使用Java实现一个解析CURL脚本小工具

curl --location --request POST 'https://cainiao-inc.com?param_1=value_1&param_2=value_2' \
--header 'Cookie: USER_COOKIE' \
--header 'Content-Type: application/json' \
--data-raw '{
    "appName": "link",
    "apiId": "TEST_API",
    "content": {
        "address": "Cainiao Home",
        "city": "Hangzhou"
    }
}'

public class CurlParserUtil {
    /**
     * 该方法是用来解析CURL的入口。
     *
     * @param curl 输入的CURL文本字符串
     * @return 返回解析后生成的CURL实体对象
     */
    public static CurlEntity parse(String curl) {
        CurlEntity entity = CurlEntity.builder().build();
        ICurlHandler<CurlEntity, String> handlerChain = CurlHandlerChain.init();
 
        // 如需扩展其他解析器，继续往链表中add即可
        handlerChain.next(new UrlPathHandler())
                .next(new UrlParamsHandler())
                .next(new HttpMethodHandler())
                .next(new HeaderHandler())
                .next(new HttpBodyHandler());
 
        handlerChain.handle(entity, curl);
        return entity;
    }
}

@Data
@Builder
public class CurlEntity {
    /**
     * URL路径
     */
    private String url;
 
    /**
     * 请求方法类型
     */
    private Method method;
 
    /**
     * URL参数
     */
    private Map<String, String> urlParams;
 
    /**
     * header参数
     */
    private Map<String, String> headers;
 
    /**
     * 请求体
     */
    private JSONObject body;
 
    public enum Method {
        GET,
        POST,
        PUT,
        DELETE
    }
}

public interface ICurlHandler<R, S> {
 
    ICurlHandler<CurlEntity, String> next(ICurlHandler<CurlEntity, String> handler);
 
    void handle(CurlEntity entity, String curl);
}

public abstract class CurlHandlerChain implements ICurlHandler<CurlEntity, String> {
 
    ICurlHandler<CurlEntity, String> next;
 
    @Override
    public ICurlHandler<CurlEntity, String> next(ICurlHandler<CurlEntity, String> handler) {
        this.next = handler;
        return this.next;
    }
 
    @Override
    public abstract void handle(CurlEntity entity, String curl);
 
    /**
     * for subclass call
     */
    protected void nextHandle(CurlEntity curlEntity, String curl) {
        if (next != null) {
            next.handle(curlEntity, curl);
        }
    }
 
    protected void validate(String curl) {
        if (StringUtils.isBlank(curl)) {
            throw new IllegalArgumentException("Curl script is empty");
        }
 
        Matcher matcher = CURL_BASIC_STRUCTURE_PATTERN.matcher(curl);
        if (!matcher.find()) {
            throw new IllegalArgumentException("Curl script is invalid");
        }
    }
 
    public static CurlHandlerChain init() {
        return new CurlHandlerChain() {
            @Override
            public void handle(CurlEntity entity, String curl) {
                this.validate(curl);
 
                // 替换掉可能存在的转译(字符串中的空白字符，包括空格、换行符和制表符...)
                curl = curl.replace("\\", "")
                        .replace("\n", "")
                        .replace("\t", "");
 
                if (next != null) {
                    next.handle(entity, curl);
                }
            }
        };
    }
 
    public void log(Object... logParams) {
        // Write log for subclass extensions
    }
}

public class UrlPathHandler extends CurlHandlerChain {
 
    @Override
    public void handle(CurlEntity entity, String curl) {
        String url = parseUrlPath(curl);
        entity.setUrl(url);
 
        this.log(url);
        super.nextHandle(entity, curl);
    }
 
    /**
     * 该方法用于解析URL路径。
     *
     * @param curl 需要解析的URL，以字符串形式给出
     * @return URL中的路径部分。如果找不到，将返回null
     */
    private String parseUrlPath(String curl) {
        Matcher matcher = CurlPatternConstants.URL_PATH_PATTERN.matcher(curl);
        if (matcher.find()) {
            return matcher.group(1) != null ? matcher.group(1) : matcher.group(3);
        }
        return null;
    }
 
