Professionals are expected to connect to the Internet in the next two to five years, which will cause the user to use these devices to generate fundamental changes. Users can easily deliver web content, corporate data, and personal data whenever, where and where to use. In order to meet the increasing demand of these information equipment, Sun launched J2ME, QUALCOMM, launched Brew, two new online wireless applications.
Brew
BREW is the abbreviation of Binary Runtime Environment for Wireless, which is a general content provided by QUALCOMM development and execution of wireless data applications. The OEM can launch new devices faster due to fewer internal application development and integration tasks. Users can choose and download wireless software that suits you. In this way, users will promote the development of new wireless data applications and service markets.
The BREW runtime environment is a thinner software interface layer that is located on the wireless device between the chip system software and the application, allowing the end user to download the program wirelessly and run on the device enabled by BREW. BREW has higher flash memory and RAM efficiency - it takes less flash memory, and is dynamically allocated to RAM when the application is running.
1, BREW application platform
The complete BREW solution begins with an open, standard application execution platform on the wireless device.
(1) Skinny - BREW is not only a reduction version of the product developed by PC or PDA, which is much smaller than other application platforms or mature operating systems. Qualcomm is a wireless company that understands the needs of the wireless industry and designing the BREW platform from the chip.
(2) The fast-BREW platform is located on the chip system software, enabling fast C / C local applications, as well as browser and Java-based technology and extension of virtual machines (such as game engine and music player) integrated.
(3) Open - In addition to local C / C , BREW also supports several other languages, including Java, Extensible Identity Language (XML), Flash, etc. Enforcement Environment. Moreover, since it can reside on a smart phone such as a mobile operating system (OS) such as Palm, the BREW Publish System (BDS) wirelessly can be used as an application written for these OS and makes it like a BREW application. Commercialization.
(4) Scalable - Third parties can write extensions to the BREW platform to provide additional functions to the application. QUALCOMM ensures that BREW remains open by issuing an extension and use it to the development group.
(5) Cost-effective - Reduce development costs and shorten the product development time of equipment manufacturers. Equipment manufacturers can take less time in developing applications and equipped with applications for different models, while putting more time into product design.
(6) Security - BREW provides protection for basic phones and wireless networks.
2, BREW transplant package
The BREW platform is committed to the development and manufacture of products and services, and its core is BREW portable package. It shortens the process of integrating the BREW platform into the new developed device.
3, BREW SDK (software development package)
BREW SDK allows developers to work in a familiar environment using standard tools. That is, it is possible to prepare the application used in BREW-based devices without knowing the source code of the chip system and the device manufacturer without direct relationships.
4, BREW Publishing System (BDS)
BDS enables operators to easily put applications from developers to the market and coordinate settlement and payment.
Operators can adjust BDS as needed, including management of their own applications, and select third-party management applications, or choose Qualcomm through operator and developer trade management applications and operators and developer terms.
5, application type
The BREW user can define the handheld device only at the desired application. Users only need to press several buttons to choose from many applications. Communication - Instant messaging, email, ringtone and other interactive messaging
Positioning - mapping, browsing, transportation, and other specific positioning content
Efficiency Tool - Mobile Synchronization Office Application and Utility, Improved Personal Efficiency
Games - Interactive Games between individual players and multiple players
Moving business - account balance, retail, stock trading and other financial transactions.
Entertainment - music, video, humor, and even track a certain event
Information - Flight Tracking, News, Weather, Sports and Other Daily Information
Expansion - Developers can extend third-party extensions in the powerful BREW platform used in applications
BREW offers a set of embedded features API, a highly integrated chipset function, system software, and plug-in for advanced Internet features and multimedia functions for high-grade Internet features, and plug-ins for achieving advanced Internet features and multimedia features. If necessary, the BREW environment can also extend consisting of the manufacturer or other developer at any time to provide additional features that the application can use. This allows powerful small local applications to access local processing and storage, giving client / server solutions than having better performance and functionality than only browser-based structures.
J2ME
J2ME is an abbreviation for Java 2 Micro Edition. It is the best for Sun to apply Java to mobile communication devices, embedded devices, or consumer electrical appliances, is committed to consumer products and embedded equipment. solution. J2ME follows the basic principles of "a single development system for a single development system in a variety of different devices. So J2ME first distinguish between all embedded devices into two types: one is a embedded device with limited computing function, and the power supply is also limited, and the other is PDA, mobile phone); the other is relatively better, and Relatively relatively sufficient embedded devices in power supply (in all ways, refrigerator, TV box (SET-TOP BOX)). Because of these two distresses, Java introduced a concept called Configuration, then limited the above operations, and the embedded device with limited power is defined in the Connected Limited Device Configuration (CLDC) specification; and another device is specified as Connected Device Configuration (CDC) specification. That is, J2ME first uses all of the embedded devices into two abstract types using the concept of Configuration.
