RefUtils.java

package io.swagger.parser.util;

import io.swagger.models.auth.AuthorizationValue;
import io.swagger.models.refs.RefFormat;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;

import java.io.FileInputStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;

public class RefUtils {

    public static String computeDefinitionName(String ref) {

        final String[] refParts = ref.split("#/");

        if (refParts.length > 2) {
            throw new RuntimeException("Invalid ref format: " + ref);
        }

        final String file = refParts[0];
        final String definitionPath = refParts.length == 2 ? refParts[1] : null;


        String plausibleName;

        if (definitionPath != null) { //the name will come from the last element of the definition path
            final String[] jsonPathElements = definitionPath.split("/");
            plausibleName = jsonPathElements[jsonPathElements.length - 1];
        } else { //no definition path, so we must come up with a name from the file
            final String[] filePathElements = file.split("/");
            plausibleName = filePathElements[filePathElements.length - 1];

            final String[] split = plausibleName.split("\\.");
            plausibleName = split[0];
        }

        return plausibleName;
    }

    public static boolean isAnExternalRefFormat(RefFormat refFormat) {
        return refFormat == RefFormat.URL || refFormat == RefFormat.RELATIVE;
    }


    public static String readExternalUrlRef(String file, RefFormat refFormat, List<AuthorizationValue> auths,
                                         String rootPath) {

        if (!RefUtils.isAnExternalRefFormat(refFormat)) {
            throw new RuntimeException("Ref is not external");
        }

        String result;

        try {
            if (refFormat == RefFormat.URL) {
                result = RemoteUrl.urlToString(file, auths);
            } else {
                //its assumed to be a relative ref
                String url = buildUrl(rootPath, file);

                return readExternalRef(url, RefFormat.URL, auths, null);
            }
        } catch (Exception e) {
            throw new RuntimeException("Unable to load " + refFormat + " ref: " + file, e);
        }

        return result;

    }

    public static String buildUrl(String rootPath, String relativePath) {
        String[] rootPathParts = rootPath.split("/");
        String [] relPathParts = relativePath.split("/");

        if(rootPath == null || relativePath == null) {
            return null;
        }

        int trimRoot = 0;
        int trimRel = 0;

        if(!"".equals(rootPathParts[rootPathParts.length - 1])) {
            trimRoot = 1;
        }
        for(int i = 0; i < rootPathParts.length; i++) {
            if("".equals(rootPathParts[i])) {
                trimRel += 1;
            }
            else {
                break;
            }
        }
        for(int i = 0; i < relPathParts.length; i ++) {
            if(".".equals(relPathParts[i])) {
                trimRel += 1;
            }
            else if ("..".equals(relPathParts[i])) {
                trimRel += 1;
            }
        }

        String [] outputParts = new String[rootPathParts.length + relPathParts.length - trimRoot - trimRel];
        System.arraycopy(rootPathParts, 0, outputParts, 0, rootPathParts.length - trimRoot);
        System.arraycopy(relPathParts,
                trimRel,
                outputParts,
                rootPathParts.length - trimRoot + trimRel - 1,
                relPathParts.length - trimRel);

        return StringUtils.join(outputParts, "/");
    }

    public static String readExternalRef(String file, RefFormat refFormat, List<AuthorizationValue> auths,
                                         Path parentDirectory) {

        if (!RefUtils.isAnExternalRefFormat(refFormat)) {
            throw new RuntimeException("Ref is not external");
        }

        String result;

        try {
            if (refFormat == RefFormat.URL) {
                result = RemoteUrl.urlToString(file, auths);
            } else {
                //its assumed to be a relative file ref
                final Path pathToUse = parentDirectory.resolve(file).normalize();

                if(Files.exists(pathToUse)) {
                    result = IOUtils.toString(new FileInputStream(pathToUse.toFile()), "UTF-8");
                } else {
                    result = ClasspathHelper.loadFileFromClasspath(file);
                }

            }
        } catch (Exception e) {
            throw new RuntimeException("Unable to load " + refFormat + " ref: " + file, e);
        }

        return result;

    }
}