It seems that php is popular in developing websites now, so where is javaweb generally used? What are the differences, advantages and disadvantages between them?

At present, oa in the market can basically be divided into two camps, namely php camp and java camp. For users who have been exposed to oa for a short time, they often only see the appearance and obvious price difference, and it is difficult to see the actual difference between them. In fact, the value of PHP+MYSQL is not limited to oa software, but the software developed by PHP+MYSQL is not as valuable as the software developed by java. Why is OA of php+MYSQL worthless? We must first understand the difference between PHP and java.

1, system technical architecture comparison

Layering is an effective way to organize systems, and the idea of divide and conquer is a very important idea in the computer field. Under the guidance of good hierarchical thinking, we can achieve "high cohesion and low coupling", separate specific problems, and facilitate the control, expansion and allocation of resources. PHP can only realize a simple distributed two-tier or three-tier architecture, while JAVA is very powerful in this respect and can realize a multi-tier network architecture. Using MVC design pattern can make oa system have a more efficient and reasonable system architecture. The backward technical architecture makes the oa software system written by php inherently insufficient, and it can't make up for its inherent disadvantages the day after tomorrow. The gap between this system and oa software system written in JAVA is getting bigger and bigger in expansibility and demand adaptability. The gap in architecture determines that oa made by php is a small jasper at best, and it will never be as good as a good family like java.

2, database access comparison

PHP can be compiled with functions connected to many databases. I will write my own peripheral functions to access the database indirectly. In this way, when the used database changes, the coding can be easily modified to adapt to such changes. However, the database interface support provided by PHP is different, such as the interfaces to Oracle, MySQL and Sybase. Because PHP uses different database access interfaces for different databases, the universality of database access codes is not strong.

Java accesses the database through JDBC, and it is more convenient to access the database through database drivers provided by different database vendors, and the interface for accessing the database is relatively unified. If the web application developed is also converted from MYSQL data to ORACLE data, PHP needs to do a lot of modification work, and it is cumbersome. But things developed by JAVA can be realized with only a few changes.

The difference of database access methods determines that oa developed by php and oa developed by java are the gap between carriages and trains. The former can only follow the trend and the quota is limited, while the latter is the crystallization of industrialization, which can accommodate everything and steadily increase the speed.

3. Safety comparison

In the face of open source and cross-platform java, php has lost many advantages. Especially in terms of code security. The development program of php can be easily modified after others get the code. However, the programs developed by java have high security because they can't see the complete source code and can only see some compiled class files. Coupled with the advantages of system architecture, php and java are far from each other in security.

If we have to compare the security of php and java, the same thief patronizes php, that is, he can take whatever he wants, change it at will, and visit Ikki with great pleasure. When you visit Java, you will find police guarding it, and there is an automatic alarm device inside, even if you break through many obstacles and enter the room. All the valuables are put in the encrypted safe, so you can only look at the ocean and sigh, and return home with clothes.

4. Forward-looking and developmental

Generally speaking, php is suitable for small and medium-sized systems, and java is suitable for large systems. Php can do a single event well, but it is not suitable for completing multiple highly integrated concurrent events. Why php is suitable for small and medium-sized systems but not for large systems?

First of all, php lacks multi-tier structure support. For large system load sites, only distributed computing can be used. Database, application logic layer and presentation logic layer are separated from each other, and the flow of the same layer is separated to form a two-dimensional array. And php just lacks this support.

Secondly, the database interface provided by PHP is not uniform, and it takes great efforts to unify multiple different database data. JAVA, on the other hand, has no such defects. Scale support can be obtained through JavaClass and EJB of SUNJava, and structural support can be obtained through EJB/CORBA and ApplicationServer of many manufacturers. For example, IBM's e-commerce, whose core is WebSphere using JSP/Servlet, supports CGI.

If you compare Php to a general, you have the ability to be independent. Then java is a handsome talent, with good foresight and expansibility, and strong overall layout and synergy. Can command thousands of troops and horses, and finally compete for the Central Plains.

5. Development cost comparison

Since php is inferior to java in many aspects, why do oa products developed by php compete with java products is that the Php camp generally takes the low-end route, while the java camp takes the high-end route. The intersection area of the two is very small.

The price of software is largely linked to its own cost and function. The entry threshold of php is low, and most programmers who have studied C can easily transform into php programmers, which makes php programmers flood and low-cost php software products emerge one after another. Take PHP+MySQL+Apache, the most classic combination of PHP, as an example. Because all software is open source and free, the investment is not high.

Java development needs a specific environment, and it takes some time to become a qualified java programmer, and the cost of Java programmers is several times that of php. Java's web application servers are all free, such as Tomcat and JBoss. WebSphere and Weblogic must choose good business services. The cost of this investment is actually n times that of php. Therefore, the cost of developing oa with java is much higher than that of similar software products developed with php. However, due to the high cost of java development, it is difficult to realize the possibility of plagiarism and short-term transcendence, which also makes the threshold of products developed with java higher.

