Software develops a true goal use code aspect investment， in order to duplicate uses the code in the identical company or in the different company's other developments. In recent years， the programmers invested the massive energy establishment to be possible duplicate to use software. The early time used object-oriented to program the aspect diligently already in programming language in the and so on the Java development the full realization， software may not multi- expenses any work on the movement in each kind of platform.
But， Java certainly is not automatically enables software to be allowed duplicate to use， the Java code writes very much well， makes other development personnel to be very easy to change， but turns round with the software goal is lets the development personnel not need the again compiler to be able to use. In addition， true turning round with is the development personnel continually own code does not need redo translate May code integrates in own design.
When JavaSoft publishes the Java programming language， it has not certainly realized Java the huge influence which will produce to the software development. But along with the Web technology rapid development as well as to the interaction software technology demand growth， JavaSoft started to realize the Java development potential. Thereupon JavaSoft starts to develop some to use in to process the current software development to face the question the Java correlation technology， one kind of technology is the JavaBean technology， this kind of technology is for realize develops to the synthesis software module technology demand. JavaBean is one kind especially for the current software development design brand-new module technology; it has provided one kind of extremely good question solution for the software development.
Compact convenient foundation and use; The JavaBean compact demand is frequently uses in based on the JavaBean module in the distributed computing environment， this causes the JavaBean module frequently to need to carry on the transmission under the limited band width connection environment. Obviously， in order to adapt the transmission efficiency and the speed， the JavaBean module must be more compact is better. Moreover， for well the foundation and the use module， should simply cause its Viet Nam to be better. Usually in order to enhance the module the simplicity and compact， the design process needs to invest the relative bigger time. Now had the module software technology usually is use complex API， this frequently does the development in to found time the module is completely muddled. Therefore， the JavaBean module must not only be easy to use， moreover must be advantageous for the development. This says regarding the module development is very important， because this may cause the development not to need to spend the massive times in uses API to carry on in the programming， thus carries on well to the module enhances the module to be possible to watch the nature. The JavaBean module majority was based on already in a traditional Java programming kind of structure which has， this the development which already was allowed skilled to use the Java language regarding these is extremely advantageous. Moreover this may cause the JavaBean module to be more compact， because the Java language has absorbed in the before programming language massive merits in the programming， already caused the procedure which developed to change quite effective.Complete probability; JavaBean the API AND-OPERATION foundation independence unified to the platform Java system， provides has been independent to the platform module solution. Therefore， the module development may not need again for had Java the applet platform unique kind of storehouse to worry. The final result all will be a module which computer sharing may duplicate uses， and in any supports Java in the system not to need to revise the execution.Inherits Java the formidable function; the existing Java structure already provided many kinds of has been easy to apply to the module function. Comparison more importantly Java itself in sets at the kind of discovery function， it may cause the object when the movement each other dynamic correlation， such object may independently comes out from the development system or in its development history. Says regarding JavaBeans， because it is based on the Java language， therefore it speaking of naturally inherited this the count for much function regarding the module technology， but no longer needed any overhead to support it. JavaBeans inherits in the existing Java function also has an important aspect， is the durability， it preserves the object and obtains the object internal condition. The sequence provides which through Java (serialization) the mechanism; the durability may automatically carry on processing by JavaBeans. Certainly，it is needing time， the development also may own establish the durable plan which has custom-made Application procedure structure support; How is the JavaBeans another design goal designs the environment the question and the development uses JavaBeans to found the application procedure. The JavaBeans system structure support assigns the design environment attribute and the editor mechanism in order to JavaBeans module visible edition. The like this development may use the visible application procedure structure seamless to assemble and to revise the JavaBeans module. Likes Windows in the platform visible development kit VBX or OCX controls the processing module to be same. Through this method， the module development may assign in the development environment to use and to operate the module the method.
Distributed computing support; Supports the distributed computing although is not in the JavaBeans system structure core element， but also is in a JavaBeans main question. JavaBeans causes the development to be allowed at any time uses the distributed computing mechanism， but does not use the distributed computing the core to support increases the extra burden for oneself. This is precisely stemming from the JavaBeans module compact consideration， without doubt the distributed computing needs the massive overheads.