    @Override
    public void log(Object... logParams) {
        LogPrinter.info("UrlPathHandler execute: url={}", logParams);
    }
}

public class HttpMethodHandler extends CurlHandlerChain {
 
    @Override
    public void handle(CurlEntity entity, String curl) {
        CurlEntity.Method method = parseMethod(curl);
        entity.setMethod(method);
 
        this.log(method);
        super.nextHandle(entity, curl);
    }
 
    private CurlEntity.Method parseMethod(String curl) {
        Matcher matcher = CurlPatternConstants.HTTP_METHOD_PATTERN.matcher(curl);
        Matcher defaultMatcher = CurlPatternConstants.DEFAULT_HTTP_METHOD_PATTERN.matcher(curl);
        if (matcher.find()) {
            String method = matcher.group(1);
            return CurlEntity.Method.valueOf(method.toUpperCase());
        } else if (defaultMatcher.find()) {
            // 如果命令中包含 -d 或 --data，没有明确请求方法，默认为 POST
            return CurlEntity.Method.POST;
        } else {
            // 没有明确指定请求方法，默认为 GET
            return CurlEntity.Method.GET;
        }
    }
 
    @Override
    public void log(Object... logParams) {
        LogPrinter.info("HttpMethodHandler execute: method={}", logParams);
    }
}

public class UrlParamsHandler extends CurlHandlerChain {
 
    @Override
    public void handle(CurlEntity entity, String curl) {
        String url = extractUrl(curl);
        Map<String, String> urlParams = parseUrlParams(url);
        entity.setUrlParams(urlParams);
 
        this.log(urlParams);
        super.nextHandle(entity, curl);
    }
 
    private String extractUrl(String curl) {
        Matcher matcher = CurlPatternConstants.URL_PARAMS_PATTERN.matcher(curl);
        if (matcher.find()) {
            return matcher.group(1);
        }
        return null;
    }
 
    private Map<String, String> parseUrlParams(String url) {
        if (StringUtils.isBlank(url)) {
            return Collections.emptyMap();
        }
 
        Map<String, String> urlParams = new HashMap<>();
        // 提取URL的查询参数部分
        String[] urlParts = url.split("\\?");
        if (urlParts.length > 1) {
            // 只处理存在查询参数的情况
            String query = urlParts[1];
            // 解析查询参数到Map
            String[] pairs = query.split("&");
            for (String pair : pairs) {
                int idx = pair.indexOf("=");
                if (idx != -1 && idx < pair.length() - 1) {
                    String key = pair.substring(0, idx);
                    String value = pair.substring(idx + 1);
                    urlParams.put(key, value);
                } else {
                    // 存在无值的参数时
                    urlParams.put(pair, null);
                }
            }
        }
        return urlParams;
    }
 
    @Override
    public void log(Object... logParams) {
        LogPrinter.info("UrlParamsHandler execute: urlParams={}", logParams);
    }
}

public class HeaderHandler extends CurlHandlerChain{
    
    @Override
    public void handle(CurlEntity entity, String curl) {
        Map<String, String> headers = parseHeaders(curl);
        entity.setHeaders(headers);
 
        this.log(headers);
        super.nextHandle(entity, curl);
    }
 
    private Map<String, String> parseHeaders(String curl) {
        if (StringUtils.isBlank(curl)) {
            return Collections.emptyMap();
        }
 
        Matcher matcher = CurlPatternConstants.CURL_HEADERS_PATTERN.matcher(curl);
        Map<String, String> headers = new HashMap<>();
        while (matcher.find()) {
            String header = matcher.group(1);
            String[] headerKeyValue = header.split(":", 2);
            if (headerKeyValue.length == 2) {
                // 去除键和值的首尾空白字符
                headers.put(headerKeyValue[0].trim(), headerKeyValue[1].trim());
            }
        }
 
        return headers;
    }
 
    @Override
    public void log(Object... logParams) {
        LogPrinter.info("HeaderHandler execute: headers={}", logParams);
    }
}

public class HttpBodyHandler extends CurlHandlerChain {
    @Override
    public void handle(CurlEntity entity, String curl) {
        JSONObject body = parseBody(curl);
        entity.setBody(body);
 
        this.log(body);
        super.nextHandle(entity, curl);
    }
 
    private JSONObject parseBody(String curl) {
        Matcher formMatcher = CurlPatternConstants.HTTP_FROM_BODY_PATTERN.matcher(curl);
        if (formMatcher.find()) {
            return parseFormBody(formMatcher);
        }
 
