and environment as arguments.",
				"Valid handlers include 'dir' (for general http.Dir serving), 'bzr', 'fossil', 'git', and 'hg'",
			},
		},

    }

    @Override
    public void addHandlers(Map<String, ArtifactHandler> handlers) {
        throw new UnsupportedOperationException("Adding handlers programmatically is not supported anymore");
    }

    @Deprecated
    public Set<String> getHandlerTypes() {
        throw new UnsupportedOperationException("Querying handlers programmatically is not supported anymore");
    }

	"slices"
	"strings"
	"sync"
	"time"
)

type hgHandler struct {
	once      sync.Once
	hgPath    string
	hgPathErr error
}

func (h *hgHandler) Available() bool {
	h.once.Do(func() {
		h.hgPath, h.hgPathErr = exec.LookPath("hg")
	})
	return h.hgPathErr == nil
}

func (h *hgHandler) Handler(dir string, env []string, logger *log.Logger) (http.Handler, error) {
	if !h.Available() {

import org.codelibs.core.io.FileUtil;
import org.codelibs.fess.crawler.exception.CrawlerSystemException;
import org.mortbay.jetty.Handler;
import org.mortbay.jetty.Server;
import org.mortbay.jetty.handler.DefaultHandler;
import org.mortbay.jetty.handler.HandlerList;
import org.mortbay.jetty.handler.ResourceHandler;
import org.mortbay.log.Log;

/**
 * @author shinsuke
 *
 */
public class CrawlerWebServer {