[curriculum] Baidu Library Based on Java language and OOP started learning notes

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A history and origin of the Java.

Formerly known as Oak, for the development of embedded system design, the grammar is consistent with C/C++

Two Java language features.

Java consists of four components: the Java programming language, Java file format, the Java virtual machine and Java application program interface(Java API).

The main points:

1, Java inherits the core C++ object oriented language, is a pure object oriented language.

2, Java abandon pointer, operator overloading, increase the garbage collection mechanism, automatic allocation and management of memory

With the C, C++ the main difference

1, Automatic memory allocation recovery, memory management function or operator malloc C/C++ (), realloc (), free () function, the new.delete operator

2, Global variables do not support outside the class, pure object-oriented, all based on class construction, completed in class about operation.

3, The goto statement is not supported, but goto as Java reserved words, no header files

4, Java is an interpreted language, compiled into class bytecode, interpreted in a virtual machine, C/C++ is a compiled language

5, More portable, type the number of bytes are the same in different systems, C++ are different according to the machine definition.

JAVABasic data types the number is the number of bytes?

Byte 1 bytes

Short 2 bytes

Char 2 bytes

Int 4 bytes

Long 8 bytes

Float 4 bytes

Double 8 bytes

Java byte order

J2EERelated technical indicators:

1.JDBC(Java Database Connectivity)To provide a unified interface to connect all kinds of relation database, as the data source, which can provide a unified access to multiple relational database, which consists of a set of Java language classes and interfaces. The tool JDBC / database developers to provide a standard API, which can build tools and interfaces to more advanced, make the database developers can use pure Java API database application programming, at the same time, JDBC is a brand name.

2.EJB(Enterprise JavaBeans)Allows developers to easily create, component based enterprise application deployment and management of cross platform. In Java technology, concern and JavaBeans, it is the component architecture is an open standard, it is platform independent, but the use of Java language. A JavaBean is a class Java JavaBeans specification, usually defines a real-world object or concept. The main features of a JavaBean including the properties, methods and events. Usually, in JavaBeans development environment to a support (such as Sun Java Studio and IBM VisualAge for Java), you can visually operate JavaBean, JavaBean can also be used to construct new JavaBean. JavaBean is also the advantage of Java's portability. EJB (Enterprise JavaBeans) The JavaBean concept is extended to Java server-side component architecture, application of this model to support the multi-layer distributed object. In addition to JavaBeans, the typical component architecture and DCOM and CORBA,

3.Java RMI(Java Remote Method Invocation)For the development of distributed Java applications. A method on a Java object can be a remote Java virtual machine called. In this way, remote method activation can occur in peer to peer at both ends, can also occur between the client and the server, as long as the application of both parties is written in Java.

4.Java IDL(Java Interface Definition Language) Supplied with CORBA (Common Object Request Broker Architecture) of the seamless interoperability. This makes the Java business information resources integration of heterogeneous.

5.JNDI(Java Naming and Directory Interface)To provide seamless connection from the Java to the unified platform. The interface screen use enterprise network naming and directory services.

6.JMAPI(Java Management API)For the system in heterogeneous networks, providing a rich set of objects and method to develop network and service management.

7.JMS(Java Message Service)To provide enterprise messaging services, such as reliable message queue, publish and subscribe communication, as well as the push and pull (Push/Pull) aspects of Technology.

8.JTS(Java transaction Service)Provide open standard access transaction processing resources, such transaction processing resources include transaction processing applications, transaction management and monitoring.

9.JMF(Java Media Framework API), She can help the developers to audio, video and other time based media within the Java application or applet small program, provides the capture, playback for multimedia developers, coding and decoding tool, is a flexible, cross platform multimedia solutions.

10.Annotation(Java Annotation), With the release of JDK1.5 (tiger) in adding new features called Annotation. Annotation provides a mechanism, the program elements such as: classes, methods, properties, parameters, local variables, link packet and metadata. So that the compiler can add metadata stored in the Class file. This virtual machine and other objects can be based on these metadata to decide how to use these program elements or change their behavior. Spring has its own notes, they have different comment style. 11.JavaFX Sun has just released the official version of JavaFX technology, it allows you to use JavaFX programming language to develop rich Internet applications(RIA). JavaFX Script programming language (hereinafter referred to as JavaFX) is a declarative Sun micro system development, staticallytyped (static type declarations of script language,). The JavaFX technology has good prospects, including the ability to directly call Java API. Because JavaFXScript is a static type, it has the same structured code, reusability and encapsulation, such as package, class, inheritance and compiling and publishing unit separately, these characteristics make the use of Java technology to create and manage large programs possible.

12.JMX(Java Management Extensions, Java management extensions) is an application framework, equipment, system management functions such as implantation. JMX can across a range of heterogeneous operating system platform, system architecture and network transmission protocol, flexible development seamlessly integrated system, network and service management application.

13.JPA(Java Persistence API),JPA through JDK 5 annotations or XML to describe the mapping relationship between object relational tables, and the running time of the entity object persistence to the database.

14.JSP(Java Server Pages)Is initiated by Sun Microsystems, many companies involved in a dynamic webpage technology standards established. JSP is similar to ASP technology, it is in the traditional webpage HTML files (*.htm, *.html) inserted in the Java segment (Scriptlet) and JSP marker (tag), thus JSP documents (*.jsp). Using Web development of the JSP application is cross platform, which can run under Linux, can also run on other operating system.

The installation of JDK and JAVA_HOME and Path configuration, these are the basis of comparison of the data, if we use the higher version of JDK and eclipse, many environmental variables and path are set not in need.

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Posted by Chester at November 19, 2013 - 4:00 AM