Java-从文件中读取值？

所以我试图建立一个图表，找出两个对象之间的最短路径。要构建图形，我从输入文件读取名称和值：

Location1 0 0 0 
Location2 5 0 0 
Location3 5 5 0 
Location4 0 5 0 

我的问题是如何解读这些值？以下是我为我的主要方法所做的：

   public static void main(String[] args) {
      // You can test your program with something like this.
      In in = new In( args[0] );
      int T = in.readInt();
      for (int t=1; t<=T; t++) {
         System.out.println("Case " + t + ":") ;
         Edge w = new Edge( in );
      }
   }

我不明白的是，我如何将这些值添加到has表中，然后始终将位置与这些坐标关联。我想用Floyd-Warshall算法找到最短路径，我可以这样做：

for (int k = 0; k < n; k++) {
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            dist[i][j] = Math.min(dist[i][j], dist[i][k] + dist[k][j]);
        }
    }
}

for（int k=0；k

---

我希望这些值进入一个名为dist的2d数组，但我不知道如何将这些值分配给数组

您可以使用bufferedReader和文件读取器来完成

File file = new File(replace with file location);
FileReader fr = new FileReader(file);
BufferedReader br = new BufferedReader(fr);
while ((line = br.readLine()) != null) {
    //process line will be in the format of a String
}
br.close();

---

行将等于文件中的当前行。它将一直读取文件直到文件结束

我建议您创建一个自定义对象，例如

位置

，然后使用

哈希映射

保留链接信息

阅读完整的输入并准备

HashMap

后，您可以迭代它并进行计算

请参阅以下代码段：

位置类别：

public class Location 
{
    private String location;
    private int point1;
    private int point2;
    private int point3;

    public Location(String location, int point1, int point2, int point3) {
        this.location = location;
        this.point1 = point1;
        this.point2 = point2;
        this.point3 = point3;
    }

    public void setLocation(String location) {
        this.location= location;
    }

    public String getLocation() {
        return this.location;
    }

    public void setPoint1(int point1) {
        this.point1 = point1;
    }

    public int getPoint1() {
        return this.point1;
    }

    public void setPoint2(int point2) {
        this.point2 = point2;
    }

    public int getPoint2() {
        return this.point2;
    }

    public void setPoint3(int point3) {
        this.point3 = point3;
    }

    public int getPoint3() {
        return this.point3;
    }
}

public class Foo
{
    public static void main (String[] args)
    {
        Foo f = new Foo(); 
        f.run();
    }

    private void run() {
        Map<String,Location> locationMap = new HashMap<>();
        Scanner in = new Scanner(System.in);
        String line = null;
        while(in.hasNext()) {
            line = in.nextLine();
            String[] split = line.split(" ");
            locationMap.put(split[0],new Location(split[0],Integer.parseInt(split[1]),
                            Integer.parseInt(split[2]),Integer.parseInt(split[3])));
        }

        /* Iterate locationMap and do your calculations */
    }
}

主类：

public class Location 
{
    private String location;
    private int point1;
    private int point2;
    private int point3;

    public Location(String location, int point1, int point2, int point3) {
        this.location = location;
        this.point1 = point1;
        this.point2 = point2;
        this.point3 = point3;
    }

    public void setLocation(String location) {
        this.location= location;
    }

    public String getLocation() {
        return this.location;
    }

    public void setPoint1(int point1) {
        this.point1 = point1;
    }

    public int getPoint1() {
        return this.point1;
    }

    public void setPoint2(int point2) {
        this.point2 = point2;
    }

    public int getPoint2() {
        return this.point2;
    }

    public void setPoint3(int point3) {
        this.point3 = point3;
    }

    public int getPoint3() {
        return this.point3;
    }
}

public class Foo
{
    public static void main (String[] args)
    {
        Foo f = new Foo(); 
        f.run();
    }

    private void run() {
        Map<String,Location> locationMap = new HashMap<>();
        Scanner in = new Scanner(System.in);
        String line = null;
        while(in.hasNext()) {
            line = in.nextLine();
            String[] split = line.split(" ");
            locationMap.put(split[0],new Location(split[0],Integer.parseInt(split[1]),
                            Integer.parseInt(split[2]),Integer.parseInt(split[3])));
        }

        /* Iterate locationMap and do your calculations */
    }
}

公共类Foo
{
公共静态void main（字符串[]args）
{
Foo f=新的Foo（）；
f、 run（）；
}
私家车{
Map locationMap=newhashmap（）；
扫描仪输入=新扫描仪（系统输入）；
字符串行=null；
while（在.hasNext（）中）{
line=in.nextLine（）；
String[]split=line.split（“”）；
locationMap.put（拆分[0]，新位置（拆分[0]，Integer.parseInt（拆分[1]），
Integer.parseInt（split[2]）、Integer.parseInt（split[3]）；
}
/*迭代locationMap并进行计算*/
}
}

在这里，我使用了

System.in

从控制台读取输入。您可以替换它以从任何所需文件获取输入