learn java hard way

value of 0.5if// Table more than half empty. . Map.resizetable (_isshared); 03.} Then look at the put function, the more striking is the index and the slot is obtained, is completely used hashkey displacement method obtained, so that the index and avoid collisions.01.Private FinalObject put (object key, object value,intKeyhash,02.BooleanConcurrentBooleanNoreplace,Booleanreturnentry) { 03.FinalFastmap map =Getsubmap (Keyhash); 04.Finalentry[] entries = map._entries;//Atomic. 05.Final i

common classes of implementations that are possible: the Arrarylist class and the vector class Arrarylist class are introduced in JDK1.2, using asynchronous processing, high performance, and non-thread-safe. Vector class is introduced in JDK1.0, the use of synchronous processing, low performance, belonging to the thread-safe.(2) Set interface:Can not repeat the content, but can be sorted, break into the order of its two commonly used subclasses: HashSet class and TreeSet class HashSet class is

An optional chained call (Optional Chaining) is a way to request and invoke properties, methods, and subscripts on an optional value that the current value may be nil. If the optional value has a value, the call succeeds, and if the optional value is nil, the call returns nil. Multiple calls can be joined together to form a chain of calls, and if any one of the nodes is nil, the entire call chain will fail, returning nil.Swift This function design is

usually do a project to build a lot of attribute class, method class and view class, after learning the IO stream to think of a way, is to write a string of code, and then write in the text document class txt text document that has only class First of all, generate this code for the attribute class:Package Com.jereh.generate;import Java.io.*;import java.util.*;p ublic class Generate1 {/** * @param args */public static V OID Main (string[] args) {File

in) throws Exception {int len = 0; in = new Bufferedinputstream (in); StringBuffer buffer = new StringBuffer (); while (len = In.read ())!=-1) {buffer.append ((char) len); return buffer.tostring (); } } 5. Modify Index.jsp 6, the preparation of basefile.jsp documents Notice the code in the basefile.jsp, no you can refer here /**************************************************************************************/ 7, to be completed here, it is necess

Http://developer.51cto.com/art/201512/502926.htm Unlike your problem, I think software engineering is mainly used to solve problems. Some bloggers think that "every child should learn to program", "You think learning math is just fun." If you have seen my HTML5 debugger, you will find that I am a programmer, but I do more work than math. Both agree on the idea that software engineering is not just a few words written in computer language. The softwar

previous step of the filter return to the front end, that is, in [Chain.dofilter (Request, Response)][system.out.println ("After ...")] executed between them.The 3.SpringMVC mechanism is to distribute requests to different controllers by the same servlet, in fact this step is performed in the servlet's service () method. So the filter, Interceptor, Service () method, the execution order of the DISPATC () method should be like this, roughly draw a picture: Actually very good test, write a filter

methods.　　② down transformation and runtime type recognitionAs the upward transformation loses the specific type information, we think that by going down the transformation should be able to get type information, in the Java language, all transformations will be checked. If the type does not match, a classcastexceptionis returned. This behavior of checking the type during run is called Runtime type recognition (RTTI).5. Summary Polymorphism means "di

Follow the examples to learn java multithreading 6-how to correctly publish thread-safe objects, java6- Everything we mentioned above is only for the purpose of correctly releasing a thread-safe object. I. Closed threads This is easy to understand. If a variable changes its status in a thread, the variable must be thread-safe. We often use stack closures and ThreadLocal classes. There is a virtual machine s

1, more hands Learning programming languages is not only a theoretical study, but also the use of this language to serve your thoughts. It is important to understand this language, but to reach the point of understanding, mastery must be done, more time, more examples. Computer science is a practice-oriented discipline, successful software developers are all through a lot of physical training, only the combination of theory and practice can really master only and skills. 2. Multi-Brain For th

1.About Java coercion Type conversionsint x = 1;Byte y = 2;byte z = 0;1). z = (byte) (x+y);//forced type conversion succeeded2). z = (byte) x+y;//forced type conversion error, loss accuracyThe second way to convert X to byte is to give an error.Resolution: Byte short int is an int after each other, including Byte+byte,short+short, if the three and long types are mutually counted as long typesView the

Nine, interfaceInterfaces and internal classes provide us with a more structured approach to separating interfaces from implementations.1. Abstract classes and abstract methodsAbstract classes are a kind of moderation between common classes and interfaces. Creating an abstract class is what you want to manipulate a series of classes through this generic interface. Java provides a mechanism called an abstract method , which is incomplete, with only de

1. Why Use NiONIO was created to enable Java programmers to implement high-speed I/O without having to write custom native code. NIO transfers the most time-consuming I/O operations (that is, the fill and fetch buffers) back to the operating system, which can greatly improve speed. The most important difference between the original I/O library (in java.io.*) and NIO is the way data is packaged and transmitt

Java has been learning for some time, and found that it is only to understand Java, but also outside the threshold.Sometimes it really feels like this is not an alien language, various methods of various kinds of excuses, always silly confused. Learned the knowledge after one weeks began to blur, sometimes sleep at midnight when still thinking, feel that they are almost schizophrenic, full brain in the chil

Generics are a new feature of Java SE 1.5, and the nature of generics is a parameterized type, meaning that the data type being manipulated is specified as a parameter. This type of parameter can be used in the creation of classes, interfaces, and methods, called generic classes, generic interfaces, and generic methods, respectively. the benefits of introducing generics into the Java language are simple and

Generics are a new feature of Java SE 1.5, and the nature of generics is a parameterized type, meaning that the data type being manipulated is specified as a parameter. This type of parameter can be used in the creation of classes, interfaces, and methods, called generic classes, generic interfaces, and generic methods, respectively. the benefits of introducing generics into the Java language are simple and

classTest2extendsThread {//overriding the Run method@Override Public voidrun () {//statements that need to be executed concurrentlytest (); } //test Method Public voidTest () { for(inti = 0; I ) {System.out.println ("I =" +i); //controlling threads through thread classes Try { //let the main thread hibernate for 100 millisecondsThread.Sleep (100); } Catch(interruptedexception e) {//TODO Auto-generated catch blockE.printstacktrace (); }

12pageencoding= "UTF-8"%>3456789Ten One A //Check session, get session information -Object obj = Session.getattribute ("username"); - if(obj! =NULL) the { -Out.print ("Welcome login" +obj.tostring ()); - } - Else + { -Out.print ("Session timed out, please log back in to the system"); + //jump to user interface after 3 seconds AResponse.setheader ("Refresh", "3; Url=login.jsp "); at } -%> - Main Page Face - - - in12pageencoding= "UTF-8"%>3456789Ten Login Page One A - //Destroy Session - sessio

) jspgen.com * @created March 2013 * @email [emailprotected] * @a ddress www.jspgen.com */public class SendAction extends Action {/** * default method */@Override P Ublic String Execute () {return ' mail '; /** * Send mail Submission */public String Mail () {Boolean isflag = false; Long time = Dates.gettimemillis (); String to = GetParameter ("to"); Receive form values (form name: to) Isflag = SendMail (To, GetParameter ("subject"), GetParameter ("content"), time)

identifier is a reference. Point to the object inside the heap.Package Com.ray.ch14;public class Test {public static void main (string[] args) {int[] ints = new int[] {1, 2, 3}; System.out.println (INTs);}}Output:[[Email protected]The above output is actually a memory address.6. The underlying type array stores the values of the underlying type. Object arrays are stored as references to objects (memory addresses)Package Com.ray.ch14;public class Test {public static void main (string[] args) {in