学习笔记3没有体现面向对象。学习笔记4的功能和3是一样的，只不过用面向对象的方法来实现，就是先申明一个SimpleBug类，类有数据成员，成员函数，构造函数。
然后在StartSimpleBug中调用SimpleBug类。
需要掌握
1 import swarm.Globals;//任何类申明时都要用到。
2 import swarm.defobj.Zone;//Zone的定义
3 import swarm.objectbase.SwarmObjectImpl;//SwarmObjectImpl的定义
4 构造函数有六个参数
public SimpleBug(Zone aZone, int wXSize, int wYSize, int X, int Y,
int bNum)
Zone 参数表示世界的初始化。
SimpleBug类:
/SimpleJavaBug/SimpleBug.java
// SimpleBug.java
// Defines the class for our SimpleBug agents.
import swarm.Globals;
import swarm.defobj.Zone;
import swarm.objectbase.SwarmObjectImpl;
public class SimpleBug extends SwarmObjectImpl
{
// These instance variables keep track of the size of a given
// bug's world, its position within it, and its identity.
int worldXSize;
int worldYSize;
int xPos;
int yPos;
int bugNumber;
// Constructor to create a SimpleBug object in Zone aZone and to
// place it at the specified X,Y location in its world. The bug
// is also given a numeric id, bNum.
public SimpleBug(Zone aZone, int wXSize, int wYSize, int X, int Y,
int bNum)//构造函数
{
// Call the contructor for the bug's parent class.
super(aZone);//暂时没搞明白
// Record the bug's world size, its initial position and id
// number.
worldXSize = wXSize;
worldYSize = wYSize;
xPos = X;
yPos = Y;
bugNumber = bNum;
// Announce the bug's presence to the console.
System.out.println("SimpleBug number " + bugNumber +
" has been created at " + xPos + ", " + yPos);
}
// This is the method to have the bug take a random walk backward
// (-1), forward (+1), or not at all (0) in first the X and then
// the Y direction. The randomWalk method uses
// getIntegerWithMin$withMax() to return an integer between a
// minimum and maximum value, here between -1 and +1.
// Globals.env.uniformRand is an instance of the class
// UniformIntegerDistImpl, instantiated by the call to
// Globals.env.initSwarm in StartSimpleBug. Note that the bug's
// world is a torus. If the bug walks off the edge of its
// rectangular world, it is magically transported (via the modulus
// operator) to the opposite edge.
public void randomWalk()
{
xPos += Globals.env.uniformIntRand.getIntegerWithMin$withMax(
-1, 1);
yPos += Globals.env.uniformIntRand.getIntegerWithMin$withMax(
-1, 1);
xPos = (xPos + worldXSize) % worldXSize;
yPos = (yPos + worldYSize) % worldYSize;
}
// Method to report the bug's location to the console.
public void reportPosition()
{
System.out.println("Bug " + bugNumber + " is at " + xPos +
", " + yPos);
}
}
StartSimpleBug类：
在这里需要掌握：
1 Globals.env.initSwarm()，这是Swarm的Global环境的一个静态方法。这个方法建立了Swarm的全局变量和方法，每一个Swarm程序都以它开始。它有四个参数：仿真的类的名字、Swarm的版本、报告Swarm漏洞的email地址以及运行程序的命令字符串。
/SimpleJavaBug/StartSimpleBug.java
// StartSimpleBug.java
// The Java SimpleBug application.
import swarm.Globals;
import swarm.defobj.Zone;
public class StartSimpleBug
{ // The size of the bug's world and its initial position.
static int worldXSize = 80;
static int worldYSize = 80;
static int xPos = 40;
static int yPos = 40;
public static void main (String[] args)
{
int i;
SimpleBug abug;
// Swarm initialization: all Swarm apps must call this first.
Globals.env.initSwarm ("SimpleBug", "2.1",
"[email protected]", args); //在这个过程中声明了SimpleBug用到的随机生成函数
// Create an instance of a SimpleBug, abug, and place it
// within its world at (xPos, yPos). The bug is created in
// Swarm's globalZone and is given a "bug id" of 1.
abug = new SimpleBug(Globals.env.globalZone, worldXSize, worldYSize,
xPos, yPos, 1);
// Loop our bug through a series of random walks asking it to
// report its position after each one.
for (i = 0; i < 100; i++)
{
abug.randomWalk();
abug.reportPosition();
}
}
}