北京地铁项目
github：https://github.com/leo-xlz/Subway-beijing
模块分析-----
zucc.edu.cn.model
存放站点信息和路径信息
station.java
private String name;//站点名字
private String line;//所属路线
private List<Station> linkStations = new ArrayList<>();//相邻连接站点
routine.java
private Station star;//起点
private Station end;//终点
private int distance;
private List<Station> path=new ArrayList<>();
main 调用函数并且运行
main.java
public static void main(String[] args) throws UnsupportedEncodingException {
switch (args[0]) {
//读入subway.txt文件数据
case "-map":
//-map subway.txt
if (args.length == 2) {
FileOperate.Readfile = System.getProperty("user.dir") + File.separator + args[1];
//根据路径，读取地铁信息，并打印。
FileOperate.getFile();
System.out.println("成功读取subway.txt文件");
} else {
System.out.println("验证参数格式！");
}
break;
//查询指定线路的文件数据，并写入到station.txt文件中
case "-a":
//-a 1号线 -map subway.txt -o station.txt
if (args.length == 6) {
FileOperate.Readfile = System.getProperty("user.dir") + File.separator + args[3];
FileOperate.Writefile = System.getProperty("user.dir") + File.separator + args[5];
FileOperate.getFile();
System.out.println(args[1]);
if (FileOperate.Map.keySet().contains(args[1])) {
FileOperate.loadLine(args[1]);
System.out.println("已将地铁" + args[1] + "的各站点信息写入station.txt文件");
} else {
System.out.println("线路不存在");
}
} else {
System.out.println("验证参数格式！");
}
break;
//查询指定站点之间的最短路径信息
case "-b":
//-b 天安门西 北京大学东门 -map subway.txt -o routine.txt
System.out.println(1);
if (args.length == 7) {
FileOperate.Readfile = System.getProperty("user.dir") + File.separator + args[4];
FileOperate.Writefile = System.getProperty("user.dir") + File.separator + args[6];
FileOperate.getFile();
FileOperate.shorestPath(args[1],args[2]);
System.out.println("已将" + args[1] + "到" + args[2] + "最短路径的结果写入routine. txt文件");
} else {
System.out.println("验证参数格式！");
}
break;
default:
System.out.println("验证参数格式！");
}
}
zucc.edu.cn.manager
Dijkstra.java 最短路径算法
public static HashMap<Station, Routine> resultMap = new HashMap<>();//结果集
public static List<Station> list = new ArrayList<>();//分析过的站点
public static Routine dijkstra(Station star, Station end) {
if (!list.contains(star))
list.add(star);
if (star.equals(end)) {//如果起始点和终点相同，直接返回
Routine result = new Routine();
result.setDistance(0);
result.setEnd(star);
result.setStar(star);
resultMap.put(star, result);
return resultMap.get(star);··
}
if (resultMap.isEmpty()) {
List<Station> linkedStation = getLinkStations(star);
for (Station station : linkedStation) {
Routine routine = new Routine();
routine.setStar(star);
routine.setEnd(station);
routine.setDistance(1);
routine.getPath().add(station);
resultMap.put(station, routine);
}
}
Station next = getNextStation();
if (next == null) {
Routine routine = new Routine();
routine.setDistance(0);
routine.setStar(star);
routine.setEnd(end);
return resultMap.put(end, routine);
}
//如果得到的最佳邻接点与终点相同，则直接返回结果集
if (next.equals(end))
return resultMap.get(next);
List<Station> bestlinkStation = getLinkStations(next);
for (Station best : bestlinkStation) {
if (list.contains(best))
continue;
int distance =0;
if (next.getName().equals(best.getName()))
distance = 0;
distance = resultMap.get(next).getDistance() + 1;
List<Station> nextPass = resultMap.get(next).getPath();
Routine res = resultMap.get(best);
if (res != null) {
if (res.getDistance() > distance) {
res.setDistance(distance);
res.getPath().clear();
res.getPath().addAll(nextPass);
res.getPath().add(best);
}
} else {
res = new Routine();
res.setDistance(distance);
res.setStar(star);
res.setEnd(best);
res.getPath().addAll(nextPass);
res.getPath().add(best);
}
resultMap.put(best, res);
