Question

java取出list中相同的数据，并拼接

比如我有五个list,里面的数据是ID，name,subject,fen.四个字段，数据是这样的list1{"id":"1","name:"张三"","subject":"数学","fen":"80"}，list2{"id":"1","name:"张三"subject":"语文","fen":"90"}，list3{id":"2","name:"张三"","subject":"数学","fen":"60"}，list4{id":"1","name:"李四"","subject":"数学","fen":"80"}，根据list的中ID和name,确认list1和list2是需要的数据，取出来的结构应该是newlist{"id":"1","name:"张三"","subject":"数学 语文","fen":"80 90"}
最好直接上代码，写点备注，我能理解

Answer 1

import java.util.*;
import java.util.regex.*;
class Untitled {
	private static String getV(String input, String key){
		String reg = "([\"\']?)"+key+"\\1[:\\s]+([\"\']?)([^\"\']*)\\2";
		Pattern p = Pattern.compile(reg);
		Matcher m = p.matcher(input);
		while(m.find()){
			return m.group(3);
		}
		return "";
	}
	public static void main(String[] args) {
		String list1="{\"id\":\"1\",\"name\":\"张三\",\"subject\":\"数学\",\"fen\":\"80\"}";
		String list2 = "{\"id\":\"1\",\"name\":\"张三\",\"subject\":\"语文\",\"fen\":\"90\"}";
		String list3 = "{\"id\":\"2\",\"name\":\"张三\",\"subject\":\"数学\",\"fen\":\"60\"}";
		String list4 = "{\"id\":\"1\",\"name\":\"李四\",\"subject\":\"数学\",\"fen\":\"80\"}";


		String[] arr = {list1,list2,list3,list4};
		HashMap<String,String> map = new HashMap<String,String>();
		for(int i=0;i<arr.length;i++){
			String ai = arr[i];
			String id = getV(ai, "id");
			String name = getV(ai, "name");
			String key = id + name;
			if(null==map.get(key)){
				map.put(key, ai);
			}else{
				String prev = map.get(key);
				String subject1 = getV(prev, "subject");
				String fen1 = getV(prev, "fen");
				String subject2 = getV(ai, "subject");
				String fen2 = getV(ai, "fen");

				String s1 = "\"subject\":" + subject1 + " " + subject2 + "\"";
				String f1 = "\"fen\":" + fen1 + " " + fen2 + "\"";
				prev = prev.replaceAll("([\"\']?)subject\\1[:\\s]+([\"\']?)([^\"\']*)\\2",s1)
					.replaceAll("([\"\']?)fen\\1[:\\s]+([\"\']?)([^\"\']*)\\2",f1);
				map.put(key,prev);
			}
		}
		for (Map.Entry<String, String> entry : map.entrySet()) {
			System.out.println(entry.getValue());
		}  
	}
}