【正文】 級應(yīng)用。第（4）類驅(qū)動程序的優(yōu)點(diǎn)在于與數(shù)據(jù)庫本身結(jié)合緊密，性能很高。適用于小型企業(yè)級應(yīng)用。應(yīng)用程序?qū)又泻?種重要的接口：。3. 提高數(shù)據(jù)庫訪問效率的幾種技術(shù) 數(shù)據(jù)庫連接池技術(shù)數(shù)據(jù)庫連接池的基本思想就是為數(shù)據(jù)庫連接建立一個“緩沖池”。預(yù)先在緩沖池中放入一定數(shù)量的鏈接，當(dāng)需要建立數(shù)據(jù)庫連接時(shí)，只需從“緩沖池”中取出一個，使用完畢之后再放回去。我們可以通過設(shè)定連接池最大連接數(shù)來防止系統(tǒng)無盡的與數(shù)據(jù)庫連接。更為重要的是我們可以通過連接池的管理機(jī)制監(jiān)視數(shù)據(jù)庫的連接的數(shù)量、使用情況，為系統(tǒng)開發(fā)、測試及性能調(diào)整提供依據(jù)。 JavaBean技術(shù)在實(shí)際應(yīng)用程序中會遇到很多程序訪問數(shù)據(jù)庫的情況，如果數(shù)據(jù)庫要修改，哪怕僅是密碼，也要改動所有的程序，所以應(yīng)當(dāng)把鏈接數(shù)據(jù)庫的操作放進(jìn)一個程序中，再需要數(shù)據(jù)庫鏈接時(shí)去調(diào)用這個文件就可以解決這個問題。一般的方法就是把數(shù)據(jù)庫鏈接做成一個JavaBean來封裝數(shù)據(jù)庫操作。JavaBean技術(shù)是一種可以重復(fù)使用且跨平臺的軟件組件，可以使用JavaBean封裝事物邏輯和客戶端操作的分離，使系統(tǒng)具有更好的靈活性和適用性。因此，使用JavaBean提高了數(shù)據(jù)庫的訪問效率。 數(shù)據(jù)庫批量更新機(jī)制數(shù)據(jù)庫批量更新的機(jī)制時(shí)通過一次調(diào)用將整批更新命令提交給數(shù)據(jù)庫，之后數(shù)據(jù)庫將一次處理所有的更新。這比將同組中的每一個更新逐一提交給數(shù)據(jù)庫的性能要高很多，大大提高了對數(shù)據(jù)庫的訪問速度。 多線程及線程池技術(shù)多線程技術(shù)主要解決處理器單元內(nèi)多個縣城執(zhí)行的問題，它可以顯著減少處理器單元的閑置時(shí)間，增加處理器單元的吞吐能力。但如果對多線程應(yīng)用不當(dāng)，會增加對單個任務(wù)的處理時(shí)間。線程池技術(shù)正是關(guān)注如何縮短或調(diào)整時(shí)間的技術(shù)，從而提高服務(wù)器程序性能的。當(dāng)使用多個較短存活期的線程有利時(shí)，可以運(yùn)用線程池急速，此技術(shù)節(jié)省了虛擬機(jī)為每項(xiàng)短期工作創(chuàng)建新進(jìn)程的工作量。另外，它使得與線程的啟動及消亡后的清理相關(guān)的開銷最小。使用此激素和可以減少反應(yīng)時(shí)間。在任務(wù)期限比較短時(shí)，線程池也是不錯的方法。附錄2 外文參考文獻(xiàn)（原文）Analysis of Java39。s Database Access Technology1. IntroductionJava language is a support network puting objectoriented programming language. Java language has absorbed Smalltalk language and C + + language of the advantages, and an increase of other features such as support for concurrent programming, network munications and control of multimedia data.2. JDBCJDBC is a SQL statement can be used for the implementation of the Java API, it is written by a number of Java class and interface ponents. JDBC architecture consists of four ponents: the application, JDBC driver manager (JDBC Driver Manager), and data sources (Data Source). JDBC API via a JDBC driver manager and for a variety of customized database JDBC driver to provide transparent connectivity of different databases. JDBC API is the role of shielding between different database JDBC drivers the difference between, making programmers from a standard, pure Java database design interface, in Java of any type of database access to provide technical support. JDBC driver manager for databasedriven application program loaded. JDBC driver associated with a specific database, and data sources used to establish connections, submit SQL requests to the database. At present, the more mon JDBC drivers are divided into about four categories: JDBCODBC bridge + ODBC driverJavaSoft products that use ODBC bridge provides JDBC access to drivers Local APIThis type of driver on the client API of the JDBC call is converted to Oracle, Sybase, Informix, DB2 and other DBMS call. JDBC Network pure Java driverThis JDBC driver will convert the DBMS has nothing to do with the network protocol, such an agreement after a server has been converted to a DBMS protocol. This Web server middleware to its pure Java client to connect to a wide range of database. The agreement depends on the specific provider. Local agreements pure Java driverThis type of JDBC driver will call directly into a DBMS network protocol used. This will allow the client and from a direct call on DBMS server, Intranet access is a very practical solution. Driver for more than four choices, to build applications that need to take into account the actual needs. In general, we remend that drivers do not apply to the bridge, that is, subsection (1) (2) class driver, which is mainly as a pure Java driver has not yet listed on the program prior to the application of the transition, the relative efficiency of the ground, the procedure can be transplanted poor. (3) (4) from the JDBC driver is the preferred method to access the database, they not only improve the portability procedures to achieve the purpose of crossplatform, but also eliminates the need to install the client driver trouble. Subsection (3) class driver is on the merits of the largest multidatabase support, so that the most flexible JDBC model, widely used with the Internet / Intranet development, a very outstanding performance. This driver supports multidatabase and distributed transaction processing and centralized management for largescale enterprise applications. Subsection (4) driver the advantage of close integration with the database itself, a high performance. Applicable to smallscale enterprise applications. Application layer containing four kinds of important interfaces: to deal with the driver loading and the establishment of a new database link. pletion of a specified database link. management database in the designated link on the implementation of the SQL statement. returned from the database result set.3. To improve the efficiency of database access in several technical database connection pool technologyDatabase connection pooling basic idea is to establish a database connection pool. Add in the buffer pool in advance a certain number of links, when the need for a database connection, simply from the pool out of one, after using the add back. We can set the connection pool through the largest number of connections to prevent system and database connection endless. More importantly, we can manage the connection pooling mechanism to monitor the number of databases, use of the system development, test and provide a basis for performance tuning. JavaBean technologyApplication in practice will encounter many situations to access the database, if the database is to be amended, even if only a password, but also all of the procedural changes, so should be to link the operation of the database into a process, then the need for a database link to call the document to be the solution to this problem. General approach is to link the database to create a JavaBean package database operations. JavaBean technology is a reuse and crossplatform software ponents, you can use the JavaBean package things the client logic and the separation operation, the system has better flexibility and applicability. Therefore, the use of JavaBean to improve the efficiency of database access. Database batch update mechanismDatabase batch update