YmlUtils.castProperties("application-test.yml");

package com.test.utils;
 
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.*;
 
/**
 * Yaml 配置文件轉(zhuǎn) Properties 配置文件工具類
 * @author https://zyqok.blog.csdn.net/
 * @since 2021/08/24
 */
public class YmlUtils {
 
    /**
     * 將 yml 文件轉(zhuǎn)化為 properties 文件
     *
     * @param ymlFileName 工程根目錄下（非resources目錄）的 yml 文件名稱（如：abc.yml）
     * @return List<Node> 每個(gè)Nyml 文件中每行對應(yīng)解析的數(shù)據(jù)
     */
    public static List<YmlNode> castProperties(String ymlFileName) {
        if (ymlFileName == null || ymlFileName.isEmpty() || !ymlFileName.endsWith(".yml")) {
            throw new RuntimeException("請輸入yml文件名稱?。?);
        }
        File ymlFile = new File(ymlFileName);
        if (!ymlFile.exists()) {
            throw new RuntimeException("工程根目錄下不存在 " + ymlFileName + "文件??！");
        }
        String fileName = ymlFileName.split(".yml", 2)[0];
        // 獲取文件數(shù)據(jù)
        String yml = read(ymlFile);
        List<YmlNode> nodeList = getNodeList(yml);
        // 去掉多余數(shù)據(jù)，并打印
        String str = printNodeList(nodeList);
        // 將數(shù)據(jù)寫入到 properties 文件中
        String propertiesName = fileName + ".properties";
        File file = new File(propertiesName);
        if (!file.exists()) {
            try {
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        try (FileWriter writer = new FileWriter(file)) {
            writer.write(str);
            writer.flush();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return nodeList;
    }
 
    /**
     * 將yml轉(zhuǎn)化為porperties文件，并獲取轉(zhuǎn)化后的鍵值對
     *
     * @param ymlFileName 工程根目錄下的 yml 文件名稱
     * @return 轉(zhuǎn)化后的 porperties 文件鍵值對Map
     */
    public static Map<String, String> getPropertiesMap(String ymlFileName) {
        Map<String, String> map = new HashMap<>();
        List<YmlNode> list = castProperties(ymlFileName);
        for (YmlNode node : list) {
            if (node.getKey().length() > 0) {
                map.put(node.getKey(), node.getValue());
            }
        }
        return map;
    }
 
    private static String read(File file) {
        if (Objects.isNull(file) || !file.exists()) {
            return "";
        }
        try (FileInputStream fis = new FileInputStream(file)) {
            byte[] b = new byte[(int) file.length()];
            fis.read(b);
            return new String(b, StandardCharsets.UTF_8);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return "";
    }
 
    private static String printNodeList(List<YmlNode> nodeList) {
        StringBuilder sb = new StringBuilder();
        for (YmlNode node : nodeList) {
            if (node.getLast().equals(Boolean.FALSE)) {
                continue;
            }
            if (node.getEmptyLine().equals(Boolean.TRUE)) {
                System.out.println();
                sb.append("\r\n");
                continue;
            }
            // 判斷是否有行級注釋
            if (node.getHeadRemark().length() > 0) {
                String s = "# " + node.getHeadRemark();
                System.out.println(s);
                sb.append(s).append("\r\n");
                continue;
            }
            // 判斷是否有行末注釋 (properties中注釋不允許末尾注釋，故而放在上面)
            if (node.getTailRemark().length() > 0) {
                String s = "# " + node.getTailRemark();
                System.out.println(s);
                sb.append(s).append("\r\n");
            }
            //
            String kv = node.getKey() + "=" + node.getValue();
            System.out.println(kv);
            sb.append(kv).append("\r\n");
        }
        return sb.toString();
    }
 
    private static List<YmlNode> getNodeList(String yml) {
        String[] lines = yml.split("\r\n");
        List<YmlNode> nodeList = new ArrayList<>();
        Map<Integer, String> keyMap = new HashMap<>();
        Set<String> keySet = new HashSet<>();
        for (String line : lines) {
            YmlNode node = getNode(line);
            if (node.getKey() != null && node.getKey().length() > 0) {
                int level = node.getLevel();
                if (level == 0) {
                    keyMap.clear();
                    keyMap.put(0, node.getKey());
                } else {
                    int parentLevel = level - 1;
                    String parentKey = keyMap.get(parentLevel);
                    String currentKey = parentKey + "." + node.getKey();
                    keyMap.put(level, currentKey);
                    node.setKey(currentKey);
                }
            }
            keySet.add(node.getKey() + ".");
            nodeList.add(node);
        }
        // 標(biāo)識是否最后一級
        for (YmlNode each : nodeList) {
            each.setLast(getNodeLast(each.getKey(), keySet));
        }
        return nodeList;
    }
 
