创建一个组件

AreaData

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * 初始化全局数据
 *
 * @Package_Name 
 * @Author 
 * @TIME
 * @Version
 */
@Component
public class AreaData implements CommandLineRunner {
    private static final Logger logger = LoggerFactory.getLogger(AreaData.class);

    @Autowired
    private Service service;

    public static Map<String, String> map;

    @Override
    public void run(String... args) {
        logger.info("***************开始加载数据***************");
        List<String> strings = service.query();
        map = strings.stream().collect(Collectors.toMap(e -> {
            String[] s = e.split("_");
            return s[s.length - 1];
        }, s -> s, (oldValue, newValue) -> oldValue));
        logger.info("***************结束加载数据***************");
    }
}

代码示意

 map = strings.stream().collect(Collectors.toMap(e -> {
            String[] s = e.split("_");
            return s[s.length - 1];
        }, s -> s, (oldValue, newValue) -> oldValue));

        该段为 List<String> 转 Map<String, String>

        toMap 中第三个参数为 出现重复 key 的处理方式：保留旧的

        出现重复键会抛异常（非法状态异常）：IllegalStateException

重点

@Component 注解不能忘

                                                                Leslie Lee 随笔