java code analysis tools

(): Terminates the Timer(8) Boolean java.util.TimerTask.cancel (): Terminates the TimerTaskamong these schedulexxx methods, except (1) (2), the other is able to invoke the task repeatedly, the basic difference is the difference between schedule and scheduleatfixedrate. The schedule () method is more focused on maintaining the stability of the interval time: guaranteed to be called once every period time.The Scheduleatfixedrate () method is more focused on keeping the operating frequency stable

map.isempty (); }　　iterator: Returns an iterator that iterates over the elements in this setPublic iterator　　boolean remove (Object o): If the specified element is present in this set, remove itpublic boolean remove (Object o) { return Map.Remove (o) ==present; }　　int size (): Returns the number of elements in this set public int size () { return map.size (); }Third, HashSet application example codepublic class hashsetdemo{public static void Main (string[] args)

parent class, */void addentry (int hash,k key, V value, int Bucketindex) { Createentry (hash, key, value, bucketindex); Remove eldest entry if instructed, else grow capacity if appropriate entry* */private void Addbefore (entryThe traversal iteration uses a doubly linked list to iterate through the interface directly, not here. Be able to see the source code very easy to Understand.Note that the implementation of the listing o

Java Multithreading Series--"Juc thread pool" 04 thread pool principle (iii)This chapter describes the life cycle of the thread pool. In the Java Multithreading Series-Basic concepts of 01, we've introduced threads in 5 states: New state, ready state, running state, blocking state, dead state. The thread pool also has 5 states; However, threads are different than threads, and the 5 states of the line pool a

This article brings you to the content of Java in the value of delivery and reference delivery (address delivery) between the analysis of the difference (with code), there is a certain reference value, the need for friends can refer to, I hope to help you. A value pass (pass by value) refers to a copy of the actual argument to the function when the function is c

() {returnRemovefirst (); } PublicE Removefirst () {FinalNodeFirst ; if(f = =NULL) Throw Newnosuchelementexception (); returnUnlinkfirst (f); } PrivateE Unlinkfirst (nodef) {//assert F = = First f! = null; FinalE element =F.item; FinalNodeF.next; F.item=NULL; F.next=NULL;//Help GCFirst =Next; if(Next = =NULL) Last=NULL; ElseNext.prev=NULL; Size--; Modcount++; returnelement; }The first element is deleted, the head node is also explained before;4. Other (summary)ArrayLis

Java BlockingQueue source code analysis, javablockingqueueIntroduction BlockingQueue is a multi-thread security blocking queue provided by Java concurrent. Its sub-classes include javasblockingqueue and ArrayBlockingQueue.Key APIs When it comes to queues, the insertion and deletion operations at the beginning and end a

Iterator is often used to traverse the list as follows: listNew arraylist(); List.add ("Apple"); List.add ("banana"); List.add ("watermelon"); for (iteratorlist.iterator (); Iterator.hasnext ();) { System.out.println (Iterator.next ()); }In the Java collection, the list interface inherits the collection interface, theAbstractlist class implements the list interface, and the internal class ITR in Abstractlist imp

RemoveRange (int fromIndex, int toindex) { modcount++; int nummoved = Size-toindex; System.arraycopy (Elementdata, Toindex, Elementdata, FromIndex, nummoved); Clear to let GC does its work int newSize = size-(toindex-fromindex); for (int i = newSize; i removes all elements in the list between FromIndex(inclusive) and Toindex(not included). Moves all subsequent elements to the left (decreasing their index). This call shortens the

) | | * ( First.prev==nullfirst.item!=null) */transientnode All operations around the addition and deletion of the node, see a add all the actions /***Constructsalist containingtheelementsofthespecified* Collection,intheordertheyarereturnedbythecollection ' s *iterator.** @param cthecollectionwhoseelementsaretobe placedintothislist* @throws nullpointerexception ifthespecifiedcollectionisnull*/ publiclinkedlist (collection 3. Vector ArrayList similar, the source

