java profiling tools

Before testing, you need to import JUnit's two packages, respectivelyjunit:4.12;hamcrest-core:1.11. Basic Test Label@Test, @Before, @After2. Group TestingSometimes multiple test files, if one goes to execute is certainly a waste of time, then how to do it?If there are Firtest.java,sectest.java now, there are multiple methods in each test class, how do you want to test this file together?Create a new Java test file named Grouptest, and then write the c

elements to the queue is "C", "A", "B", and the Order of removal is "a", "B", "C", which can be seen by the nature of its "precedence".SummarizeThis article introduces three commonly used tool classes, threadlocal is used to solve the problem of multi-threaded sharing the same variable, it is equivalent to creating a thread object as a key to the target object as a value of a map, but actually and map is different, For example, a map object does not garbage-reclaims the corresponding value afte

)); StringBuffer SB=NewStringBuffer (); String Line=Reader.readline (); while(Line! =NULL) {sb.append (line); Line=Reader.readline (); } jsonobject Jsonobject=Jsonobject.parseobject (sb.tostring ()); System.out.println (Result.getmessagecount ()); Break; } } Catch(IOException e) {//TODO auto-generated Catch blockE.printstacktrace (); } LocalDateTime End=Localdatetime.now (); Duration Duration=Duration.between (start, end); System.out.println ("Custom GP Run Ti

) { Try{rs.close (); } Catch(SQLException e) {e.printstacktrace (); } } //Waiting for garbage collectionrs =NULL; } } Tool Testing: Packagecom.test.utils; Importjava.sql.Connection;Importjava.sql.PreparedStatement;ImportJava.sql.ResultSet;Importjava.sql.SQLException; Importorg.junit.Test; Public classjdbctest {@Test Public voidAdd () {Connection conn=NULL; PreparedStatement St=NULL; ResultSet RS=NULL; Try { //Get Connectionsconn =jdbcutils.getconnection

(Exception e) {e.printstacktrace (); } } /*** Delete and change operation * *@paramSQL * SQL command *@paramparam * Parameters *@return */ Public Static intexecutupdate (Connection conn,string sql, object[] param) {intresult = 0; PreparedStatement pstmt=NULL; Try{pstmt=conn.preparestatement (SQL); if(param! =NULL) { for(inti = 0; i ) {Pstmt.setobject (i+ 1, Param[i]); }} result=pstmt.executeupdate (); } Catch(Exception e) {e.printstacktrace (); } finally{close

Originally in the last company, a whole year to do tools, improve production, the project is particularly large, so the total savings for the old club of about 500K dollars.(in addition to praise, I personally do not have any benefits, the leaders are ladder, depressed)To the new company, it is also ready to develop some tools to improve production. Recently looking at net MVC and spring MVC data. So you wa

First, the JDK with the environment;1. JDK Mind Map2. Test code:Attention should be paid to the distinction between the case of the point class name, the symbol for the English input method,;.Class Hello{public static void Main (String [] args){System.out.println ("Java");System.out.println ("Hello World");System.out.println ("Hello World");System.out.println ("# # # # #");System.out.println ("# # #");System.out.println ("# #");System.out.println ("#"

Advantages and disadvantages of essential tools for Java professionals) 1. Notepad ++ In my career, I used to work for multiple companies, and this tool has always been around me. It is no exaggeration to say that Notepad ++ is the best replacement tool for my notebook. I have been using this software to edit xml, scripts, or simply write notes. This software is most appreciated because every document I op

When a problem occurs in the online system, you need to record the current running status of the system. To sum up, you need to pay attention to the following aspects:1. Load: -- top commandOn Linux, execute top and other commands, pay attention to the overview of load, memory, CPU and other systems, and pay attention to the processes that consume a lot of CPU and memory.Use top-H and sort the CPU by SHIFT + P to find the thread that currently occupies the most CPU. (Top-u BPM-h),-H display by t

storage is Sunday So it's the same way as the month. SYSTEM.OUT.PRINTLN (Weeks[week]); System.out.println (Calendar.get (calendar.day_of_month)); System.out.println (Calendar.get (Calendar.hour_of_day));//24 hours String str = String.Format ("%d-%d month-%d Day", Year,month, day);//Gets the string of the format we want System.out.println (str);//%s string%c char%d int%f float Double the various types of SYSTEM.OUT.PRINTLN (String.Format ("%.2f", 10/3.0) to be used when formatting, *2015-7-108 m

