java coding practice

is compared, if the same, it means that there has not been a write operation, the result of the original traversal is returned, if not the same, the process is repeated again, if not the same, It is necessary to lock all the segment and then one through. Public intsize () {//Try a few times to get accurate count. On failure due to//continuous async changes in table, resort to locking. FinalSegment This. Segments; intsize; BooleanOverflow//true if size overflows LongSum//Sum of mo

Kotlin is a new JVM-based language that can be seen as the extended language of Java, developed by JetBrains, who first saw him in the company's Android team when they saw them using the Kotlin to develop Android, suddenly feeling curious, and then slowly studied the prophecy.Why to develop and use the Kotlin language, the official saying is:Concise safeversatileinteroperableAnd cite an example:Nullif for youfun calculatetotal (obj:any) { if (obj is

1, Tasks/main.yml ----Name:mkdir Necessary Directory File:path=/usr/java/state=directory mode=0755 -Name:unzip JDK unarchive:src={{Jdk_package_name}} dest=/usr/java/ -Name:set Envlineinfile:dest={{Env_file}} insertafter={{item.position}} line={{Item.value}} state=presentWith_items:-{position:eof,value: "\ n"}-{position:eof,value: "Export java_home=/usr/

{@Override Public voidrun () { for(inti=1;i) {Random R=NewRandom (); intN=r.nextint (1000); Try{thread.sleep (n); } Catch(interruptedexception e) {e.printstacktrace (); } System.out.println ("I first" +i+ "Want to go:" +Thread.CurrentThread (). GetName ()); if(i==10) {System.out.println ("To Go is:" +Thread.CurrentThread (). GetName ()); System.exit (0); } } } Public Static voidMain (string[] args) {Thread th=NewThread (NewTest7 ()); Th.setname (Beijing); Thread Th1=NewThr

PackageLianxiti; Public classCat {PrivateString name; PrivateString color; Private intAge ; PublicString GetName () {returnname; } Public voidsetName (String name) { This. name=name; } PublicString GetColor () {returncolor; } Public voidsetcolor (String color) { This. color=color; } Public intGetage () {returnAge ; } Public voidSetage (intAge ) { This. Age =Age ; } //Behavior//Display Name Public voidShowName () {System.out.println ("The cat's name is:" +

String str = "ASDFGHJKL"; String str1= "ASD"; //Index comparison by first letter if(Str.indexof ("asd") = = 0) {System.out.println ("True"); } String str2= "JKL"; if(Str.lastindexof ("jkl") = = Str.length ()-str2.length ()) {System.out.println ("True"); } //to compare by intercepting a stringSystem.out.println ((str.substring (0, Str1.length ())). Equals (STR1)); System.out.println (Str.substring (Str.length ()-Str2.length ())). Equals (STR2));

[Java concurrent programming practice] ----- "J. U. C": CLH queue lock CLH queue is a queue that maintains a group of threads strictly in FIFO mode in AQS. He is able to ensure that there is no hunger and strict first-come Service Fairness. It is a CLH queue node: The node QNode in the clh queue contains a locked field. This field indicates whether the node needs to obtain the lock. If it is set to true

(Object obj) {if(! (objinstanceofStudent))Throw NewRuntimeException ("not a student."); Student stu= (Student) obj;if( This. Zongreturn 1;Else if( This. Zong==stu.zong)return This. Name.compareto (Stu.name);return-1; }}class studentinfoutil{ Public StaticSetgetstudents()throwsIOException {BufferedReader bur=NewBufferedReader (NewInputStreamReader (system.in)); String line=NULL; SetNewTreeset while((Line=bur.readline ())! =NULL) {if(Line.equals ("Over")) Break; String[] Info=line.split ("

"Implementation Interface"AnalysisThe whole with default borderlayout (border layout), divided into upper and lower, respectively, with three JPanel storage;On: A picture, with JLabel;Under: Three buttons JButtonMiddle: Stored with a jtabbedpane (tab)Each option is a GridLayout (grid layout)Four JLabel, one JTextField, one jpassword, one JButton, two jcheckbox (check box)CodePackage Start;import java.awt.*;//must be introduced in two packages import Javax.swing.*;//public class Main extends jfra

, the minimum value of the vector in the corresponding query interval. Sample Input7 41-1-4 8 1 2-70 01 34 50 6Sample Output1-41-7Sample DescriptionThe first query [0,0] means min{a[0]}=min{1}=1The second query [1,3] means min{a[1],a[2],a[3]}=min{-1,-4,8}=-4The third query [4,5] means min{a[4],a[5]}=min{1,2}=1the fourth query [0,6] means querying the entire vector, seeking min{a[0..6]}=min{1,-1,-4,8,1,2,-7}=-7data size and conventions12 Solutions The specific code is as follows:ImportJava.util.S

