what is api in java

Click to enter _ more _java thousand ask 1, is-a,has-a,like-a is what In the field of object-oriented design, there are several kinds of design ideas, mainly in the following three kinds:Is-a, Has-a, like-aThere are many embodiments of Java in classes, interfaces, and abstract classes.Learn

To do express information display, such as the order has been shipped, where the goods, such information shows, how to call The courier company's API? Want to use Shun Fung Express, look at the development manual is very complex, read and understand, who knows how to use? Reply content: To do express information display, such as the order has been shipped, where the goods, such information shows, how t

What is the relationship between AWT and swing in java The AWT is an abbreviation for the abstract window ToolKit, an Abstraction Windows Toolkit, which provides a set of interfaces that interact with the local graphical interface. There is a one by one correspondence bet

Original: http://docs.oracle.com/javaee/7/tutorial/doc/overview008.htmTranslation: Shi Zholin [email protected]1.8 Java EE 7 APIs in the Java Platform, standard Edition 7Several APIs that is required by the Java EE 7 platform is included in the

parent class, when the methods are invoked, they must be using the methods defined in the subclass (dynamic connection, dynamic invocation). Polymorphism is divided into compile-time polymorphism and Run-time polymorphism. In which the polymorphic is static, mainly refers to the method of overloading, it is based on the different parameters of the list of differ

Entity classes are a concept that is widely used in Java software development. But there is little on the web to tell exactly what it is. In this issue I am going to talk about what is

In the Java language, in addition to the basic data types, the others are object references to various types of objects, and in Java the references are divided into 4 classes based on the length of their life cycles.1 Strong referencesFeatures: Our usual typical code object obj = obj in new object () is a strong reference. The reference that

false because it differs from the address of the S3. S3 and "Hello" + "world" For comparison, "Hello" + "world" first stitching into "HelloWorld", and then go to the string constant pool to find whether there is "HelloWorld", there is, so and s3 a string object is shared, true. Summarize string s = new string ("Hello") creates a 2 (1) obj

) {MapNewHashmap(); Premiumphone.put ("Apple", "IPhone"); Premiumphone.put ("HTC", "HTC One"); Premiumphone.put ("Samsung", "S5"); Iterator Iterator=Premiumphone.keyset (). iterator (); while(Iterator.hasnext ()) {System.out.println (Premiumphone.get (Iterator.next ())); Premiumphone.put ("Sony", "Xperia Z"); } } }"Main" java.util.ConcurrentModificationException at java.util.hashmap$hashiterator.nextentry (Unknown SOURCE) at Java.util.hashmap$keyiterator.next (Unknow

All say that programmers pay a high salary, as a Java developer programmer, get 20,000 of the salary, what technology needs, the new programmer how to achieve a monthly salary of 20,000. In general, Java programmers with a monthly salary of 20,000 belong to intermediate programmers. It's just that the technology is a

The current technical CTP system provides the version of the API version C++SWIGis a C/C++ tool that can be used to convert interfaces to other languages, which can now be supported Python,Java,R .This article introduces the use of the Swig tool to convert the CTP C + + interface API into a Java callable interface unde

What is the difference between return and return null in Java?The biggest difference:ReturnThe return value of the method must be void!return null;The return value of the method must not be the original data type (the wrapper class has been removed) and the void!Return is the way to jump out ...Return null also jumps o

When we do development, often have the URI and URL confused problem, if at that time directly look at the URI and URL source code can not be confused. First I summarize the relationship between URI and URL: Their relationship is: The URL is a special URI, is the URI including the URL,What exactly

industry with more frameworks: Dubbo, Zookeeper, Netty, Mycat and so on.That's what I thought for the moment. In fact, more should write their own projects, such as writing a more complete personal blog, in the process, encounter problems try to search the current more popular technology to solve, so you will learn faster than light reading.Talk about the front-end, in fact, the current domestic front-end is