Demonstration of urban intelligent transportation software system based on springboot+android mobile application [with project source code attached]

Demonstration of urban intelligent transportation software system based on Android

Introduction to Java

Java is the general name for the Java object-oriented programming language and Java platform launched by Sun Microsystems in May 1995. It was jointly developed by James Gosling and colleagues and officially launched in 1995. Later, Sun was acquired by Oracle, and Java became an Oracle product.

Java is divided into three systems [5]:

1. JavaSE (J2SE) (Java2 Platform Standard Edition): Java platform standard edition, mainly used for the development of desktop applications, and is also the basis of Java. It includes Java language basics, JDBC (Java Database Connectivity) operations, I/O ( Input/output), network communication, multi-threading technology;
2. JavaEE (J2EE) (Java 2 Platform, Enterprise Edition), Java Platform Enterprise Edition, is mainly used to develop enterprise-level distributed network programs, such as e-commerce websites and ERP (Enterprise Resource Planning) systems. Its core is EJB (Enterprise Java component model);
3. JavaME (J2ME) (Java 2 Platform Micro Edition), a micro version of the Java platform, is mainly used in the development of embedded systems, such as handheld computers, mobile phones and other mobile communication electronic devices. Now most mobile phones produced by mobile phone manufacturers support Java technology.

Main features  of Java

1. Simplicity of the Java language

The syntax of the Java language is very close to the C language and C++ language, making it easy for most programmers to learn and use. On the other hand, Java discards those features of C++ that are rarely used, difficult to understand, and confusing, such as operator overloading, multiple inheritance, and automatic casts. In particular, the Java language does not use pointers, but references. It also provides automatic allocation and recycling of memory space, so that programmers do not have to worry about memory management.

1. Object-oriented nature of the Java language

The Java language provides object-oriented features such as classes, interfaces and inheritance. For the sake of simplicity, it only supports single inheritance between classes, but supports multiple inheritance between interfaces, and supports the implementation mechanism between classes and interfaces (keywords are implements). The Java language fully supports dynamic binding, while the C++ language only uses dynamic binding for virtual functions [6]. In short, the Java language is a pure object-oriented programming language.

1. Distributed characteristics of Java language

The Java language supports the development of Internet applications. Among the basic Java application programming interfaces, there is a network application programming interface (java net), which provides class libraries for network application programming, including URL, URLConnection, Socket, ServerSocket, etc. Java's RMI (Remote Method Activation) mechanism is also an important means of developing distributed applications.

1. Robustness of the Java language

Java's strong typing mechanism, exception handling, automatic garbage collection, etc. are important guarantees for the robustness of Java programs. Discarding pointers is a wise choice by Java. Java's security checking mechanism makes Java more robust.

1. Java language security

Java is usually used in network environments. For this reason, Java provides a security mechanism to prevent malicious code attacks. In addition to the many security features of the Java language, Java has a security prevention mechanism (class ClassLoader) for classes downloaded through the network, such as allocating different name spaces to prevent replacement of local classes with the same name, byte code inspection, and providing security management Mechanism (class SecurityManager) allows Java applications to set up security sentries [7].

1. Java language architecture neutrality

Java programs (files with the suffix java) are compiled on the Java platform into an architecture-neutral bytecode format (files with the suffix class), and can then be run on any system that implements this Java platform. This approach is suitable for heterogeneous network environments and software distribution.

1. Java language portability

This portability comes from architecture neutrality, and Java also strictly regulates the length of each basic data type. The Java system itself is also highly portable. The Java compiler is implemented in Java, and the Java running environment is implemented in ANSI C.

1. Interpreted features of the Java language:

As mentioned before, Java programs are compiled into bytecode format on the Java platform and can then be run on any system that implements the Java platform. At runtime, the Java interpreter in the Java platform interprets and executes these bytecodes, and the classes required during the execution are loaded into the running environment during the connection phase.

1. Java high performance features

Compared with those interpreted high-level scripting languages, Java is indeed high-performance. In fact, with the development of JIT (Just-In-Time) compiler technology, Java's running speed is getting closer and closer to C++.

System page display

If necessary, you can scan the QR code below the article to contact the source code.