    private static boolean getNodeLast(String key, Set<String> keySet) {
        if (key.isEmpty()) {
            return true;
        }
        key = key + ".";
        int count = 0;
        for (String each : keySet) {
            if (each.startsWith(key)) {
                count++;
            }
        }
        return count == 1;
    }
 
    private static YmlNode getNode(String line) {
        YmlNode node = new YmlNode();
        // 初始化默認(rèn)數(shù)據(jù)（防止NPE）
        node.setEffective(Boolean.FALSE);
        node.setEmptyLine(Boolean.FALSE);
        node.setHeadRemark("");
        node.setKey("");
        node.setValue("");
        node.setTailRemark("");
        node.setLast(Boolean.FALSE);
        node.setLevel(0);
        // 空行，不處理
        String trimStr = line.trim();
        if (trimStr.isEmpty()) {
            node.setEmptyLine(Boolean.TRUE);
            return node;
        }
        // 行注釋，不處理
        if (trimStr.startsWith("#")) {
            node.setHeadRemark(trimStr.replaceFirst("#", "").trim());
            return node;
        }
        // 處理值
        String[] strs = line.split(":", 2);
        // 拆分后長度為0的，屬于異常數(shù)據(jù)，不做處理
        if (strs.length == 0) {
            return node;
        }
        // 獲取鍵
        node.setKey(strs[0].trim());
        // 獲取值
        String value;
        if (strs.length == 2) {
            value = strs[1];
        } else {
            value = "";
        }
        // 獲取行末備注
        String tailRemark = "";
        if (value.contains(" #")) {
            String[] vs = value.split("#", 2);
            if (vs.length == 2) {
                value = vs[0];
                tailRemark = vs[1];
            }
        }
        node.setTailRemark(tailRemark.trim());
        node.setValue(value.trim());
        // 獲取當(dāng)前層級
        int level = getNodeLevel(line);
        node.setLevel(level);
        node.setEffective(Boolean.TRUE);
        return node;
    }
 
    private static int getNodeLevel(String line) {
        if (line.trim().isEmpty()) {
            return 0;
        }
        char[] chars = line.toCharArray();
        int count = 0;
        for (char c : chars) {
            if (c != ' ') {
                break;
            }
            count++;
        }
        return count / 2;
    }
}
 
class YmlNode {
 
    /** 層級關(guān)系 */
    private Integer level;
    /** 鍵 */
    private String key;
    /** 值 */
    private String value;
    /** 是否為空行 */
    private Boolean emptyLine;
    /** 當(dāng)前行是否為有效配置 */
    private Boolean effective;
    /** 頭部注釋（單行注釋） */
    private String headRemark;
    /** 末尾注釋 */
    private String tailRemark;
    /** 是否為最后一層配置 */
    private Boolean last;
 
    public Boolean getLast() {
        return last;
    }
 
    public void setLast(Boolean last) {
        this.last = last;
    }
 
    public Integer getLevel() {
        return level;
    }
 
    public void setLevel(Integer level) {
        this.level = level;
    }
 
    public String getKey() {
        return key;
    }
 
    public void setKey(String key) {
        this.key = key;
    }
 
    public String getValue() {
        return value;
    }
 
    public void setValue(String value) {
        this.value = value;
    }
 
    public Boolean getEmptyLine() {
        return emptyLine;
    }
 
    public void setEmptyLine(Boolean emptyLine) {
        this.emptyLine = emptyLine;
    }
 
    public Boolean getEffective() {
        return effective;
    }
 
    public void setEffective(Boolean effective) {
        this.effective = effective;
    }
 
    public String getHeadRemark() {
        return headRemark;
    }
 
    public void setHeadRemark(String headRemark) {
        this.headRemark = headRemark;
    }
 
    public String getTailRemark() {
        return tailRemark;
    }
 
    public void setTailRemark(String tailRemark) {
        this.tailRemark = tailRemark;
    }
 
}