=NewString[32];4 for(inti = 0; i ) {5Strings[i] = integer.tobinarystring (i);//decimal conversion to 2 binary6 //0 in front of numbers not enough 5 digits7 if(strings[i].length () = = 1) {//1-digit number8Strings[i] = "0000" +Strings[i];9}Else if(Strings[i].length () ==2) {TenStrings[i] = "000" +Strings[i]; One}Else if(Strings[i].length () ==3) { AStrings[i] = "00" +Strings[i]; -}Else if(Strings[i].length () ==4) { -Strings[i] = "0" +Strings[i]; the}Else{ -Strings[i] =Stri

=NewScanner (system.in); intn =In.nextint (); intm =In.nextint (); VectorNewVector(); for(inti = 0;i ) List.add (In.nextint ()); for(inti = 0;i ) {String operation=In.next (); if(Operation.equals ("ADD")) { intP =In.nextint (); intQ =In.nextint (); intj =List.indexof (P); List.add (J, Q); } Else if(Operation.equals ("DEL")) { intP =In.nextint (); intj =List.indexof (P); List.remove (j); }} System.out.println (List.size ()); for

the 3-digit number is in num case Public voidPrintresult (intKintL) { for(inti = 0;i ) dp[1][i] = 1;//target number lowest bitInitialize to 0~k-1 in turn, with each number appearing only once for(inti = 2;i //the position of the number, the highest bit is L, the lowest bit is 1 for(intj = 0;j ) { for(intF = 0;f ) { if(F-1! = J F + 1! =j) {Dp[i][j]+ = Dp[i-1][f]; DP[I][J]%=MoD; } } } } intsu

){System.out.println (year+ "is a leap year");}Else{System.out.println (year+ "Not a leap year");}*//*SYSTEM.OUT.PRINTLN ("Input Gender: Height: Weight:");//Determine whether the figure is standardScanner sc = new Scanner (system.in);String sex = Sc.nextline ();Double height = sc.nextdouble ();Double weight = sc.nextdouble ();Double Biao;if (Sex.equals ("male")){Biao = height-100;if (biao-3{System.out.println ("good");}else if (biao-3>height){System.out.println ("thin");}Else{System.out.println

standard weightNote:The meaning of the standard body weight: Height-weight (kg) and 100 (110) Subtract, the difference is more than 3 is thin, less than 3 is overweight, between 3 and 3 is the standard. Scanner sc=new Scanner (system.in); System.out.println ("Please enter gender (male or female):"); String Sex=sc.next (); System.out.println ("Please enter height:"); int height=sc.nextint (); System.out.println ("Please enter weight (kg):"), int weight=sc.nextint (), int a=height-

-------------------------------------------------------------------------------------------Ideas See the Jin SAC 2-------------------------------------------------------------------------------------------Algorithm1 ImportJava.util.Scanner;2 Public classMain {3 Public Static voidMain (string[] args) {4Scanner sc =NewScanner (system.in);5 Double[] x =New Double[4];6 Double[] y =New Double[4];7 Double[] Z =New Double[4];8 for(inti=0;i){9X[i] =sc.nextdouble ()

node of first start node for(inti = 0;child! = 0;i++) { child=tree[start][i]; if(child! = Root) {//prevent the child from start from becoming the father of startDFS (child, start); dp[start][1] + = dp[child][0];//start backtracking when the child node does not have a children nodedp[start][0] + = (dp[child][1] > dp[child][0]? dp[child][1]: dp[child][0]); } } } public Static voidmain (string[] Args) {main test=NewMain (); Scanner in=NewScanner (system.in); intn =In.next

login authentication method, the parameter is the user object (which can also be a username and password), is verified by returning true, otherwise false is returned.Logout (String name): Resets the specified user (username name) from the logon state to a non-logon state. The task of this project simple processing, direct output "log out" a line of information can be.Register (user usr): Writes the incoming new user usr to the data file. Returns true to indicate an increase in success and false

@ Interface indicates that this is an annotation type @ Retention three policies are provided Retentionpolicy. runtime: not only in the source code stage, but also in the JVM where the annotation confidence is added during the runtime. Retentionpolicy. Class: in the source code stage, the annotation information is saved during the compilation stage. Annotation @ retention default value. Retentionpolicy. Source: saves annotation information in the source code stage. @ Target indicates wh

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