Map中的value为对象

曾经终败给现在 2022-05-28 07:08 159阅读 0赞

有一个Map集合，里面存放的是<String,int>类型的数据。

想把上述中的特点1、特点2、特点3变成城市的属性，变成Map<String,CityObj>类型，CityObj为对象，有属性特点1、特点2、特点3。

转换成：

代码实现：

import java.util.HashMap;
    import java.util.Map;
    
    /** 
     * @author  
     * @date 2018年4月10日 上午11:30:24 
     * @version 1.0 
     * @parameter  
     * @since  
     * @return  
     */
    public class TestMap {
    	public static class CityObj{
    		public String city;
    		public int level1;
    		public int level2;
    		public int level3;
    		public void setValue(String level,int value) {
    			if (level.equals("特点1")) {
    				this.level1=value;
    			}else if (level.equals("特点2")) {
    				this.level2=value;
    			}else if (level.equals("特点3")) {
    				this.level3=value;
    			}
    		}
    
    //		@Override
    //		public String toString() {
    //			return "CityObject [values=" + Arrays.toString(values) + "]";
    //		}
    	}
    	
    	public static void main(String[] args) {  
    		Map<String, Integer> rMap = new HashMap<>();
    		Map<String, CityObj> resMap = new HashMap<>();
                    rMap.put("北京市_特点1",  52);  
                    rMap.put("北京市_特点2",  86);  
                    rMap.put("上海市_特点1",  32);  
                    rMap.put("长沙市_特点3",  78);  
                    rMap.put("武汉市_特点2",  50);  
                    rMap.put("南京市_特点1",  26);  
                    rMap.put("上海市_特点2",  90);  
                    for (Map.Entry<String, Integer> entry : rMap.entrySet()) {  
                        System.out.println(entry.getKey() + '\t' + entry.getValue());  
                    }  
                      System.out.println();
                    for (Map.Entry<String, Integer> entry : rMap.entrySet()) {  
                        String key = entry.getKey();  
                        int count = entry.getValue();  
      
                        int p = key.indexOf("_");  
                        if (p >= 0) {  
                            String newKey = key.substring(0, p);  
                            String level = key.substring(p + 1);  
                            System.out.println("level:" + '\t' + level);  
                            if (resMap.containsKey(newKey)) {  
                                CityObj cityObj = resMap.get(newKey);  
                                cityObj.setValue(level, count);  
                            } else {  
                                CityObj cityObj = new CityObj();  
                                cityObj.setValue(level, count);  
                                resMap.put(newKey, cityObj);  
                            }  
                        }  
                    }  
                        for (Map.Entry<String, CityObj> entry : resMap.entrySet()) {  
                            System.out.println(entry.getKey() + '\t' + entry.getValue().level1+ '\t' + entry.getValue().level2+ '\t' + entry.getValue().level3);  
                }  
        }
    }

输出结果：

北京市_特点1	52
    上海市_特点2	90
    南京市_特点1	26
    武汉市_特点2	50
    北京市_特点2	86
    上海市_特点1	32
    长沙市_特点3	78
    
    长沙市	0	0	78
    上海市	32	90	0
    北京市	52	86	0
    南京市	26	0	0
    武汉市	0	50	0

或者：

import java.util.Arrays;
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Map.Entry;
    
    class CityObject{
    	private int [] values = new int[4];
    
    	public int[] getValues() {
    		return values;
    	}
    
    	public void setValueAt(int index, int value) {
    		if (index < 0 || index > 3) {
    			return;
    		}
    		this.values[index] = value;
    	}
    
    	@Override
    	public String toString() {
    		return "CityObject [values=" + Arrays.toString(values) + "]";
    	}
    	
    	
    	
    }
    
    public class Main{
    	
    	public static HashMap<String, Integer> cityMaps = new HashMap<>();
    	public static HashMap<String, CityObject> cityMaps2 = new HashMap<>();
    	
    	static {
    		cityMaps.put("上海市_0", 30);
    		cityMaps.put("上海市_1", 40);
    		cityMaps.put("北京市_2", 50);
    		cityMaps.put("长沙市_2", 80);
    		cityMaps.put("海南市_3", 90);
    		cityMaps.put("昆明市_1", 20);
    		cityMaps.put("武汉市_2", 10);
    	}
    	
    	public static void convert() {
    		Iterator<Entry<String, Integer>> iter = cityMaps.entrySet().iterator();
    		while (iter.hasNext()) 
    		{
    			Map.Entry entry = (Map.Entry) iter.next();
    			String key = (String)entry.getKey();
    			int val = (int) entry.getValue();
    			
    			
    			String[] subKeys = key.split("_");
    			
    			String newKey = subKeys[0];
    			int cityObjIndex = Integer.valueOf(subKeys[1]);
    			
    			if (cityMaps2.containsKey(newKey)) {
    				CityObject object = cityMaps2.get(newKey);
    				object.setValueAt(cityObjIndex, val);
    			}else {
    				CityObject object = new CityObject();
    				object.setValueAt(cityObjIndex, val);
    				cityMaps2.put(newKey, object);
    			}
    			
    		}
    	}
    	
    	public static void output() 
    	{
    		Iterator<Entry<String, CityObject>> iter = cityMaps2.entrySet().iterator();
    		while (iter.hasNext()) 
    		{
    			Map.Entry entry = (Map.Entry) iter.next();
    			String key = (String)entry.getKey();
    			CityObject val = (CityObject)entry.getValue();
    			
    			System.out.println("key = "+key + ",value = " + val.toString());
    		}
    	}
    	public static void main(String[] args) {
    		convert();
    		output();
    	}
    }

输出结果：

key = 昆明市,value = CityObject [values=[0, 20, 0, 0]]
    key = 长沙市,value = CityObject [values=[0, 0, 80, 0]]
    key = 海南市,value = CityObject [values=[0, 0, 0, 90]]
    key = 上海市,value = CityObject [values=[30, 40, 0, 0]]
    key = 北京市,value = CityObject [values=[0, 0, 50, 0]]
    key = 武汉市,value = CityObject [values=[0, 0, 10, 0]]