java如何以指定的格式构造数据？

Question

在项目的某个地方，我需要使用Java以如下格式构造数据 语法：

{String: [(int, int),(int, int),...]};

例如：

{"some expression": [(1, 20), (2,15),...]};

我试着使用地图收藏。不知何故，我能够将外部结构格式化为 但我很难在arraylist中格式化数据

    HashMap<String, ArrayList> expressionRanges = new HashMap<String, ArrayList>();

如何使用Java获得上述示例中指定的结构

Answer 1

我想你可以用以下任何一种方法来做：

Using Map with String as Key and 2D Integer Array as Value:

// Declare the Map
Map<String, int[][]> expressionRanges = new HashMap<>();

// Declare the 2D Integer Arrays and fill them...
int[][] a = {{1, 20}, {2,15}, {3,30}};
int[][] b = {{6, 5}, {7,10}, {8,15}, {9,20},{10,25}};

// Add Integer Arrays to Map as values 
expressionRanges.put("Some Expression", a);
expressionRanges.put("Other Expression", b);

// Get 2D Integer Array from Map based on supplied Key string
int[][] tmp = expressionRanges.get("Other Expression");
// Display the contents of the 2D Integer Array
for (int i = 0;i < tmp.length; i++) {
    for (int j = 0; j < tmp[i].length; j++) {
        System.out.print(tmp[i][j] + "\t");
    }
    System.out.println();
}

如果运行，则在控制台窗口中显示以下内容：

6     5 
7     10    
8     15    
9     20    
10    25

Using Map with String as Key and 2D ArrayList as Value:

// Declare the Map
Map<String, ArrayList<ArrayList<Integer>>> expressionRanges = new HashMap<>();

// Declare the 2D ArrayLists of Integer Type and fill them...
ArrayList<ArrayList<Integer>> a1 = new ArrayList<>();
    ArrayList<Integer> b1 = new ArrayList<>(); 
        b1.add(1); 
        b1.add(20); 
        a1.add(b1); 
    ArrayList<Integer> b2 = new ArrayList<>(); 
        b2.add(2); 
        b2.add(15); 
        a1.add(b2); 
    ArrayList<Integer> b3 = new ArrayList<>(); 
        b3.add(3); 
        b3.add(30); 
        a1.add(b3); 

ArrayList<ArrayList<Integer>>a2 = new ArrayList<>();
    ArrayList<Integer> b4 = new ArrayList<>(); 
        b4.add(6); 
        b4.add(5); 
        a2.add(b4); 
    ArrayList<Integer> b5 = new ArrayList<>(); 
        b5.add(7); 
        b5.add(10); 
        a2.add(b5);  
    ArrayList<Integer> b6 = new ArrayList<>(); 
        b6.add(8); 
        b6.add(15); 
        a2.add(b6); 
    ArrayList<Integer> b7 = new ArrayList<>(); 
        b7.add(9); 
        b7.add(20); 
        a2.add(b7); 
    ArrayList<Integer> b8 = new ArrayList<>(); 
        b8.add(10); 
        b8.add(25); 
        a2.add(b8); 

// Add ArrayLists to Map as values            
expressionRanges.put("Some Expression", a1);
expressionRanges.put("Other Expression", a2);                    

// Get 2D ArrayList from Map based on supplied Key string
ArrayList<ArrayList<Integer>> values =  expressionRanges.get("Other Expression");
// Display the contents of the 2D ArrayList
for(int i = 0; i < values.size(); i++){
    for(int j = 0; j < values.get(i).size(); j++){
        System.out.print(values.get(i).get(j) + "\t");
    }
    System.out.println();
}

如果运行，则在控制台窗口中显示以下内容：

6     5 
7     10    
8     15    
9     20    
10    25