import org.springframework.boot.CommandLineRunner;
import org.springframework.core.env.ConfigurableEnvironment;
import org.springframework.core.env.EnumerablePropertySource;
import org.springframework.core.env.MutablePropertySources;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;

@Component
public class StartProcessor implements CommandLineRunner {

    @Resource
    private ConfigurableEnvironment springEnv;

    @Override
    public void run(String... strings) {

        MutablePropertySources propertySources = springEnv.getPropertySources();

        // 獲取所有配置
        Map<String, String> props = StreamSupport.stream(propertySources.spliterator(), false)
                .filter(ps -> ps instanceof EnumerablePropertySource)
                .map(ps -> ((EnumerablePropertySource<?>) ps).getPropertyNames())
                .flatMap(Arrays::stream)
                .distinct()
                .collect(Collectors.toMap(Function.identity(), springEnv::getProperty));

        // key 和 value 之間的最小間隙
        int interval = 20;
        int max = props.keySet().stream().max(Comparator.comparingInt(String::length)).orElse("").length();

        // 打印
        props.keySet().stream() .sorted()    .forEach(k -> {
            int i = max - k.length() + interval;
            String join = String.join("", Collections.nCopies(i, " "));
            System.out.printf("%s%s%s%n", k, join, props.get(k));
        });

    }
}