1, first knowledge J2ME
J2ME comes from a traditional computer system, which is mainly for the consumer electrical appliance. Java established three levels on the original operating system to achieve modularization and removal. They are Java VM, Configuration (Configuration), and Profile from the bottom to the upper, respectively. VM is responsible for compiling Java Byte Code specification, running on the software of the host operating system, simulating the special software of the Java computer. Configuration is a specification that specifies the VM feature and the Java core library, which uses the smallest class library to achieve simple VM features. Profile is based on Configuration specifications, providing additional class libraries, stipulating advanced features, responsible for establishing a high-level library. The frame is implemented based on a specific configuration layer.
2, J2ME core
The core characteristics of J2ME are KVM. At the VM layer, Sun first implements KVM, which means that the memory requirements at runtime are only calculated in KB. KVM itself requires only 40kb ~ 80kb memory. At the same time, it has a relatively high portability, adapted for 16 or 32-bit RISC / CISC platforms. In the Configuration layer, J2ME specifies the two configurations of CDC (Connected Device Configuration, Connected Device Configuration) and CLDC (Connected Limited Device Configuration, Connected Limited Device Configuration), where CDC requirements are 512KB ROM, 256KB RAM , Broadband network and use TCP / IP protocol, which uses VMs are standard VM (JVM), and the corresponding PROFILE includes Personal Profile, Car Profile and TV Profile, mainly to visual calls (Internet Screen Phone Reference Forum), Digital TV (Digital video Broadcasting), car navigation system and entertainment products. The requirements of CLDC are 128kb ~ 512KB memory, and the ratio of RAM and ROM can be adjusted as needed; a limited energy supply method (such as a battery) can be taken; the narrowband network can not be required to support TCP / IP protocols. It uses the VM to simplify the version and cannot directly use the standard JVM. CLDC Corresponding PROFILE includes MID Profile, PDA Profile, and POS / EFT Profile. In contrast, it applies to equipment with two-way networks but hardware resources, such as mobile phones, handheld computers, etc. In the Profile layer, J2ME specifies the MIDP (Mobile Information Device Profile, mobile information device framework), which is suitable for mobile digital devices such as mobile phones, pagers, PDAs. 3, the advantage of J2ME
Traditional mobile phone software can only provide the most basic speech and short message functions. Subsequent software has added simple additional applications, such as phone book and ringtone editing, etc. With the development of the Internet, the mobile phone is not willing, and the function of accessing the Internet in WAP is joined. User users can easily access wirelessly through mobile phones. Developed to this stage, mobile phone manufacturers have encountered two problems: First, the software development cycle is too long. Due to the lack of open unified programming platforms, the transplantation of the program will not talk, manufacturers need to write procedures for each platform, which will undoubtedly spend time and human material resources. And due to various problems, third-party developers are difficult to intervene and affect the expansion of this market. Another problem is that the browser mode is limited, and the existing WAP function cannot access the Internet directly. The Internet needs to filter through the gateway, and can only access the WML instead of the mainstream HTML, and complex format and graphics cannot be displayed. Use the online trading to increase the server load, slower speed and security can not be worried. In addition, you cannot access the local storage area is also a fatal injury of WAP functionality.
The emergence of J2ME makes the above problems. Because Java language is running across platforms, this feature is eliminating the troubles of developing corresponding procedures on various platforms. Third-party software developers can easily intervene in developing applications, and the development cycle is greatly shortened, but also Support for the dynamic download and upgrade of the application. J2ME provides an HTTP advanced Internet protocol that allows mobile phones to access all information in the Client / Server mode directly accessible, different client access to different files, and access to local storage, providing the highest efficiency online transaction. For mobile device vendors, it is undoubtedly a "cross-platform programming tool, while J2ME's horizontal air is coming to this trend. 4, J2ME application
In addition to better improving mobile phone existing applications, J2ME provides many enhancements such as dictionary, books, games, remote control home appliances and timed reminders, and access to email, instant messaging, stock and electronic maps. .
Currently, connectable private intelligent information devices are playing more and more important roles in our work and life. These products (including cell phones, two-way paging, personal organization, video telephones, and POS terminals) have a lot of common. Sun attempts to expand the use of Java technology by introducing J2ME technology. This multi-function Java application development platform can develop many new features powerful information products. Java technology allows users, service providers, and equipment manufacturers through physical (wired) connection or wireless connection, and use rich applications at any time.
