将List中的一个值取出来作为键

Question

[
{
"offline": 2,
"station": "北流村",
"online": 23
},
{
"offline": 31,
"station": "马池口",
"online": 210
},
{
"offline": 92,
"station": "北七家",
"online": 0
},
{
"offline": 50,
"station": "龙园",
"online": 88
},
{
"offline": 16,
"station": "南口",
"online": 162
},
{
"offline": 44,
"station": "兴寿",
"online": 40
},
{
"offline": 90,
"station": "百善",
"online": 39
},
{
"offline": 172,
"station": "平西府",
"online": 48
},
{
"offline": 41,
"station": "霍营",
"online": 40
},
{
"offline": 72,
"station": "南邵",
"online": 72
},
{
"offline": 17,
"station": "居庸关",
"online": 0
},
{
"offline": 51,
"station": "崔村",
"online": 62
},
{
"offline": 51,
"station": "回龙观",
"online": 272
},
{
"offline": 156,
"station": "天通苑",
"online": 104
},
{
"offline": 47,
"station": "史各庄",
"online": 39
},
{
"offline": 29,
"station": "延寿",
"online": 0
},
{
"offline": 114,
"station": "昌平",
"online": 95
},
{
"offline": 28,
"station": "十三陵",
"online": 0
},
{
"offline": 41,
"station": "东小口",
"online": 41
},
{
"offline": 87,
"station": "小汤山",
"online": 124
},
{
"offline": 26,
"station": "阳坊",
"online": 213
},
{
"offline": 354,
"station": "松园",
"online": 0
}
]
现在有这么一组数据存在List里面，我想把这组数据变成下面这样的数据格式
{
"tiantongyuan": [
{
"offline": 156,
"station": "天通苑",
"online": 104
}
],
"dongxiaokou": [
{
"offline": 41,
"station": "东小口",
"online": 41
}
],
"xingshou": [
{
"offline": 44,
"station": "兴寿",
"online": 40
}
],
"beiliucun": [
{
"offline": 2,
"station": "北流村",
"online": 23
}
],
.......
}

Answer 1

//我理解你是想把List变成map，但是map里的键是Sting类型，值是List<实体>，但是下面我给出的是键是Sting类型，值是实体类型；
//-------------创建实体类-------------

@Data
public class OfStOn{
    private  int offline;
    private String station;
    private int online;
}

//-----------------------------------------------------------------
//-------------创建中文转拼音的类--------------

import net.sourceforge.pinyin4j.PinyinHelper;  
import net.sourceforge.pinyin4j.format.HanyuPinyinCaseType;  
import net.sourceforge.pinyin4j.format.HanyuPinyinOutputFormat;  
import net.sourceforge.pinyin4j.format.HanyuPinyinToneType;  
import net.sourceforge.pinyin4j.format.HanyuPinyinVCharType;  
import net.sourceforge.pinyin4j.format.exception.BadHanyuPinyinOutputFormatCombination;

public class ChineseTurnPinyin {
    /**  
     * getPingYin 
     * 返回中文拼音
     * @param src
     * @return String  
    */
    public static String getPingYin(String src) {  
        char[] t1 = null;  
        t1 = src.toCharArray();  
        String[] t2 = new String[t1.length];  
        HanyuPinyinOutputFormat t3 = new HanyuPinyinOutputFormat();  

        t3.setCaseType(HanyuPinyinCaseType.LOWERCASE);  
        t3.setToneType(HanyuPinyinToneType.WITHOUT_TONE);  
        t3.setVCharType(HanyuPinyinVCharType.WITH_V);  
        String t4 = "";  
        int t0 = t1.length;  
        try {  
            for (int i = 0; i < t0; i++) {  
                // 判断是否为汉字字符  
                if (java.lang.Character.toString(t1[i]).matches(  
                        "[\\u4E00-\\u9FA5]+")) {  
                    t2 = PinyinHelper.toHanyuPinyinStringArray(t1[i], t3);  
                    t4 += t2[0];  
                } else  
                    t4 += java.lang.Character.toString(t1[i]);  
            }  
            // System.out.println(t4);  
            return t4;  
        } catch (BadHanyuPinyinOutputFormatCombination e1) {  
            e1.printStackTrace();  
        }  
        return t4;  
    }

}

//---------------------------------------------------------------------
//--------实际转换的代码------------------

public HashMap<String,OfStOn> turnListToMap(List<OfStOn> ofstonList){
    HashMap<String,OfStOn> ofstonMap = new HashMap<String,OfStOn>();
    String key ="";
    OfStOn  ofston = new OfStOn();
    for(int i ;i<ofston.size();i++){
        ofston=ofston.get(i);
        key = ChineseTurnPinyin.getPingYin(ofston.getStation());
        ofstonMap.put(key,ofston);
    }
    return ofstonMap;
}