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blocking state for various reasons during the run:1. The thread goes to sleep by calling the Sleep method2. The thread invokes an operation that is blocked on I/O, that is, the operation does not return to its caller until the input and output is complete;3. The thread view gets a lock that is being held by another thread.4. The thread is waiting for a trigger conditionDeath Status:There are two causes of thread death:1, run () method normal exit and natural death,2. An uncaught exception termi

1, because what type of elements in the collection can be stored. Causes the run-time classcastexception to be raised if a strong turn occurs. How to solve this problem? When you use a collection, you must explicitly specify the type of the elements in the collection. This approach is called: Generics.2, the application of generics is divided into three kinds: the class containing the generic type, containing the generic interface, containing a generic method.3. When generics are used, define th

induction method, it is proved that the use of asymptotic notation is prone to error. such as: proof O (n) must be strictly proved ≤CN, can not be said to change to do cn+n Variable transformation Sometimes changing variables can make an unknown recursive into a familiar formula. For example: "Substituting law questions""Recursive Tree Method" Recursive trees are best used to generate good guesses, and then use the surrogate method to verify

1. What is the format of the construction method? What are the precautions?A: Modifier constructor method Name (parameter list){}Note: (1) The construction method does not return a value type and does not require a write return value. Because it is for building objects, the object is created, and the method executes the end.(2) The construction method name must be consistent with the class name.2. Can the construction method be overloaded? Can I have a return statement inside?A: The construction

things.Other FAQsImportantData type issues:(1) Is there an error in the data type of the variable?(2) Are there assignments of different data types?(3) Is there a comparison of different data types?ImportantVariable Value problem:(1) Is there an error in the initialization or default value of the variable?(2) Are there overflow or underflow of variables?(3) is the accuracy of the variable sufficient?ImportantLogical judgment Question:(1) is the comparison invalid due to the accuracy reason?(2)

milliseconds to execute an expression. * SetTimeout ("Change ()", 5000);method to clear the timing clearinterval ();(1) clearinterval (id_of_setinterval)var int=self.setinterval ("Clock ()", 50)Window.clearinterval (int);(2) cleartimeout ();Cleartimeout (settimeout_variable)T=settimeout ("Timedcount ()", 1000)Cleartimeout (t)Navigator: Browser ObjectScreens: Screen ObjectsHistory: Historical object Go (); Load a specific page in the history listLocation: Path Object href: Sets or returns the fu

Function Call Model FundamentalsIt's actually a constant jump from one memory to another.function call Variable pass analysis A main program has n functions, the C + + compiler will build several heap areas? How many stack areas are there?A: A program has only one heap area and one stack area. When a function is nested, how does the C + + compiler manage the life cycle of a variable when the argument address is passed to the parameter?The upper-level variable can be used in the next

); System.out.println (e.ch); System.out.println (E.I); System.out.println (E.AA); System.out.println (E.S.AAA); } Private voidChange (String STRIII,Char[] Chaaa,integer Aaaaai,intA,stu s) {STRIII= "good"; Aaaaai=26; chaaa[0] = ' g '; AA= 11; S.AAA= 9999; }}classStu { PublicStu (intAA) { This. aaa=AA; } Public intAAA;}Output Result:GoodsssGbc22119999The above example shows that the basic data type and the string value are passed directly by the value, which

1 command Option ParametersOptions: Short option long optionParameters:LS---listDirectories: Files, path mappingsPath: The location that passes from the specified starting point to the destinationAbsolute pathRelative pathFile type-Normal fileD: Catalog fileB: Block device filesC: Character device fileL: Symbolic Link fileP: Command Pipeline fileS: Socket fileAll files have index nodes the index node is the system-to-file representation of the system record file with the identifier is the node n

From:OGG GoldenGate Extract | Pump Abends with: "TCP/IP Error 9 (Bad File number)" (Document ID 1359087.1)If the source Extract dies without communicating to the target server collector, that server would be orphaned and must be Killed. Development plans to improve the behavior in a future release (tracked via enhancement bugs 10430342), but until that time , they must is handled manually in this manner.You can determine which processes is orphans by stopping the upstream pumps and then seeing w

