1.在web上面运行是这样的.
2.在Eclipse里面运行是这样的.
3.下面是代码
4.问题：是不是要自己创建显示图形extend JFrame什么的?程序报空指针异常,未初始化实在弄不明白。如何在Eclipse里面显示出来？
package example;
class Node {
double x,y,dx,dy;
boolean fixed;
String lbl;
}
class Edge {
int from,to;
double len;
}
class GraphPanel extends Panel
implements Runnable, MouseListener, MouseMotionListener {
Graph graph;
int nnodes;
Node nodes[] = new Node[100];
int nedges;
Edge edges[] = new Edge[200];
Thread relaxer,stress;
boolean random;
int numMouseButtonsDown = 0;
GraphPanel(Graph graph) {
this.graph = graph;
addMouseListener(this);
}
int findNode(String lbl) {
for (int i = 0 ; i < nnodes ; i++) {
if (nodes[i].lbl.equals(lbl)) {return i;}
}
return addNode(lbl);
}
int addNode(String lbl) {
Node n = new Node();
n.x = 10 + 380*Math.random();
n.y = 10 + 380*Math.random();
n.lbl = lbl;
nodes[nnodes] = n;
return nnodes++;
}
void addEdge(String from, String to, int len) {
Edge e = new Edge();
e.from = findNode(from);
e.to = findNode(to);
e.len = len;
edges[nedges++] = e;
}
public void run() {
Thread me = Thread.currentThread();
while (relaxer == me) {
relax();
if (random && (Math.random() < 0.03)) {
Node n = nodes[(int)(Math.random() * nnodes)];
if (!n.fixed) {
n.x += 100*Math.random() - 50;
n.y += 100*Math.random() - 50;
}
graph.play(graph.getCodeBase(), "audio/drip.au");
}
try {
Thread.sleep(100);
} catch (InterruptedException e) {
break;
}
}
}
synchronized void relax() {
for (int i = 0 ; i < nedges ; i++) {
Edge e = edges[i];
double vx = nodes[e.to].x - nodes[e.from].x;
double vy = nodes[e.to].y - nodes[e.from].y;
double len = Math.sqrt(vx * vx + vy * vy);