How many newWatchService can I make ?
try{
for(Path path : PathList) {
watcher = path.getFileSystem().newWatchService();
} catch (IOException e) {
log.error(e);
}
}
--> result: IOExeption: too many open files...
I think you are supposed to create only one watcher service, but register [m]any paths to it.
As per the example given by Oracle docs (https://docs.oracle.com/javase/tutorial/essential/io/walk.html), there is only one watch service created, as a member variable of WatchDir class. Note the "this.watcher"
public class WatchDir {
private final WatchService watcher;
elsewhere in the class...
/**
* Creates a WatchService and registers the given directory
*/
WatchDir(Path dir, boolean recursive) throws IOException {
this.watcher = FileSystems.getDefault().newWatchService();
The same service is used for registering all paths inside a given folder recursively.
Finally, the registration happens here...
/**
* Register the given directory with the WatchService
*/
private void register(Path dir) throws IOException {
WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
Related
In my Spring Camel app, I try to move or delete a file base on the destinationFolder property. If destinationFolder=null, I want the file to be deleted. If destinationFolder!=null, I want the file to be moved to destinationFolder.
String destinationFolder;
//In the Camel routeBuilder:
from("file://C:/folder1?move=" + destinationFolder)
What will happen in destinationFolder is null? Does the file get move to default location?
When I set destinationFolder=null, I see the file is deleted in folder1.
If you set the move option then the file component will move the file, you cannot set it to null and then have it automatic delete the file. By default the file is moved to a folder named .camel.
So either set delete=true or set move to some folder name to move the files.
First, you should know when to use "move", "delete" &"noop" and how it will works in Apache camel
Note :1) If your destination path is not existed then file will delete automatically.
Note :2) If you are not used "noop=true" in Camel URL then file file will delete(if your destination path is null)
Reference : - enter link description here
Basic Test Code:
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.impl.DefaultCamelContext;
public class SFTPTest {
public static void main(String[] args) throws Exception {
DefaultCamelContext ctx = null;
try{
ctx = new DefaultCamelContext();
ctx.addRoutes(new RouteBuilder() {
#Override
public void configure() throws Exception {
String filepath = "file:///camelexample/?fileName=test.txt&move=null";
from(filepath)
.log("File processed");
}
});
ctx.start();
Thread.sleep(5000);
ctx.stop();
}catch (Exception e){
System.err.println("Exception is : "+e.getLocalizedMessage());
}finally {
try{
ctx.stop();
}catch (Exception e){
System.err.println("Exception is : "+e.getLocalizedMessage());
}
}
}
}
I would like to generate a blog posts overview. For that I want to read the html files from a folder inside the templates folder in the resources folder where Spring Boot stores its templates.
I tried that but it doesnt return an error but also list no files.
What is the way to go here?
Thanks
#Controller
public class Route {
#Autowired
private ResourceLoader resourceLoader;
#RequestMapping("/")
public String home() throws IOException {
final String path = "templates/blog";
final Resource res = resourceLoader.getResource("templates/blog");
try (final BufferedReader reader = new BufferedReader(new InputStreamReader(res.getInputStream()))) {
reader.lines().forEachOrdered(System.out::println);
}
return "blog/a";
}
}
#Controller
public class Route {
#Value("classpath:templates/blog/*")
private Resource[] resources;
#RequestMapping("/")
public String home() throws IOException {
for (final Resource res : resources) {
System.out.println(res.getFilename());
}
return "blog/a";
}
}
did the trick to me.
You should be able to achieve this using NIO2.
In order for NIO2 to work, it requires the concept of FileSystem, and one can be created from the jar URI. Then this file system can be used with Files/Paths.
The code below contains two branches - the first handles loading the files from inside Jar, the second branch - when the code runs from IDE or via "mvn spring-boot:run".
All streams are being used via try-with-resources so they will be auto-closed.
The find function starts from the top of the file system and recursively searches for html files.
public static void readFile(String location) throws URISyntaxException {
URI uri = Objects.requireNonNull(ReadFromJar.class.getClassLoader().getResource(location)).toURI();
if (uri.getScheme().equals("jar")) { //inside jar
try (FileSystem fs = FileSystems.newFileSystem(uri, Collections.emptyMap())) { //build a new FS that represents the jar's contents
Files.find(fs.getPath("/"), 10, (path, fileAttr) -> // control the search depth (e.g. 10)
fileAttr.isRegularFile() //match only files
&& path.toString().contains("blog") //match only files in paths containing "blog"
&& path.getFileName().toString().matches(".*\\.html")) // match only html files
.forEach(ReadFromJar::printFileContent);
} catch (IOException ex) {
ex.printStackTrace();
}
}
else { //from IDE or spring-boot:run
final Path path = Paths.get(uri);
try (DirectoryStream<Path> dirStream = Files.newDirectoryStream(path)) {
dirStream.forEach(ReadFromJar::printFileContent);
} catch (IOException e) {
e.printStackTrace();
}
}
}
private static void printFileContent(final Path file) {
try {
System.out.println("Full path: " + file.toAbsolutePath().toString());
Files.lines(file).forEach(System.out::println);
} catch (IOException e) {
e.printStackTrace();
}
}
I own a spring application and want to add camel routes dynamically during my application startup.End points are configured in property file and are loaded at run time.
