java code review template

later4. Constants, variables:There is a lot of data in the program to represent the state of the program, some data will change in the process of operation, there areSome data will not change during the program's operation. These data are called variables and constants, respectively. Variable in theMust be declared before use: Data type variable name variables can be divided into: local variables, member variables, method parameters,Exception handling parameters.Local variables: Variables defin

1. What is the Java method?In our daily life, the method can be understood as the solution to do something and take it.In Java, a method is a way to accomplish something or to implement a function.Method implementation, there are a number of statements that are used to accomplish some meaningful function-usually working with text, controlling input, or calculating values.We can implement (or call) the metho

equals (object) method, then each object in both objects is called hashCodemethod must produce the same integer result, if two objects are not equal according to the equals (object) method, they hashCode do not require unequal calling methods, but for hash tables, the performance is best unequal. Therefore, we'd better rewrite.As mentioned earlier, the String class overrides the Equals () method, but the string class also overrides the Hashcode () method, which is the hashcode () generated from

an exception.------------------------------------------------------Inner classStatic Inner classes: Create classes in classes, static adornments, and only static properties and methods of the perimeter class can be called.member Inner class: A class created in a class that cannot use the static modifier.Anonymous inner class: Creates an object directly in the method.Local inner class: A class that is created in the method body, has no modifiers, and can access only the final decorated constants

class name can be called.After the method is static, it is easy to use, but the class can also be used by other programs to establish objects, in order to be more rigorous, forcing the class cannot establish objects, you can do this by privatizing the constructor .Person p = new person ("Zhangsan", 20);What has been done in this sentence?1. Because new uses Person.class, the Person.class file is first found and loaded into memory.2. Execute the static block of

our own defined Servlet class . 5. Servelt the relationship between core APIs UML diagram:6. The start of the servlet (default is a singleton servlet) (the Init method is executed the first time the servlet is called by default)• The servlet container loads the servlet at the following times:–servlet loading some servlets automatically when the container starts– After the servlet container is started, the customer makes the first request to the servletAfter the –servlet class file is updated,

, or has a default initialization value.Format: variable name of data type = initialization value;Categories of variables in 4.JAVA:A. Data type:Basic data type: Numeric type (integer type: byte/short/int/long; floating-point type: float/double)Character type (char)Boolean Type (Boolean)Reference data types: Classes (Class)/interfaces (interface)/arrays ([])Integer defaults to: int decimal default: DoubleB. Type auto-boost: High end Double/flaot/long Intàbyte/short/char5. Arithmetic operator: +-

Reprint: http://www.ibm.com/developerworks/cn/java/j-lo-velocity1/Velocity is a Java-based template engine that allows anyone to simply use the template language to refer to objects defined by Java code, thus separating the interf

Java Web review Part 6: Servlet thread security, javawebservlet I have mentioned a lot of basic Servlet knowledge before. This article focuses on Servlet thread security issues.1: multi-threaded Servlet Model To understand Servlet thread security, we must first understand how the Servlet instance is created and what its mode is. By default, the Servlet container creates only one Servlet instance for the dec

"); the same as the code in the same sentencePrintWriter writer = Response.getwriter ();Writer.write ("China");C. Using response for file download:String Path = This.getServletContext.getRealPath ("/China. jpg");String fileName = path.substring (path.lastindexof ("\ \"));Response.setheader ("Content-disposition", "Attachment;filename" +urlencode r.encode (filename, "UTF-8"));//Set the response header, Tell the browser that the response is a download r

up execution eligibility.After notify, back to the temporary state, not necessarily run, because not necessarily rob the executive right.Because our thread inherits the thread parent class, we use super to call the parent class constructor method to give the nameSell Tickets:Multithreading shares the same resources, defined as static. Ticket--, 1:2, number 3rd is first printed out as a dual-core CPU, because the callPrinting at the command line is also a program. If not defined as static, ticke

Directory Templates Introduction　　　　　 MyEclipse comes with templates detailed New template Custom Template 　　Because they are more lazy, especially to knock repeated code comparison aversion, so often like to use shortcut keys and templates, MyEclipse template function is actually very powerfu

to access the remote database, you need to modify the section:--For Master (this refers to the host that created the database)A. Modifying the/etc/postgresql/9.4/main/postgresql.confOriginal content:# listen_addresses = ' localhost ' after modification ( Remove the # comment):listen_addresses = ' * ' #监听来自所有ip的访问数据库请求B. Modifying/etc/postgresql/9.4/main/pg_hba.conf (hba=host-based authentication)# IPv4 Local connections:host all 127.0.0.1/32#新增内容, you can add several IP segments tha

Object-oriented three main features: encapsulation, inheritance, polymorphismClass: The blueprint of an object, the template that generates the object, is a description of a class of things, an abstract conceptual definition object: The actual existence of each individual of such a thing, also known as an instance class between three relationships: dependency (uses-a), aggregation relationship (has-a), inheritance relationship (IS-A) Object-oriented:

Java class loading takes a full-fledged delegation mechanism, and the subclass will delegate to the parent class when the class is loaded by default, but the subclass will attempt to load the class itself when the parent class is not loaded. This mechanism can effectively prevent a class from being loaded multiple times, and also to some extent prevent rewriting the JDK's own class "Java itself to restrict

Java web crawler Technology, the discovery of web crawler technology first divided into the following steps:1. Open Web Link2, the page code with a BufferedReader storageHere is a code example that I made:In the process of learning web crawler first to import two packages: Htmllexer.jar,htmlparser.jarpublic static void Main (string[] args) { try { URL url = new

Object-oriented Basic concepts1, object-oriented (OOP, OOD) three major features: encapsulation, inheritance, polymorphism. Note that abstraction is not one of the characteristics2, object-oriented programming is to abstract the data, and functional programming is to abstract the behavior. In the real world, data and behavior coexist, and so do programs, so we have to learn both of these programming ways.3, the concept of the class is an abstract concept, including data and operations on the dat

memory visibility)10. Synchronized modified variable, modified method or code block1) Possessing atomic nature2) have memory visibility3) Heavy-weightSo he can implement the security of the operation between threads!11. Volatile modifier Variables1) no guarantee of atomicity2) have visibility3) Lightweight12, about i++1) First read, read the value of I from main memory update to current working memory2) Next change, add 1 to I3) Last update, refresh

the loopfor (j=i-1;j>0;j--) {if (Array[0]array[j+1]=array[j];//the position of the element smaller than the Sentinel moves backwards}else{Break}}Code Lite version/*for (j=i-1;array[0]ARRAY[J+1]=ARRAY[J];}*/array[j+1]=array[0];//inserts the current element to be compared to the location found}}/*** Output array elements* @param array to display*/static void show (int [] array) {for (int i = 1; I System.out.print (array[i]+ "");}System.out.println ("\

isDescribes the exceptions that the program catches, such as classnotfoundexception. The error class is used to indicate a reasonable application but becauseJVM errors, such as virtual machine error virtualmachineerror. (the error does not allow the programmer to capture)Custom exceptions can inherit the Throwable class or exception, and do not inherit the error class. And there can be inheritance between custom exceptions.Public to design a work function for a custom exception, construct a cus