1, the field of objects, 4 main areas: 1.1 Basic field basic class: Integer, Boolean and Char, the most basic structure: List, binarytree, set, etc., similar data structure semantic class: Date, Time, Money, etc. 1.2 structure Field Machine Communication Class Database Operation Machine Interface Interface Class 1.3 Business Domain Attribute Class Role Class Interrelationship 1.4 Application Field Event Identification Event Management Class 2, Fields of Class Forms High - level Fields Models in Low-level The model of the class is based on the model. The basis of the reusability of the assertion software, the higher the field, the worse the reusability. 3. About the business sector is very challenging in a field. The general supplier does not have professional experience, developing universal class libraries; such a class is a terrible thing, which means that every purchase person needs to be customized. Does this mean that the reusability of the business sector is denied? of course not. Recently I have some knowledge of ERP. ERP products are a collection of typical business domain class libraries. Mature ERP products, such as SAP, BAAN, Oracle Application have considerable reusability. This strong is only relative, customization is inevitable. Taking into account the cost and difficulties of customization customization, it is not difficult to understand why ERP product implementation is universally persuaded that users accept business processes and management methods customized in the product (indeed necessarily applicable to each business), and try to avoid them The product itself changes. 4. Replace the set by quantitative approach to the basic field class, and the quantitative measurement standard is an attachment. 4.1 Direct class reference set: A class C direct class reference is a class directly referenced; 4. Indirect class reference: Assuming C1, C2, C3, ....., CN, the indirect class reference set of C is the direct class reference set and C1, C2, C3, ......, CN's indirect class reference set. It is obviously a recursive definition. 4.3 A class of direct dependence set refers to the size of the direct class reference set of this class; a class is indirectly attached to the size of this class of indirect class reference sets. The above definition seems to be difficult to understand, in fact, it is not difficult, for example, the C11 F1 C1 C12 F2 C21 F3C C2 C22 F4 C31 × F4 C3 C32 F4 is directly related to C1, C2, C3 = 3, indirectly Collection of all collections, including Fi (4), CI (3), Cij (6) = 134.4 Reel for the collection: The class in the high-level field has a higher indirectly, in the low-level class has more Low indirectly followed. 5, DEMETER Rules: Limitations directly in the guidelines of the assembly.
