java - HashMap<> 错误。类型开始非法

Question

每当我尝试编译这个函数时，它都会在第 10 行给出错误--> ErrorMessage : CandidateCode.java.10: 静态 HashMap 类型的非法开始 hm = new HashMap<>(); 1 个错误我试图在网站的编译器上编译它，但是当我使用 netbeans 时它工作得很好。

import java.util.*;

public class CandidateCode {

    static int rep, total = 0, sum = 0, i = 0, j = 0;
    static HashMap<Integer, Integer> hm = new HashMap<>();
    static ArrayList<Integer> al;

    public static int DistributingMedals(int input1, int[] input2, int[] input3, 
                                         int[] input4, int input5) {

        //Write code here
        for (i = 0; i < input1; i++) {
            int start = input3[i];
            int end = input4[i];
            int count = input2[i];
            for (j = start; j <= end; j++) {
                try {
                    sum = hm.get(j);
                } catch (Exception e) {
                    e.getMessage();
                    sum = 0;
                }
                sum = sum + count;
                hm.put(j, sum);
            }
        }
        int chk = 0;
        Collection<Integer> valcol = hm.values();
        casper:
        while (chk < valcol.size()) {
            for (int max : valcol) {
                total = max + total;
                if (total > input5) {
                    al = new ArrayList(hm.keySet());
                    Object obj = al.get(chk);
                    rep = (Integer) obj;
                    break casper;
                }
                chk++;
            }
        }
        return rep;
    }
}

Answer 1

您的java编译器版本低于1.7 。 <>仅允许在 1.7+ 中。更改项目属性并使用 1.7+ 进行编译或将代码更改为:

static HashMap<Integer, Integer> hm = new HashMap<Integer,Integer>();

注意:如何检查编译器版本。

1. Right click on the project.
2. properties.
3. java compiler