        Matcher urlencodeMatcher = CurlPatternConstants.HTTP_URLENCODE_BODY_PATTERN.matcher(curl);
        if (urlencodeMatcher.find()) {
            return parseUrlEncodeBody(urlencodeMatcher);
        }
 
        Matcher rawMatcher = CurlPatternConstants.HTTP_ROW_BODY_PATTERN.matcher(curl);
        if (rawMatcher.find()) {
            return parseRowBody(rawMatcher);
        }
 
        Matcher defaultMatcher = CurlPatternConstants.DEFAULT_HTTP_BODY_PATTERN.matcher(curl);
        if (defaultMatcher.find()) {
            return parseDefaultBody(defaultMatcher);
        }
 
        return new JSONObject();
    }
 
    private JSONObject parseDefaultBody(Matcher defaultMatcher) {
        String bodyStr = "";
        if (defaultMatcher.group(1) != null) {
            // 单引号包裹的数据
            bodyStr = defaultMatcher.group(1);
        } else if (defaultMatcher.group(2) != null) {
            // 双引号包裹的数据
            bodyStr = defaultMatcher.group(2);
        } else {
            // 无引号的数据
            bodyStr = defaultMatcher.group(3);
        }
 
        // 判断是否是json结构
        if (isJSON(bodyStr)) {
            return JSONObject.parseObject(bodyStr);
        }
 
        // 特殊Case: username=test&password=secret
        Matcher kvMatcher = CurlPatternConstants.DEFAULT_HTTP_BODY_PATTERN_KV.matcher(bodyStr);
        return kvMatcher.matches() ? parseKVBody(bodyStr) : new JSONObject();
    }
 
    private JSONObject parseKVBody(String kvBodyStr) {
        JSONObject json = new JSONObject();
        String[] pairs = kvBodyStr.split("&");
        for (String pair : pairs) {
            int idx = pair.indexOf("=");
            String key = URLDecoder.decode(pair.substring(0, idx), StandardCharsets.UTF_8);
            String value = URLDecoder.decode(pair.substring(idx + 1), StandardCharsets.UTF_8);
            json.put(key, value);
        }
        return json;
    }
 
    private JSONObject parseFormBody(Matcher formMatcher) {
        JSONObject formData = new JSONObject();
 
        // 重置指针匹配的位置
        formMatcher.reset();
        while (formMatcher.find()) {
            // 提取表单项
            String formItem = formMatcher.group(1) != null ? formMatcher.group(1) : formMatcher.group(2);
 
            // 分割键和值
            String[] keyValue = formItem.split("=", 2);
            if (keyValue.length == 2) {
                String key = keyValue[0];
                String value = keyValue[1];
 
                // 检测文件字段标记
                // PS: 理论上文件标记字段不需要支持
                if (value.startsWith("@")) {
                    // 只提取文件名，不读取文件内容
                    formData.put(key, value.substring(1));
                } else {
                    // 放入表单数据
                    formData.put(key, value);
                }
            }
        }
 
        return formData;
    }
 
    private JSONObject parseUrlEncodeBody(Matcher urlencodeMatcher) {
        JSONObject urlEncodeData = new JSONObject();
 
        // 重置指针匹配的位置
        urlencodeMatcher.reset();
        while (urlencodeMatcher.find()) {
            // 提取键值对字符串
            String keyValueEncoded = urlencodeMatcher.group(1);
 
            // 分隔键和值
            String[] keyValue = keyValueEncoded.split("=", 2);
            if (keyValue.length == 2) {
                String key = keyValue[0];
                String value = keyValue[1];
 
                // 对值进行URL解码
                String decodedValue = URLDecoder.decode(value, StandardCharsets.UTF_8);
 
                // 存入数据到JSON对象
                urlEncodeData.put(key, decodedValue);
            }
        }
 
        return urlEncodeData;
    }
 
    private JSONObject parseRowBody(Matcher rowMatcher) {
        String rawData = rowMatcher.group(1);
 
        if (isXML(rawData)) {
            // throw new IllegalArgumentException("Curl --data-raw content cant' be XML");
            return xml2json(rawData);
        }
 
        try {
            return JSON.parseObject(rawData);
        } catch (Exception e) {
            throw new IllegalArgumentException("Curl --data-raw content is not a valid JSON");
        }
    }
 
    private boolean isJSON(String jsonStr) {
        try {
            JSONObject.parseObject(jsonStr);
            return true;
        } catch (Exception e) {
            return false;
        }
    }
 
    public static boolean isXML(String xmlStr) {
        try {
            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
            factory.setFeature(SecurityConstants.DDD, true);
            factory.setFeature(SecurityConstants.EGE, false);
            factory.setFeature(SecurityConstants.EPE, false);
 
