java code analysis tools

found that the problem should be String.charat () above, the code is as follows:public char charAt (int index) { if (Index There are two judgments that are very time-consuming, and we change to the following codeif (strs.length==0) return ""; String prefix =strs[0];for (int i = 1;ibecomes the 2ms, sure enough the problem is here, if we do not use the ToCharArray () method should be 1ms, which shows that our ideas and algorith

returns the computed Hashcode value:1 public class comhashcode{2 public static void Main (string[] args) throws Exception {3 Comhashcode a = new Comh Ashcode (); 4 Comhashcode B = new Comhashcode (); 5 System.out.println (A.hashcode ()); 870919696 6 System.out.println (B.hashcode ()); 298792720 7 8 Long num1 = new Long (8), 9 long num2 = new Long (8), System.out.println (Num1.hashcode ( )); 811 System.out.prin

! = Null) {Object obj2 = sockinputstream; if (j 2) = 2) obj2 = new GZIPInputStream (java. io. inputStream) (obj2); if (classLoader = null) obj1 = transCoder. decode (java. io. inputStream) (obj2); else obj1 = (ObjectTransCoder) transCoder ). decode (java. io. inputStream) (obj2), classLoader);} sockinputstream. willRead (2147483647); sockinputstream. getLine ();

with ArrayList.(This is excerpted from the JDK 6.0 API).Ii. Source Code Analysis 2.1, definitionFirst we look at the definition of LinkedList: Public class Linkedlistextends abstractsequentiallistimplements ListFrom this code we can clearly see LinkedList inherit abstractsequentiallist, implement list, Deque, cloneable, Serializable. Abstractsequentiallist provi

classcomhashcode{2 Public Static voidMain (string[] args)throwsException {3Comhashcode A =NewComhashcode ();4Comhashcode B =NewComhashcode ();5System.out.println (A.hashcode ());//8709196966System.out.println (B.hashcode ());//2987927207 8Long NUM1 =NewLong (8);9Long num2 =NewLong (8);TenSystem.out.println (Num1.hashcode ());//8 OneSystem.out.println (Num2.hashcode ());//8 A } -}Summarize:(1) binding. when the Equals method is overridden, it is often necessary to override the

The CAS algorithm is mentioned several times in this paper, and a simple description of CAs (non-blocking algorithm) is first described. CAS has 3 operands, memory value V, old expected value A, new value B to modify. If and only if the expected value A and memory value v are the same, the memory value V is modified to B, otherwise nothing is done.Concurrentlinkedqueue is a thread-safe queue. He uses a non-blocking algorithm (CAS) to implement thread-safe. Concurrentlinkedqueue is a line-free se

); } }CopyonwritearraylistCopyonwritearraylist is a tool class in Java and contracted, and is introduced in jdk1.5, and its content is sufficient to write an article, so it is no longer open. Just a brief description of it.Its basic idea can be seen from the name, when the writing operation. A copy is copied and the write is made to the copy.The read and traverse operations occur on the replica that exists at the moment the operation occurs.

Java HashMap implementation principle source code analysis, javahashmap HashMap is implemented based on the Map interface of the hash table. It provides all the optional ing operations and allows creation of null values and null values. It is not synchronized and the ing sequence is not guaranteed. Next we will record the implementation principles of HashMap. Has

. Construct a new, empty tree map using the natural order of the keys Public TreeMap () { comparator = null; } 2. Construct a new, empty tree map that is sorted according to the given comparer public TreeMap (comparator3, TreeMap Common methods　　V put (K key,v value): Adds a key-value pair (Key,value) to the TreeMapPublic V put (K key, V value) {entry　　set: Returns the Set view of the mappings contained in this mapPublic set　　boolean remove (Object o): If there is a mappin

deleted. If there are no elements in the collection, NULL is returnedPollfirst (); Polllast (); Gets the element, but the element is deleted. If there are no elements in the collection, NULL is returned Public class Linkedlistdemo { publicstaticvoid main (string[] args) { New LinkedList (); Link.add ("JAVA01"); Link.add ("JAVA02"); Link.add ("java03"); Link.add ("java04"); while (! Link.isempty ()) { System.out.println ((Link.

learning, artificial intelligence, data mining, data analysis. Languages include: Java, Scala, Python, Shell, Linux, and more. It also covers the usual use of mobile phones, computers and the Internet using tips, problems and practical software. As long as you focus and stay in the group, every day must have a harvestcorresponding to the platform discussion and answer QQ group: Big Data and artificial int

) { g.drawimage (bg, 0, 0, null); Sun.draw (g); Earth.draw (g); Mars.draw (g); } public static void Main (string[] args) { new Solarframe (). Launchframe (); } Star.java Package solar; Import Java.awt.Graphics; Import Java.awt.Image; Import util. Gameutil; public class Star {public Image img; public double x,y; int w,h; public void Draw (Graphics g) { G.drawimage (img, (int) x, (int) y, null); Public Star (

What is FindBugs? FindBugs is a static analysis tool that finds bugs in Java programs . It compares the bytecode to a set of defect patterns by examining the class or jar file to identify possible problems. With the static analysis tool, you can analyze the software without actually running the program, and find some potential hidden problems that are hard t

Java Collection of dry goods-inventory list source code analysis, dry goods inventory listPreface In the previous article, we analyzed ArrayList in detail. Today we will talk about 'arraylist. What is the difference between them? The biggest difference is that the underlying data structure is implemented differently. ArrayList is implemented by arrays (see the pr

Java Solar System Small game analysis and source code-20150809Recently looked at some object-oriented knowledge, and then followed the teacher's explanation to do a solar system of the planets around the sun to the game, to practice consolidating the knowledge of recent studies:Knowledge points: Inheritance of classes, overloading and rewriting of methods, polymo

Java Solar System Small game analysis and source code-20150809Recently looked at some object-oriented knowledge. Then follow the teacher's commentary made a solar system of the planets around the sun to the game, to practice consolidating the knowledge of recent studies:Knowledge points: Inheritance of classes, overloading and rewriting of methods, polymorphism,

1. IntroductionList in the data structure is expressed as a linear table, its elements are stored in a linear manner, the collection allows to store duplicate objects, list interface main implementation classes have ArrayList and linkedlist. Java provides the implementation of these two structures, this article is to be familiar with the next ArrayList of the source code implementation. Examples of use are:

the Noclassdeffounderror is reported.another way to specify a classpath:The class bytecode file is made into a jar package and placed in the lib/ext/directory of the JRE so that it can be found directly at execution time without the need to specify CLASSPATH.Class Loaders and ClasspathFrom the previous article we learned that the ClassLoader uses three by default:1,bootstrap ClassLoader, starting the ClassLoader, is responsible for loading the core class (that is, the class at the beginning of

. * * If current capacity are maximum_capacity, this method does isn't * resize the map, but sets threshold to Integer. Max_value. * This have the effect of preventing future calls. * * @param newcapacity The new capacity, must be a power of; * Must be greater than current capacity unless current * capacity are maximum_capacity (in which case Val UE * is irrelevant). */void Resize (int newcapacity) {entry[] oldtable = table; int oldcapacity = Oldtable.length;

don't need to modify it in general.HashMap is a data structure that supports fast access, and it is important to understand its data structure in order to understand its performance.Third, data structureWe know that the two most commonly used structures in Java are arrays and analog pointers (references), and almost all data structures can be combined using both, HashMap. In fact, HashMap is a "chain table hash", which is the following data structure