JavaBeans and Java although between JavaBeans and Java already had the explicit boundary， but still has the extremely obvious confusion between certain aspect of JavaBeans and Java. Java truly is can the object which founds for the user may entrust with heavy responsibility， but it has not actually managed the rule or the standard which these objects mutually affects. JavaBeans through assigns between the definition object the correlation mechanism， as well as the majority of objects need to support the commonly used behavior， like the durability and actual processing and so on， have established the module model which own needs. Although the current Java module model also may move very much well， but true might entrust with heavy responsibility the nature in the transmission and on operational still extremely be alternately limited， the Java user needed to do a most matter was founds applet and causes them to be photogenic mutually the communication in the Web page， this is not easy matter. JavaBeans has provided a frame package， used this package to carry on the communication to be much easier.    The JavaBeans module can through the standard attribute improvement performance which defines. Overall， JavaBeans has fully developed the Java applet function， and unified Java AWT module compact and may entrust with heavy responsibility the nature. JavaBeans module basic concept; JavaBeans is the platform independent software module which may duplicate use， the development may it directly carry on the visible operation in the software structure tool. The software structure tool may be the Web page structure， the visible application procedure structure， the CUI design structure or the server application procedure structure. Sometimes， the structure tool also may be contains child some bean the compound documents editor. JavaBeans may be the simple CUI essential factor， if the button or rolls the strip; Also may be the complex visible software module， if the database view， some JavaBeans is does not have the GUI manifestation， but these JavaBean still was allowed visibly to use the application procedure structure to carry on the combination. JavaBean and Javaapplet are similar， is extremely simple follows some kind of strict agreement the Java kind. Each JavaBean function possibly is all dissimilar below， but they all must support the characteristic. Bean has not had to inherit specific base class or connection. Visible bean must inherit the kind is java.awt.Component， like this they can increase to the visible vessel in， non- visible bean does not need to inherit this kind. Some many bean， regardless of is in the application procedure structure tool， or finally is founding in the application procedure， all has the very strong visible characteristic， but this each bean must by no means characteristic. When uses the Java programming， certainly is not all software module all needs to transform bean. Bean quite suitably has the visible operation to these and has custom-made the characteristic software module.
From basically said that， JavaBean may regard as is a black box， namely only needs to know its function but not to need to manage its internal structure the software equipment. The black box only introduced and defines its exterior characteristic and with other parts of connections， like button， window， color， shape， sentence handle and so on. Through regards as the system uses the communication network which the black box is connected， we may neglect the black box interior the system detail， thus effectively control system overall performance. As a black box model， JavaBean has 3 to meet interface， may independently carry on the development. 1 JavaBean may transfer method. 2. JavaBean provides may the read-write attribute. 3. JavaBean to exterior transmission or from exterior receive event. JavaBean module development environment; the ordinary JavaBean module is must distribute in respective environment; therefore they should be able to adapt each kind of environment. Although we are unable beforehand to know in advance JavaBean must move accurate environment， but following two are may determine: 1. bean must be able to move in an application procedure structure tool. 2. Bean must be allowed in the application procedure movement environment which produces to use. Design environment; The first explanation is bean must be allowed (design environment) center to move in the design environment. In the design environment， bean should provide the design information and allows the terminal user for the application procedure structure tool to formulate the bean outward appearance and the behavior. In the traditional software structure activity， must after the translation， the link can see the application procedure the finally movement result; But uses the JavaBean design in software， then does not have this kind of explicit boundary. Uses JavaBean， may extremely direct-viewing design application procedure software， entrusts with the software vitality in the design process. Moreover， this process is easier to duplicate develops， the design thought is easier to turn the prototype. Movement environment; The second explanation is bean must be allowed (run-time environment) center to use in the movement environment. In this environment， to designs the demand which the information and has custom-made not to be certainly unimportant. In module design environment information and the design environment compiles the code usually possibly is extremely huge.
       Therefore， we possibly need make an explicit discrimination in the bean design environment aspect and the movement environment aspect， like this possibly needs not to use bean in the movement environment any design environment code to dispose this bean. Therefore， JavaBean must separately support the movement environment connection a kind of storehouse and a design environment connection kind of storehouse.