1,Java抛弃了头文件、预处理机制、goto语句和多维数组。 2,Java不支持指针。 3,Java抛弃了联合体和结构体。 4,Java不支持独立函数。所有函数必须在类中声明。 5,Java不支持多重继承,可以使用接口模拟多重继承。 6,Java不支持运算符重载。 7,Java中布尔型不再用整数来代替。 8,Java中主函数必须有一个字符串类型的参数。 Java抛弃的C++中的这些机制和结构多数都是“危险”的,减少了语言的复杂性,增强了安全性,虽然在一定程度上减少了其灵活性。

Java Calling Native Functions in .DLL on Windows

How to call a function in .dll from Java on Windows is introduced in this post with an example. Platforms used: OS: Microsoft Windows XP [5.1.2600] C to .dll compiler: MS Visual Studio 2008 JDK: java -version java version “1.6.0_05” Java(TM) SE Runtime Environment (build 1.6.0_05-b13) Java HotSpot(TM) Client VM (build 10.0-b19, mixed mode, sharing) […]

JSP Connecting to MySQL

We use tomcat as the container used for instructions in the post. 1) Download the driver mysql-connector-java-*.*.*-bin.jar and put it into WEB-INF/lib/, and remember to restart tomcat. 2) The example code as follows. String driverName="com.mysql.jdbc.Driver"; String userName="username"; String userPasswd="password"; String dbName="dbname"; String tableName="tablename"; String url="jdbc:mysql://localhost/"+dbName+"?user="+userName+"&password="+userPasswd; Class.forName("com.mysql.jdbc.Driver").newInstance(); Connection conn=DriverManager.getConnection(url); Statement statement = conn.createStatement(); String sql="SELECT * […]

Hadoop TeraSort Benchmark

TeraSort is one of Hadoop’s widely used benchmarks. Hadoop’s distribution contains both the input generator and sorting implementations: the TeraGen generates the input and TeraSort conducts the sorting. Here, we provide a short tutorial for using the Hadoop TeraSort benchmark. TeraGen generates random data that can be used as input data for a subsequent running […]