) {TreeSet set=NewTreeSet (); Set.add ("AAA"); Set.add ("AAA"); Set.add ("BBB"); Set.add ("Eee"); Set.add ("DDD"); Set.add ("CCC"); //Sequential Traversal TreeSetAsciteratorthroughiterator (set); //Reverse Traversal TreeSetDesciteratorthroughiterator (set); //traverse TreeSet through For-each. Not recommended! This method requires that the set be converted to an arrayForeachtreeset (set); } //Sequential Traversal TreeSet Public Static voidAsciteratorthroughiterator (TreeSet set) {System.o

Java thread pool Learning (5) -- ThreadPoolExecutor source code analysis Through the previous chapter, we learned how to create a thread pool through ThreadPoolExecutor. Next we will analyze the source code of ThreadPoolExecutor to see how it works. Let's take a look at what happened when running a task using execute (

contiguous in heap memory, so the LinkedList class features: Access to elements is not efficient, but the insertion and deletion of elements is efficient, because the node change point can be achieved. 　　The implementation class of map I just say a hashmap,treemap is not said, is added in the time, there is a certain order, but it is not important, you can use the tool class collections class method to implement the ordering of the collection elements.the bottom of the HashMap is achieved by th

The interface and implementation class of set is the simplest, and the simple reason is that its implementation is based on the actual map implementation. such as HashSet based on Hashmap,treeset based on Treemap,copyonwritearrayset based on Copyonwritearraylist.Therefore, it realizes the brief analysis. First look at the following class diagram:SetThe meaning of the set interface is that it contains equal elements, and equality is determined by the E

see a 11. * Consistent snapshot:if modcounts change during a traversal 12. * of segments computing size or checking containsvalue, then 13. * We might have a inconsistent view of state so (usually) 14. * Must retry. A.*/16.transient intModcount; 17. 18./*** The table is rehashed when its size exceeds this threshold. * (The value of this field was always */23.transient intthreshold; 24. 25./*** the Per-segment table. .*/28.transient volatileHashentry[] table;

thread on Notempty. publicpoll() { finalthis.lock; lock.lock(); try { return0null : extract(); finally { lock.unlock(); } }The poll method returns null directly when the queue is detected as empty, otherwise the team head element is removed. PublicEPoll(LongTimeout, timeunit unit)throwsinterruptedexception {LongNanos = Unit.tonanos (timeout);FinalReentrantlock lock = This. Lock; Lock.lockinterruptibly ();Try{ while(Count = =0)

();newcapacity = Integer.max_value;}Value = arrays.copyof (value, newcapacity); Copy the original data into an enlarged array to return}The reference source code, oneself in the engineering code simple realization function.byte[] bytes = new BYTE[16]; Stringbuff default initialization of source code is 16 bytesString str = "Hellowewewehellowewewe"; //bytes = arr

handling of NULL, and this strange thing can only be compared by = =.In general, it is the traversal of the array, if a matching element is found, the Fastremove is successful, the deletion returns true, otherwise false.This quick delete is nothing to be curious about: Private void fastremove (int index) { Modcount++ ; int nummoved = size-index-1; if (nummoved > 0) System.arraycopy (elementdata, index+1, Elementdata, index, nummov

(command)) {//Here is a task in the queue, and if unsuccessful, the worker is added (encapsulates the thread object)int recheck = Ctl.get ();if (! isrunning (Recheck) Remove (command))Reject (command);else if (workercountof (recheck) = = 0)Addworker (null, FALSE);}else if (!addworker (command, FALSE))Reject (command);}The above link mentions: Offer () returns immediately after placing an element in the queue, and if it happens that the element was taken away by another thread, the Offer method

stopallcomponents () stop order. I believe everyone is very easy to understand. is to start the component through Supervisor.supervise. It is also important to note that a certain amount of time is required after the channel component is started in order for all channel to be started.Besides, why stop and start first? Due to the fact that you want to load the configuration file dynamically. Once you have loaded the configuration file, you need to start all the components again. So stop all of i