JAva遍歴MapおよびMapから二次元配列への変換例

JAva遍歴MapおよびMapから二次元配列への変換例
インスタンスコード:

import java.util.HashMap; 
import java.util.Iterator; 
import java.util.Map; 
 
public class Test { 
  public static void main(String[] args) { 
    int a = 0, b = 0, c = 0; 
    //    :  Map.keySet()  Map  Map        
    Map map1 = new HashMap(); 
    map1.put("012013012013", "  "); 
    map1.put("012013012014", "  "); 
    String[][] group1 = new String[map1.size()][2]; 
    System.out.println("   :  Map.keySet()  map1 key value"); 
    for (String key : map1.keySet()) {  
      System.out.println("key = " + key + " and value = " + map1.get(key));  
      group1[a][0] = key; 
      group1[a][1] = map1.get(key); 
      a++; 
    }  
    System.out.println("map1.size() ：" + map1.size() + ",a ：" + a + "，group1      ：" + group1.length); 
    System.out.println("----------------------------------------------------"); 
    for(int n = 0; n < group1.length; n++) { 
      System.out.println("key = " + group1[n][0] + " and value = " + group1[n][1]);  
    } 
     
    //    :  Map.entrySet()  iterator()  Map  Map        
    Map map2 = new HashMap(); 
    map2.put("112013012013", "  "); 
    map2.put("112013012014", "  "); 
    System.out.println("
" + "   :  Map.entrySet()  iterator()  map2 key value"); 
    Iterator> iterator = map2.entrySet().iterator();  
    String[][] group2 = new String[map2.size()][2]; 
    while (iterator.hasNext()) {  
      Map.Entry entry = iterator.next();         
      System.out.println("key = " + entry.getKey() + " and value = " + entry.getValue()); 
      group2[b][0] = entry.getKey(); 
      group2[b][1] = entry.getValue(); 
      b++; 
    }  
    System.out.println("map2.size() ：" + map2.size() + ",b ：" + b + "，group2      ：" + group2.length); 
    System.out.println("----------------------------------------------------"); 
    for(int n = 0; n < group2.length; n++) { 
      System.out.println("key = " + group2[n][0] + " and value = " + group2[n][1]);  
    } 
     
    //    :  Map.entrySet()    Map  Map        
    Map map = new HashMap(); 
    map.putAll(map1); 
    map.putAll(map2);   
    String[][] group3 = new String[map.size()][2]; 
    System.out.println("
" + "   :  Map.entrySet()  map key value ");    
    for (Map.Entry entry : map.entrySet()) {  
      System.out.println("key = " + entry.getKey() + " and value = " + entry.getValue());  
      group3[c][0] = entry.getKey(); 
      group3[c][1] = entry.getValue(); 
      c++; 
    } 
    System.out.println("map.size() ：" + map.size() + ",c ：" + c + "，group3      ：" + group3.length); 
    System.out.println("----------------------------------------------------"); 
    for(int n = 0; n < group3.length; n++) { 
      System.out.println("key = " + group3[n][0] + " and value = " + group3[n][1]);  
    } 
     
  } 
} 

出力結果:

   :  Map.keySet()  map1 key value 
key = 012013012013 and value =    
key = 012013012014 and value =    
map1.size() ：2,a ：2，group1      ：2 
---------------------------------------------------- 
key = 012013012013 and value =    
key = 012013012014 and value =    
 
   :  Map.entrySet()  iterator()  map2 key value 
key = 112013012014 and value =    
key = 112013012013 and value =    
map2.size() ：2,b ：2，group2      ：2 
---------------------------------------------------- 
key = 112013012014 and value =    
key = 112013012013 and value =    
 
   :  Map.entrySet()  map key value  
key = 112013012014 and value =    
key = 112013012013 and value =    
key = 012013012013 and value =    
key = 012013012014 and value =    
map.size() ：4,c ：4，group3      ：4 
---------------------------------------------------- 
key = 112013012014 and value =    
key = 112013012013 and value =    
key = 012013012013 and value =    
key = 012013012014 and value =    

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