Using Java DSL, i am using for loop to create all routes,
for(int i=0;i<allEndPoints;i++)
{
DynamcRouteBuilder route = new
DynamcRouteBuilder(context,fromUri,toUri)
camelContext.addRoutes(route)
}
private class DynamcRouteBuilder extends RouteBuilder {
private final String from;
private final String to;
private MyDynamcRouteBuilder(CamelContext context, String from, String to) {
super(context);
this.from = from;
this.to = to;
}
#Override
public void configure() throws Exception {
from(from).to(to);
}
}
but getting below exception while creating first route itself
Failed to create route file_routedirect: at: >>> OnException[[class org.apache.camel.component.file.GenericFileOperationFailedException] -> [Log[Exception trapped ${exception.class}], process[Processor#0x0]]] <<< in route: Route(file_routedirect:)[[From[direct:... because of ref must be specified on: process[Processor#0x0]\n\ta
Not sure about it- what is the issue ? Can someone has any suggestion or fix for this. Thanks
Well, to create routes in an iteration it is nice to have some object that holds the different values for one route. Let's call this RouteConfiguration, a simple POJO with String fields for from, to and routeId.
We are using YAML files to configure such things because you have a real List format instead of using "flat lists" in property files (route[0].from, route[0].to).
If you use Spring you can directly transform such a "list of object configurations" into a Collection of objects using #ConfigurationProperties
When you are able to create such a Collection of value objects, you can simply iterate over it. Here is a strongly simplified example.
#Override
public void configure() {
createConfiguredRoutes();
}
void createConfiguredRoutes() {
configuration.getRoutes().forEach(this::addRouteToContext);
}
// Implement route that is added in an iteration
private void addRouteToContext(final RouteConfiguration routeConfiguration) throws Exception {
this.camelContext.addRoutes(new RouteBuilder() {
#Override
public void configure() throws Exception {
from(routeConfiguration.getFrom())
.routeId(routeConfiguration.getRouteId())
...
.to(routeConfiguration.getTo());
}
});
}
I'm still learning SNMP, so be gentle please.
I did an agent with snmp4j and it seems to be working, i have a scalar that should register how much time has passed since the agent started.
I just have to do the agent, then i would like to see the value of the scalar with net-snmp.
The problem is, when i start the agent i set the my scalar SystemUpTime to 0, then i try to update SystemUpTime everytime someone tries to check it with net-snmp that value doesnt change.
How can i get my agent to update SystemUpTime everytime something tries to access it?
I have a method MOScalar getSystemUpTime since it updates SystemUpTime before returning it and i thought that it would do the job, but it is not working.
What do u guys sugest?
EDIT ( my agent code, ive taken off some of the mandatory methods to short this thing a bit )
public class Agent extends BaseAgent {
// not needed but very useful of course
static {
LogFactory.setLogFactory(new Log4jLogFactory());
}
static long starttime=0;
private String address;
static OID oid= new OID(".1.3.6.1.4.1.1.1.0");
public static MOScalar sysUpTime;
private static MOFactory moFactory =
DefaultMOFactory.getInstance();
public Agent(String address) throws IOException {
// These files does not exist and are not used but has to be specified
// Read snmp4j docs for more info
super(new File("conf.agent"), new File("bootCounter.agent"),
new CommandProcessor(
new OctetString(MPv3.createLocalEngineID())));
this.address = address;
}
/**
* Clients can register the MO they need
*/
public void registerManagedObject(ManagedObject mo) {
try {
server.register(mo, null);
System.out.println("MIB FILLED!");
} catch (DuplicateRegistrationException ex) {
throw new RuntimeException(ex);
}
}
/**
* Start method invokes some initialization methods needed to
* start the agent
* #throws IOException
*/
public void start() throws IOException {
init();
// This method reads some old config from a file and causes
// unexpected behavior.
// loadConfig(ImportModes.REPLACE_CREATE);
addShutdownHook();
getServer().addContext(new OctetString("public"));
finishInit();
run();
sendColdStartNotification();
}
protected void unregisterManagedObjects() {
// here we should unregister those objects previously registered...