Not afraid of not knowing the goods, but afraid of shopping around. Products developed by Php can also be used, but they are not as good as similar products developed by java. It is precisely because the overall performance of the products developed by php is far from that of java, so php uses the advantages of low cost and low price to fight against similar java products and balance the mentality of buyers with the price gap. So it is not surprising that the OA of PHP+MYSQL is worthless.

The second type

Comparing the two Web development technologies, PHP and JSP, is actually comparing the web development of PHP and Java in the current situation. The following is my comparison in several major aspects:

First, language contrast.

Php is a server scripting language that interprets execution. First of all, php is easy to use. Grammar is similar to C language, so programmers who have studied C language can quickly become familiar with the development of php. Java needs to learn the grammar of Java, be familiar with some core class libraries and know the object-oriented programming method. So java is not as easy to learn as php.

Java must first be compiled into bytecode. Class files, and then interpreted and executed on the Java virtual machine. The first thing that comes to mind in java web development is JSP (now JSP2.0). The initial java web development was realized by servlet, which required programmers to embed a large number of html codes in java source files. So jsp appeared later, which can be easily embedded into html files. In fact, when JSP files are executed on the server, they are first converted into servlet by the application server, and then compiled and executed. Jsp can produce powerful functions through the support of servlet and JavaBean. JavaBean is a reusable and cross-platform software component. Using javabean can easily separate java code from html, and enhance the system function and software reusability.

Web development of Java belongs to J2EE specification defined by SUN Company. Moreover, J2EE includes all aspects of java web development, such as JSP, Servlet, JDBC, JNDI, JAVABEAN, EJB and so on. J2EE is especially suitable for large enterprises.

Second, database access comparison

Java accesses the database through JDBC, and it is convenient to access the database through database drivers provided by different database vendors. The interface for accessing the database is relatively uniform.

PHP uses different database access interfaces for different databases, so the database access code is not universal. For example, a web application developed in Java needs only a few modifications when it is transferred from MySQL database to Oracle database. On the other hand, PHP needs a lot of modification.

Third, the system design architecture comparison

Web development technology using Java needs object-oriented system design method, while PHP still adopts process-oriented development method. Therefore, a lot of system analysis and design work need to be done in the early stage of Java development.

Fourth, cross-platform.

Both Java and PHP have good cross-platform features. Almost all of them can run on different operating systems such as Linux or Windows without any modification.

Comparison of Development Costs of verbs (Verb Abbreviations)

The most classic combination of PHP is PHP+MySQL+Apache. It is very suitable for developing small and medium-sized web applications, and the development speed is relatively fast. And all the software is open source and free, which can reduce investment.

Java's web application servers include free Tomcat and JBoss. If you need better business services, there are WebSphere and Weblogic.

Comparison of distributed multi-layer architecture of intransitive verbs

PHP can only realize a simple distributed two-tier or three-tier architecture, while JAVA is more powerful in this respect and can realize a multi-tier network architecture. Database layer (persistence layer), application (business) logic layer and presentation logic layer are separated from each other, and now different layers have been supported by some mature development frameworks. For example, Struts uses java's web development technology to realize MVC design pattern, the business logic layer also has Spring framework, and the database persistence layer also has Hibernate framework. These frameworks can facilitate developers to build multi-tier business applications efficiently, reasonably and scientifically.

Let me briefly talk about Struts, which is essentially an MVC (Model, View, Controller) framework based on JSPModel2. JSPModel2 architecture is a method to provide dynamic content by combining JSP and Servlet. In Struts framework, the model is composed of JavaBean or EJB components that realize business logic, the controller is realized by Servlet, and the view is composed of a set of JSP files. Struts can be used to define the roles and division of labor between developers and web designers. And the more complex the project, the more obvious the advantages.

Seven. Source code security

The source code of the program developed by php is public, and others can modify it after they get the program developed by PHP.

Java development program, the end user only gets some compiled classes, but can't see the complete source code, which is highly secure.

Eight. performance comparison

Some people have done experiments to test the loop performance and access to Oracle database of these two languages respectively.

In the loop performance test, JSP ended the loop of 20000 * 20000 in an amazing 4 seconds. PHP tested 2000 * 2000 cycles (one order of magnitude less), but it took 63 seconds respectively.

In the database test, they insert, update, select and delete respectively: JSP Oracle8 performs 1000 times; JSP needs 13 seconds, and PHP needs 69 seconds.

Comparison between table 1 PHP and Java

PHPJAVA

Low reusability and high reusability

speed of development

Poor maintainability

Excellent portability-Linux, Windows, Unix, etc.

Low security, high security.

Low development cost and high cost.

Multi-tier architecture is not optimized well.

The database access interface is not uniform.

Poor expansibility

Object-oriented differential optimization

To sum up, PHP is suitable for the rapid development of small and medium-sized application systems, with low development cost and quick response to changing requirements. Java is suitable for developing large-scale application systems, with broad application prospects, easy maintenance and good reusability. Also, the price of a system with the same function developed in Java is higher than that developed in PHP.