Mobile development literacy

Recently, I am very interested in mobile device development, but I am not enough time to solve many problems in the sea. Today, I want to help new users in this field.

First, I want to differentiate the operating system of the mobile device and then talk about the development system.

Mainstream operating systems include: Symbian, smartphone + Pocket PC => Windows Mobile, palmos, and Linux

Symbian focuses on speech applications: Symbian is the leader in this mode. They emphasize the integration of speech functions and data and speech functions. Today, the most popular smart phone in the sales market is based on Symbian. Symbian's authorized license covers a wide variety of devices, such as phones with micro-keyboards, phones with stylus input, and phones with QWERTY keyboards. Nokia, as the leader in the global mobile phone field, is also a powerful driving force for the Symbian platform.

Microsoft and palmsource take general-purpose mobile data applications as the core: The Treo 600 phone PDA produced by palmsource is recognized as the best performance among similar products, it can balance the huge installation load brought by handheld applications, and this feature makes the off-the-shelf that can meet user needs no longer far away. Microsoft, with the powerful and flexible operating environment of its windows mobile OS, provides the most powerful support for enterprises, especially Microsoft-centric. Microsoft OS also has powerful network functions. Microsoft and palmsource have now switched their focus from PDA to the mobile phone market.

Seamless integration of Linux mobile devices and servers: the latest version for Embedded Computing, such as PDA and telephone, is kernel 2.6, a powerful operating system with enhanced real-time performance, and flexible I/O support for microcontroller, as well as big storage features. Although he has almost no market share, it is widely believed that Linux is likely to become a heavyweight role in the future, especially as a hardware platform with powerful computing capabilities. Some vendors have begun to take action: Motorola is one of the only vendors that provide Linux-based smart phones, while zaurus PDA of sharp also uses Linux. On the other hand, Linux has gained more share of the server market, especially the seamless expansion of server data by some Linux mobile devices, and for organizations and ISVs (independent software vendors, independent software vendors) A comfortable development environment. In fact, whether mobile phone manufacturers such as Motorola or Linux providers such as red hat, they will jointly lead the market. For users, in addition to paying close attention to market changes, the number of users who choose Linux as their platform ultimately depends on the applications they want to run, and the existing back-end systems, rather than the advantages of individual technologies.

The development environment includes: j2-kjava, brew, and. net, saving a lot of data. Let's briefly describe the following two aspects:

Two early implementation methods for the Java platform of embedded devices: kjava and personaljava:
If you have been paying attention to Sun's support for resource restriction devices for the past two years, you must be familiar with kjava and personaljava. Personaljava is Sun's first attempt to create a Java platform version for Resource Restriction devices. Sun's spotless Research Plan derives kjava, a Java platform developed by Sun for palm in javaone in 1999.

Both personaljava and kjava develop independently.

Personaljava is gradually becoming a personal profile of CDC.
This profile, which is still in the development stage, will be at the top of the basic profile and will be backward compatible with personaljava 1.1 and 1.2.

The situation of kjava is unclear. Sun is very concerned about the experimental status of kjava and reminds developers to pay attention to its constant changes or even major changes to APIs. Palm Inc. is currently defining a PDA profile for cldc, which will replace kjava. Unfortunately, it is not yet clear how many modifications should be made to the existing kjava application to make it work together with the new archive.