#include count=0;While [$C-le 100];Do touch ' wz$count ' doneLS TEST?LS test*LS Test[2-5]LS test[2-100] Only test0//errorLS test[0-9]9 test9 test19 test29Date +%y-%m-%d%h-%m-%smytime=$ (date +%y-%m-%d%h-%m-%s)Mytime= ' Date +%y-%m-%d%h-%m-%s 'Echo MyTimeInt=123echo $int + $int #123 +123echo $ (int+int) #246echo $ ($int + $int) #246((Data=int+int))echo Data #246Touch $ $Touch $\ $Touch \$\ \$Touch-fileTouch \-fileTouch./-fileRm-f./-fileTouch---FileRM---File' and ' "gg=100echo "\% \ \" $gg ' ls '

database backup (replication of changed data), transaction log backup (information in the replication transaction log), database file or filegroup backup (database large, copy part of it)Recovery model:Simple recovery (one of the top two in the backup method), full recovery (first three), bulk-Logged recovery?Database backup:Example: Create a full database backup and differential database backup, log backup, file backup for the MAGDB databaseBackup database docdb to docdb_0 with InitBackup data

name as expressionCreate default Sex_default as ' woman 'Use default values:Sp_binddefault sex_default, ' Mag_emp.sexinfo 'To view the default values:Sp_helpconstraint mag_empTo dismiss the default value:Sp_unbinddefault ' table name. Column name ', ' default value 'Sp_unbinddefault ' Mag_emp.sexinfo ', Sex_defaultDelete default values:Drop Default Sex_defaultTwo methods for implementing data integrity are compared:1. Object level different database object vs data Table Object2, the definition

process: Bin directory under startup.sh./startup.shBoot process appears java_home:source/etc/profile reboot system fileThe configuration file for the code package is copied under the classes file. War package to work, replace the configuration file, check the process, delete the WebApps process under the. War code package, copy the. War package to replace the classes configuration file to WebApps, and start the process.The replacement configuration file is due to the occasional development of n

=/root/rsyncUse Chroot=trueMax Connections=4Read Only=noList=trueUid=rootGid=rootAuth Users=testSecrets file=/etc/rsyncd.passwd36.rsync synchronization, how to delete the target data more than the data, that the source does not exist, but the target exists in the file or directory?# Rsync-av--delete/test1//test2/37. When using free to view memory usage, which value represents the amount of memory actually available?Second line: value for free38. One day you suddenly find that the company's websi

One: How to view the default gateway for Linux1. If the fixed IP is connected to the Internet, cat/etc/sysconfig/network inside the gateway2. If DHCP is on the Internet, use the route command, the default line is the gateway[Email protected] ~]# routeKernel IP Routing TableDestination Gateway genmask Flags Metric Ref use Iface192.1.1.0 255.255.255.0 U 0 0 0 eth0169.254.0.0 255.255.0.0 U 0 0 0 eth0Default 192.1.1.1 0.0.0.0 UG 0 0 0 eth03. You can also use the netstat command to viewAugust

After you create an object with a constructor, the program keeps track of the object until it expires. After the object expires, the program calls the destructor to complete the cleanup of the object.Several features of the destructor:1. There can be only one destructor, and if there is no explicit definition, the compiler will automatically generate a default destructor;2. Destructors cannot be overloaded;When the destructor is called:1. If you create a static storage class object, the destruct

What is an array?An array is an unordered sequence of elements, and all elements in an array have the same type.Declaring an array variable:Int[] A; the size of the array is not part of the Declaration;To create an instance of an array:A=new Int[3];Initialize the array variable:Int[] A=new int[2]{1,2};Int[] a={1,2};Time[] schedule={new time, New Time (5,30)};To create an implicitly-typed array:var name=new[]{new {name= "John", age=44},new {name= "Diana", age=45}};To iterate over an array:You can

only one class object, regardless of the number of objects generated).Package Com.cao.basics.thread;public class Threadsynchtest {public static void main (string[] args) {c c = new C (); T1 T1 = new T1 (c);//c = new C (); T2 t2 = new T2 (c); Thread t = new thread (t2); T1.start (); try {thread.sleep ($);} catch (Interruptedexception e) {e.printstacktrace ();} T.start ();}} Class C{//private Object Object1 = new Object (),//private object object2 = new Object ();p ublic synchronized void Hello (

number I, delete the number of I, statistics I to the number of J andThe principle of the tree array is to add an auxiliary sequence C array, which makes C[i]=a[i-2k+1]+a[i-2k+2]+...+a[i], where K is the number of the end 0 in the binary form of I.1#include 2 #defineFi first3 #defineSe Second4 #definePB Push_back5 #defineFio Ios::sync_with_stdio (false); Cin.tie (0);6 #definePII pair7 #defineVI vector8 #defineVC Vector9 #defineMii mapTen #defineSi (a) scanf ("%d", a) One #defineSS (a) scanf ("%