}
/**
* The table of community strings configured in the SNMP
* engine's Local Configuration Datastore (LCD).
*
* We only configure one, "public".
*/
protected void addCommunities(SnmpCommunityMIB communityMIB) {
Variable[] com2sec = new Variable[] {
new OctetString("public"), // community name
new OctetString("cpublic"), // security name
getAgent().getContextEngineID(), // local engine ID
new OctetString("public"), // default context name
new OctetString(), // transport tag
new Integer32(StorageType.nonVolatile), // storage type
new Integer32(RowStatus.active) // row status
};
}
public static void main(String[] args) throws IOException, InterruptedException {
Agent agent = new Agent("127.0.0.1/6666");
sysUpTime=moFactory.createScalar(oid,
moFactory.createAccess(MOAccessImpl.ACCESSIBLE_FOR_READ_ONLY),
new TimeTicks(0));
starttime=System.currentTimeMillis();
agent.registerManagedObject(sysUpTime);
agent.start();
while(true) {
System.out.println("Agent running...");
Thread.sleep(5000);
}
}
public MOScalar getSystemID() {
Variable var = new Integer32((int) (System.currentTimeMillis() - starttime));
sysUpTime.setValue(var);
return sysUpTime;
}
}
According to my requirement, I need to externalize the message.properties file (Keep outside from war file) and in same time it should be automatically re loadable on update.
So I achieved both by following code and its working fine with Jetty Server. But in when I use Tomcat Server that externalized property file is not picking up by the system, instead its uses only the file inside the war.
public final class Messages
{
public static final String BUNDLE_NAME = "com.sample.project.core.ui.resources.messages";
// private static ResourceBundle resourceBundle = ResourceBundle.getBundle(BUNDLE_NAME);
private static ResourceBundle resourceBundle;
private static final Logger LOGGER = Logger.getLogger(Messages.class);
private static ReloadableResourceBundleMessageSource messageSource;
static
{
try
{
FileInputStream fis =
new FileInputStream(System.getProperty("resources.messages.file.path"));
resourceBundle = new PropertyResourceBundle(fis);
}
catch (FileNotFoundException e)
{
LOGGER.error("messages.properties file not found: " + e);
resourceBundle = ResourceBundle.getBundle(BUNDLE_NAME);
}
catch (Exception e)
{
LOGGER.error("messages.properties file reading failed: " + e);
resourceBundle = ResourceBundle.getBundle(BUNDLE_NAME);
}
}
private Messages()
{
}
/**
* <p>
* setter methos to ReloadableResourceBundleMessageSource object.
* </p>
*
*
* #param inMessageSource
* set reloadable resources bundle
**/
public static void setMessageSource(final ReloadableResourceBundleMessageSource inMessageSource)
{
Messages.messageSource = inMessageSource;
Messages.messageSource.setBasename(System.getProperty("resources.messages.file.path"));
}
/**
* <p>
* Resolve a message by a key and argument replacements.
* </p>
*
* #see MessageFormat#format(String, Object...)
* #param key
* the message to look up
* #param arguments
* optional message arguments
* #return the resolved message
**/
public static String getMessage(final String key, final Object... arguments)
{
try
{
if (messageSource != null)
{
return messageSource.getMessage(key, arguments, Locale.getDefault());
}
else
{
if (arguments != null)
return MessageFormat.format(resourceBundle.getString(key), arguments);
return resourceBundle.getString(key);
}
}
catch (NoSuchMessageException e)
{
LOGGER.error("Message key not found: " + key);
return '!' + key + '!';
}
catch (MissingResourceException e)
{
LOGGER.error("Message key not found: " + key);
return '!' + key + '!';
}
}
}
(Here file path I'm passing as a VM argument using "resources.messages.file.path" key)
First I thought it was a problem with accessing the file system and tried many ways. Then I heard about catalina.policy file and I added some lines like this..
grant codeBase "file:${catalina.base}/webapps/sample.war/-" {
permission java.security.AllPermission;
permission java.io.FilePermission "file:${catalina.base}${file.separator}webapps${file.separator}messages.properties", "read, write";
permission java.util.PropertyPermission "resources.messages.file.path", "read";
}
But non of them gave me luck. I'm desperate. Any idea what this issue is? Please help me. Thank you in advance. (Tested on Tomcat6)
Finally I found where I screwed up.
This setter method of messageSource should not be static and I removed static access of messageSource
messageSource = inMessageSource;
messageSource.setBasename(System.getProperty("resources.messages.file.path"));
Now code is working fine. And no need of that permission entry in catalina.policy file. Thanks to everyone who helped me.