            DocumentBuilder builder = factory.newDocumentBuilder();
            InputSource is = new InputSource(new StringReader(xmlStr));
            builder.parse(is);
            return true;
        } catch (Exception e) {
            return false;
        }
    }
 
    private JSONObject xml2json(String xmlStr) {
        try {
            org.json.JSONObject orgJsonObj = XML.toJSONObject(xmlStr);
            String jsonString = orgJsonObj.toString();
            return JSON.parseObject(jsonString);
        } catch (JSONException e) {
            throw new LinkConsoleException("Curl --data-raw content xml2json error", e);
        }
    }
 
    @Override
    public void log(Object... logParams) {
        LogPrinter.info("HttpBodyHandler execute: body={}", logParams);
    }
}

public interface CurlPatternConstants {
 
    /**
     * CURL基本结构校验
     */
    Pattern CURL_BASIC_STRUCTURE_PATTERN = Pattern.compile("^curl (\\S+)");
 
    /**
     * URL路径匹配
     */
    Pattern URL_PATH_PATTERN =
            Pattern.compile("(?:\\s|^)(?:'|\")?(https?://[^?\\s'\"]*)(?:\\?[^\\s'\"]*)?(?:'|\")?(?:\\s|$)");
 
    /**
     * 请求参数列表匹配
     */
    Pattern URL_PARAMS_PATTERN = Pattern.compile("(?:\\s|^)(?:'|\")?(https?://[^\\s'\"]+)(?:'|\")?(?:\\s|$)");
 
    /**
     * HTTP请求方法匹配
     */
    //Pattern HTTP_METHOD_PATTERN = Pattern.compile("(?:-X|--request)\\s+(\\S+)");
    Pattern HTTP_METHOD_PATTERN = Pattern.compile("curl\\s+[^\\s]*\\s+(?:-X|--request)\\s+'?(GET|POST)'?");
 
    /**
     * 默认HTTP请求方法匹配
     */
    Pattern DEFAULT_HTTP_METHOD_PATTERN = Pattern.compile(".*\\s(-d|--data|--data-binary)\\s.*");
 
    /**
     * 请求头匹配
     */
    Pattern CURL_HEADERS_PATTERN = Pattern.compile("(?:-H|--header)\\s+'(.*?:.*?)'");
 
    /**
     * -d/--data 请求体匹配
     */
    Pattern DEFAULT_HTTP_BODY_PATTERN = Pattern.compile("(?:--data|-d)\\s+(?:'([^']*)'|\"([^\"]*)\"|(\\S+))", Pattern.DOTALL);
    Pattern DEFAULT_HTTP_BODY_PATTERN_KV = Pattern.compile("^([^=&]+=[^=&]+)(?:&[^=&]+=[^=&]+)*$", Pattern.DOTALL);
 
    /**
     * --data-raw 请求体匹配
     */
    Pattern HTTP_ROW_BODY_PATTERN = Pattern.compile("--data-raw '(.+?)'(?s)", Pattern.DOTALL);
 
    /**
     * --form 请求体匹配
     */
    Pattern HTTP_FROM_BODY_PATTERN = Pattern.compile("--form\\s+'(.*?)'|-F\\s+'(.*?)'");
 
 
    /**
     * --data-urlencode 请求体匹配
     */
    Pattern HTTP_URLENCODE_BODY_PATTERN = Pattern.compile("--data-urlencode\\s+'(.*?)'");
 
}

public class SecurityConstants {
    public static String DDD = "http://apache.org/xml/features/disallow-doctype-decl";
    public static String EGE = "http://xml.org/sax/features/external-general-entities";
    public static String EPE = "http://xml.org/sax/features/external-parameter-entities";
    public static String LED = "http://apache.org/xml/features/nonvalidating/load-external-dtd";
}