}
list.add(next);
return dijkstra(star, end);
}
//通过计算最小权值 计算下一个需要分析的点
private static Station getNextStation() {
int min = 1000;
Station rets = null;
Set<Station> stations = resultMap.keySet();
for (Station station : stations) {
if (list.contains(station)) {
continue;
}
Routine result = resultMap.get(station);
if (result.getDistance() < min) {
min = result.getDistance();
rets = result.getEnd();
}
}
return rets;
}
- FileOperate.java 文件处
读取文件，通过 HashMap<String,List> Map来存放地铁线路信息
public static String Readfile;
public static String Writefile;
public static HashMap<String,List<Station>> Map=new HashMap<>();//存放地铁线路信息
public static HashSet<List<Station>> lineSet=new LinkedHashSet<>();//所有线路的集合
public static void getFile() {
File file=new File(Readfile);
BufferedReader rd=null;
/* 读取数据 */
try {
InputStreamReader inputStreamReader = new InputStreamReader(new FileInputStream(file),"UTF-8");
rd=new BufferedReader(inputStreamReader);
String lineTxt = null;
while ((lineTxt = rd.readLine()) != null) {
String[] s = lineTxt.split(" ");//创建一个临时存放数据的数组
List<Station> Stations = new ArrayList<>();
for(int i = 1;i<s.length;i++){ //将读入的站点并加入到对应线路的List中
Station station = new Station(s[i],s[0]);
Stations.add(station);
}
lineSet.add(Stations);
Map.put(s[0],Stations);
}
rd.close();
} catch (UnsupportedEncodingException e) { //异常处理
e.printStackTrace();
} catch (FileNotFoundException e) {
e.printStackTrace();
}catch (IOException e) {
e.printStackTrace();
} finally {
}
}
public static void loadLine(String Line){ //根据指定的路线输出此路线的所有站点
File file=new File(Writefile);
List<Station> line;
BufferedWriter bw = null;
try {
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(new FileOutputStream(file),"UTF-8");
bw = new BufferedWriter(outputStreamWriter);
line=Map.get(Line);
bw.write(Line+"\n");
bw.write("--------\n");
bw.write("--------\n");
for(int i=0;i<line.size();i++)
bw.write(line.get(i).getName()+"\r\n");//写入指定路线的站点信息
bw.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public static String getLineName(Station station){//根据站点名称得到线路名称
String sName=station.getName();
for(Map.Entry<String,List<Station>>entry:Map.entrySet()){
List<Station> stations=entry.getValue();
for(Station s:stations){
if(s.getName().equals(sName))
return entry.getKey();
}
}
return null;
}
public static void shorestPath(String star,String end){
File file = new File(Writefile);
BufferedWriter bw = null;
try{
OutputStreamWriter outputStreamWriter = new OutputStreamWriter(new FileOutputStream(file),"UTF-8");
bw = new BufferedWriter(outputStreamWriter);
Routine routine=Dijkstra.dijkstra(new Station(star),new Station(end));
bw.write((routine.getPath().size()+1)+"\r\n");
String lineName=getLineName(routine.getStar());
bw.write(lineName+"\n");
bw.write(routine.getStar().getName()+"\n");
for(int i=0;i<routine.getPath().size()-1;i++) {
bw.write(routine.getPath().get(i).getName()+"\n");
if(!routine.getPath().get(i+1).getLine().equals(routine.getPath().get(i).getLine())){
bw.write("---需换乘"+routine.getPath().get(i+1).getLine()+"---\n");
}
}
bw.write(routine.getEnd().getName()+"\n");
bw.close();
}catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
遇到的问题
1.环线不知道怎么设计
2.HashMap<String,List
3.编写迪杰斯特拉算法不够熟练
4.准备工作没有做好，没有先画一张草图来预先模拟一下各个功能怎么实现，同时没有将各个存储结构的关系画出来，以至于在写代码时经常会弄混各个结构。
所做工作
1.文件的读入与输出
2.数据存储结构的编辑
3.编写迪杰斯特拉算法来输出最短路径
测试
1.程序启动时需要通过读取 -map 参数来获得对应的自定义地铁文件（命名为 subway.txt），从而得到地铁线路图的信息。
java subway -map subway.txt
2.给定路线，输出此路线上所有站点，保存信息到station.txt
java subway -a 1号线 -map subway.txt -o station.txt
3.给出两个站点，输出两点间的最短路径,保存文件到routine.txt
subway.exe -b 香山 焦化厂 -map subway.txt -o routine.txt
