itil fundamentals

Switch statements in Java:Here expression control expressions can only have data types of byte, short, char, int four integer types and enumeration types, and cannot be of type Boolean;Java7 (1.7) improved the Switch Branch statement;Java7 allows the control expression in the switch statement to be of type java.lang.String ( cannot be stringbuffer or StringBuilder)Switch (expression){Case Condition1:{statement (s);Break}Case Condition2:{statement (s);Break}Case Condition3:{statement (s);Break}..

(); atSystem.out.println ("sub.filed =" + Sub.field + -", Sub.getfield () =" + Sub.getfield () + -", Sub.getsuperfield () =" +Sub.getsuperfield ()); - } -}Output:sup.filed = 0, Sup.getfield () = 1sub.filed = 1, Sub.getfield () = 1, Sub.getsuperfield () = 0Analysis:The sub subclass actually contains two fields called field, whereas the default domain generated when referencing field in sub is not a super version of the Field field, so in order to get Super.field, you must explicitly indicate

= List.iterator ();//While (It.hasnext ()) {//string str = (string) it.next ();//if (str.equals ("Polo")) {//List.add ("Pony");// }// }Listiterator listit=List.listiterator (); while(Listit.hasnext ()) {String str=(String) listit.next (); if(Str.equals ("Polo") {Listit.add ("Pony"); } if(Str.equals ("Shery") {Listit.add ("Keity"); }} System.out.println (list); for(inti = 0; I ){ if(List.get (i). Equals ("Polo")) {List.add ("Pony"); } i

After the transformation, began to enter the learning time, the following is the collation of learning notes C # and Java some differences between1, = = and equalsIn C #, the comparison of strings can be = = to compare, but in java use = = has always been false, originally in Java = = is used to see whether two references to the same memory address, equals is the value of the comparison object is equal, the total known string is the reference type of the2, switch the differenceIn C #, after the

Public StaticDate stringtodate (string s, string format) the throwsParseException { + return NewSimpleDateFormat (format). Parse (s); - } $}2. Dateutildemo. Java, as follows:1 Packagecn.itcast_04;2 3 Importjava.text.ParseException;4 Importjava.util.Date;5 6 /*7 * Test of Tool class8 */9 Public classDateutildemo {Ten Public Static voidMain (string[] args)throwsParseException { OneDate d =NewDate (); A //YYYY-MM-DD HH:mm:ss -String s = dateutil.datetos

1. The origin of the collection:We are learning object-oriented language, and object-oriented language is the description of things through objects, in order to facilitate the operation of multiple objects, we have to store these multiple objects. To store multiple objects, you cannot be a basic variable, but rather a variable of a container type, what are the container types in the knowledge we have learned? Arrays and StringBuffer. But what? The result of StringBuffer is a string that does not

(' A ')); -System.out.println ("isdigit:" + character.isdigit (' a ')); -System.out.println ("isdigit:" + character.isdigit (' 0 '))); -System.out.println ("-----------------------------------------"); - //Public Static char touppercase (char ch): Converts the given character to uppercase characters -System.out.println ("toUpperCase:" + character.touppercase (' A ')); inSystem.out.println ("toUpperCase:" + character.touppercase (' a ')); -System.out.println ("---------------------------

multiplicand) A * Public BigDecimal Divide (BigDecimal divisor) - * Public BigDecimal Divide (BigDecimal divisor,int scale,int roundingmode): quotient, several decimals, how to take out - */ the Public classBigdecimaldemo { - Public Static voidMain (string[] args) { - //System.out.println (0.09 + 0.01); - //System.out.println (1.0-0.32); + //System.out.println (1.015 *); - //System.out.println (1.301/100); + ABigDecimal BD1 =NewBigDecimal ("0.09"); atBigD

long - * Float float - * Double double the * Char Character - * Boolean boolean - * - * Used for conversions between basic data types and strings. + */ - Public classIntegerdemo { + Public Static voidMain (string[] args) { A //No, the trouble is coming. at //Public static String tobinarystring (int i) -System.out.println (integer.tobinarystring (100)); - //Public static String tooctalstring (int i) -System.out.println (integer.tooctalstring (100)); -

= new float (F1);Double D1 = F1.doublevalue ();e.g: double--->intDouble D1 = 100.00;Double D1 = new double (d1);int i1 = D1.intvalue ();(6) Conversion of string types to other data typesClass Test {public static void Main (String args[]) {int i1 = 10;float f1 = 3.14f;Double D1 = 3.1415926;Integer I1 = new Integer (i1);float F1 = new float (F1);Double D1 = new double (d1);String SI1 = i1.tostring ();String sf1 = F1 . toString ();String SD1 = D1. toString ();System.out.println ("SI1" +SI1);System

responsible for accepting user input, and informs the second class object (Checkerboard object) The change of the chess piece layout, the Checkerboard object receives the change of the chess piece to be responsible to show this change on the screen, and uses the third kind of object (rule system) to decide the chess game.For a novice, want to put the object-oriented thinking in the development of the use of the easy, is not a simple thing, has been said object-oriented is a kind of thought, tha

immediately but may be satisfied at some point in the future, and these four forms are handled differently: the first is to throw an exception, and the second is to return a special value (null or false, depending on the operation), the third is to block the current thread indefinitely until the operation succeeds, and the fourth is to block only within the given maximum time limit before discarding. These methods are summarized in the following table: Throw except