Eclipse Plug-in class Fat jar Excellent: multiple jar package composition; Missing: folder structure not maintained Fat Jar Eclipse Plug-in is a gadget that can package all the resources of Eclipse Java project into an executable jar file, so that you can easily complete a variety of packaging tasks, and we often come to the jar package, But Eclipse's own packaged jar doesn't seem to be enough, and the fat jar is a plug-in for eclipse, e

(number of columns) how much, in the absence of a row engine, there will be a critical point, below the critical point when you can export the success of the exported content has more than sheet, otherwise the export failed, the content is invalid. Therefore, for large data volumes, it is common to use the row engine to represent, in which case the export Excel is always successful. When you export Excel in a large data volume report that has the row engine enabled , it is split into multiple .

(number of columns) how much, in the absence of a row engine, there will be a critical point, below the critical point when you can export the success of the exported content has more than sheet, otherwise the export failed, the content is invalid. Therefore, for large data volumes, it is common to use the row engine to represent, in which case the export Excel is always successful. When you export Excel in a large data volume report that has the row engine enabled , it is split into multiple .

Basic Java Web tools-BaseDao and javawebbasedao 1 package dao; 2 3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 import java.sql.PreparedStatement; 6 import java.sql.ResultSet; 7 import java.sql.SQLException; 8 import java.sql.Statement; 9 10 public class BaseDao {11 private static String URL = "jdbc:sqlserver://localhost:1433;DatabaseName=StudentManageSys";12 private static Strin

Public classStrutils { Public Static FinalString utf_8 = "UTF-8"; /*** Remove the useless 0 after the decimal string*/ Public Staticstring Replacethetailzero (String value) {if(Stringutils.isempty (value)) {returnvalue; } if(Value.indexof (".") > 0) {Value=value.replaceall ("0+?$", "" ");//remove the useless 0 behindValue =value.replaceall ("[.] $", "");//the decimal point is removed if all zeros are followed by a decimal point } returnvalue; } /*** UTF-8

Determine if the phone number and phone numberpackagecom.rk.utils;importjava.util.regex.matcher;importjava.util.regex.pattern;public classregexutils{/*** Mobile phone number verification ** @param str* @return Verify by returning True*/publicstaticbooleanismobile (STRINGNBSP;STR) {patternp= Null Matcherm=null;booleanb=false;p=pattern.compile ("^[1][3,4,5,8][ 0-9]{9}$ ");// Verify the phone number m=p.matcher (str); b=m.matches (); returnb;} /*** phone number verification ** @param str* @return

voidmain (String [] args) {7Cyclicbarrier Cyclicbarrier =NewCyclicbarrier (3,NewRunnable () {8 Public voidrun () {9System.out.println (Thread.CurrentThread (). GetName () + "======");Ten Try { OneThread.Sleep ((Long) (Math.random () *10000)); A}Catch(Exception e) { - e.printstacktrace (); - } theSystem.out.println (Thread.CurrentThread (). GetName () + "======>"); - } - }); -Executorservice executorservice= Executors.newfixedthrea

signaturesSignature:data.signature,//required, signature, see Appendix 1Jsapilist: [' chooseimage ', ' uploadimage ', ' downloadimage ', ' previewimage ']//must fill in, need to use the JS interface list, all JS interface list See Appendix 2 }); Wx.ready (function(){ //layer.msg ("JSSDK initialization succeeded"); //after the config information is validated, the Ready method is executed, and all interface calls must be completed by the Confi

letters: lowercase letters are converted to uppercase, uppercase and direct return if(Ch >= ' a ' ch ) return(Char) (CH-' a ' + ' a '); if(Ch >= ' A ' ch ) returnch; //processing of non-English letters: convert to the first letter, and then determine whether within the Code table range,//if not, return directly. //If so, it is judged within the Code table. intGB = Gbvalue (CH);//Kanji Conversion First letter if(GB //before the Code table inter

smaller than itSystem.out.println (Math.ceil (10.55));//the first integer larger than itSystem.out.println (Math.pow (2,3));//3 times for index 2System.out.println (Math.Round (10.6));//RoundingSystem.out.println (MATH.SQRT (64));//the first integer smaller than itSystem.out.println (Math.random ()); Random random1=NewRandom (); System.out.println (Random1.nextint ()); Random Random2=NewRandom (10);//The random number does not changeSystem.out.println (Random2.nextint ()); Random