("StartsWith:" + s1.startswith ("H")); ASystem.out.println ("StartsWith:" + s1.startswith ("Hello")); theSystem.out.println ("StartsWith:" + S1.startswith ("World"))); +System.out.println ("-----------------------"); - $ //Exercise: Boolean endsWith (String str): Determines whether a string ends with a specified string. $ - //boolean isEmpty (): Determines whether the string is empty. -System.out.println ("IsEmpty:" +s1.isempty ()); the -String S4 = "";WuyiString S5 =NULL; t

2x3=6 2x4=8 2x5=10 2x6=12 2x7=14 2x8=16 2x9=183x1=3 3x2=6 3x3=9 3x4=12 3x5=15 3x6=18 3x7=21 3x8=24 3x9=274x1=4 4x2=8 4x3=12 4x4=16 4x5=20 4x6=24 4x7=28 4x8=32 4x9=365x1=5 5x2=10 5x3=15 5x4=20 5x5=25 5x6=30 5x7=35 5x8=40 5x9=456x1=6 6x2=12 6x3=18 6x4=24 6x5=30 6x6=36 6x7=42 6x8=48 6x9=547x1=7 7x2=14 7x3=21 7x4=28 7x5=35 7x6=42 7x7=49 7x8=56 7x9=638x1=8 8x2=16 8x3=24 8x4=32 8x5=40 8x6=48 8x7=56 8x8=64 8x9=729x1=9 9x2=18 9x3=27 9x4=36 9x5=45 9x6=54 9x7=63 9x8=72 9x9=813. Output graphics Packagetes

(); - //System.out.println ("Age is:" + i); - - //ot.setobj (New String ("Brigitte")); + // //classcastexception - //Integer II = (integer) ot.getobj (); + //System.out.println ("name is:" + II); A atSystem.out.println ("-------------"); - -objecttoolNewObjecttool(); - //ot.setobj (new Integer);//This is the time to compile . -Ot.setobj (NewString ("Brigitte")); -String s =ot.getobj (); inSystem.out.println ("name is:" +s); - toObjecttoolNewOb

(system.in); theSystem.out.println ("Please enter the" + x + "Student's name:"); +String name =sc.nextline (); -System.out.println ("Please enter the" + x + "Student's language score:"); $String chinesestring =sc.nextline (); $System.out.println ("Please enter" + x + "Student's math Score:"); -String mathstring =sc.nextline (); -System.out.println ("Please enter the" + x + "student's English Score:"); theString englishstring =sc.nextline (); - Wuyi //encapsulate data into student ob

parameter append is True, indicating append, and false to no appendThe code is as follows:1 PackageCom.himi.fileoutputstream;2 3 ImportJava.io.FileOutputStream;4 Importjava.io.IOException;5 6 7 /**8 * How to implement data append write? 9 * Using construction Method: FileOutputStream (String name, Boolean append)Ten * The parameter append is True, indicating append, and false to not append One */ A - - Public classFileOutputStreamDemo5 { the - Public Static voidMain (string[] args)th

1. Create a byte output stream object and do a few things:(1) Call system function to create file(2) Create Fos object(3) Point the Fos object to this file2. code example:1 PackageCom.himi.fileoutputstream;2 3 ImportJava.io.File;4 Importjava.io.FileNotFoundException;5 ImportJava.io.FileOutputStream;6 Importjava.io.IOException;7 8 /*9 * Create file Fos.txt, write string: Hello WorldTen * One * Operation flow of the output of the byte stream: A * A: Create byte output stream object - * B: Write

>100 | | score) {6 Throw NewMyException ("your input score cannot be greater than 100 or less than 0");//Here the MyException is inherited from exception is the compile-time exception, must be handled, here on the throw 7}Else {8System.out.println ("The score you entered is not a problem");9 }Ten } One A}(3) in compiling a test class, test the logic run, as follows:1 Packagecom.himi.myexception;2 3 ImportJava.util.Scanner;4 5 Public classStudentdemo {6 7 Public St

servlet only with Tomcat.(6) Apache is the most beginning page parsing service, Tomcat is developed after, in essence, the function of Tomcat can completely replace Apache, but Apache is the predecessor of Tomcat, and there are many people in the market still using Apache, So Apache will continue to exist, will not be replaced,Apache can not parse Java things, but parsing HTML fast .4. Examples of both:Apache is a car, which can be loaded with things such as HTML, but not water, to fill the wat