Following up for #3440 (1792 fix remote spec handling and hash calculation) (#3826)

* This patch fixes the bug that we cannot access to remote files when checking file updates.
Following up #3440, supporting auth.

* 1792 fix remote spec handling and hash calculation (#3440)

(cherry picked from commit 2a2eefe93d81b8d253745b8adb002ab2cb9eee04)

* fix detecting remote file / local file logic while finding the hash file, taking care of IllegalArgumentException for local files.

* add testcase

modules/openapi-generator-maven-plugin/examples/java-client.xml

@@ -17,6 +17,7 @@
                 <!-- /RELEASE_VERSION -->
                 <executions>
                     <execution>
+                        <id>default</id>
                         <goals>
                             <goal>generate</goal>
                         </goals>
@@ -39,6 +40,36 @@
                             <library>jersey2</library>
                         </configuration>
                     </execution>
+                    <execution>
+                        <id>remote</id>
+                        <phase>generate-sources</phase>
+                        <goals>
+                            <goal>generate</goal>
+                        </goals>
+                        <configuration>
+                            <!-- specify the swagger yaml -->
+                            <inputSpec>https://raw.githubusercontent.com/OpenAPITools/openapi-generator/master/modules/openapi-generator/src/test/resources/2_0/petstore.yaml</inputSpec>
+
+                            <!-- target to generate java client code -->
+                            <generatorName>java</generatorName>
+
+                            <!-- hint: if you want to generate java server code, e.g. based on Spring Boot,
+                                 you can use the following target: <generatorName>spring</generatorName> -->
+
+                            <!-- pass any necessary config options -->
+                            <configOptions>
+                                <dateLibrary>joda</dateLibrary>
+                            </configOptions>
+
+                            <!-- override the default library to jersey2 -->
+                            <library>jersey2</library>
+
+                            <output>${project.build.directory}/generated-sources/remote-openapi</output>
+                            <apiPackage>remote.org.openapitools.client.api</apiPackage>
+                            <modelPackage>remote.org.openapitools.client.model</modelPackage>
+                            <invokerPackage>remote.org.openapitools.client</invokerPackage>
+                        </configuration>
+                    </execution>
                 </executions>
             </plugin>
             <plugin>

modules/openapi-generator-maven-plugin/src/main/java/org/openapitools/codegen/plugin/CodeGenMojo.java

@@ -20,7 +20,18 @@ package org.openapitools.codegen.plugin;
 import static org.apache.commons.lang3.StringUtils.isNotEmpty;
 import static org.openapitools.codegen.config.CodegenConfiguratorUtils.*;
 
+import io.swagger.v3.parser.core.models.AuthorizationValue;
 import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.nio.channels.Channels;
+import java.nio.channels.FileChannel;
+import java.nio.channels.ReadableByteChannel;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -42,6 +53,7 @@ import org.openapitools.codegen.ClientOptInput;
 import org.openapitools.codegen.CodegenConfig;
 import org.openapitools.codegen.CodegenConstants;
 import org.openapitools.codegen.DefaultGenerator;
+import org.openapitools.codegen.auth.AuthParser;
 import org.openapitools.codegen.config.CodegenConfigurator;
 import org.openapitools.codegen.config.GlobalSettings;
 import org.sonatype.plexus.build.incremental.BuildContext;
@@ -429,7 +441,7 @@ public class CodeGenMojo extends AbstractMojo {
                 if (inputSpecFile.exists()) {
                     File storedInputSpecHashFile = getHashFile(inputSpecFile);
                     if(storedInputSpecHashFile.exists()) {
-                        String inputSpecHash = Files.asByteSource(inputSpecFile).hash(Hashing.sha256()).toString();
+                        String inputSpecHash = calculateInputSpecHash(inputSpecFile);
                         String storedInputSpecHash = Files.asCharSource(storedInputSpecHashFile, Charsets.UTF_8).read();
                         if (inputSpecHash.equals(storedInputSpecHash)) {
                             getLog().info(
@@ -720,12 +732,7 @@ public class CodeGenMojo extends AbstractMojo {
 
             // Store a checksum of the input spec
             File storedInputSpecHashFile = getHashFile(inputSpecFile);
-            ByteSource inputSpecByteSource =
+            String inputSpecHash = calculateInputSpecHash(inputSpecFile);
-                inputSpecFile.exists()
-                    ? Files.asByteSource(inputSpecFile)
-                    : CharSource.wrap(ClasspathHelper.loadFileFromClasspath(inputSpecFile.toString().replaceAll("\\\\","/")))
-                        .asByteSource(Charsets.UTF_8);
-            String  inputSpecHash =inputSpecByteSource.hash(Hashing.sha256()).toString();
 
             if (storedInputSpecHashFile.getParent() != null && !new File(storedInputSpecHashFile.getParent()).exists()) {
                 File parent = new File(storedInputSpecHashFile.getParent());
@@ -746,8 +753,75 @@ public class CodeGenMojo extends AbstractMojo {
         }
     }
 
+    /**
+     * Calculate openapi specification file hash. If specification is hosted on remote resource it is downloaded first
+     *
+     * @param inputSpecFile - Openapi specification input file to calculate it's hash.
+     *                        Does not taken into account if input spec is hosted on remote resource
+     * @return openapi specification file hash
+     * @throws IOException
+     */
+    private String calculateInputSpecHash(File inputSpecFile) throws IOException {
+
+        URL inputSpecRemoteUrl = inputSpecRemoteUrl();
+
+        File inputSpecTempFile = inputSpecFile;
+
+        if (inputSpecRemoteUrl != null) {
+            inputSpecTempFile = File.createTempFile("openapi-spec", ".tmp");
+
+            URLConnection conn = inputSpecRemoteUrl.openConnection();
+            if (isNotEmpty(auth)) {
+                List<AuthorizationValue> authList = AuthParser.parse(auth);
+                for (AuthorizationValue auth : authList) {
+                    conn.setRequestProperty(auth.getKeyName(), auth.getValue());
+                }
+            }
+            ReadableByteChannel readableByteChannel = Channels.newChannel(conn.getInputStream());
+
+            FileOutputStream fileOutputStream = new FileOutputStream(inputSpecTempFile);
+            FileChannel fileChannel = fileOutputStream.getChannel();
+
+            fileChannel.transferFrom(readableByteChannel, 0, Long.MAX_VALUE);
+        }
+
+        ByteSource inputSpecByteSource =
+                inputSpecTempFile.exists()
+                        ? Files.asByteSource(inputSpecTempFile)
+                        : CharSource.wrap(ClasspathHelper.loadFileFromClasspath(inputSpecTempFile.toString().replaceAll("\\\\","/")))
+                        .asByteSource(Charsets.UTF_8);
+
+        return inputSpecByteSource.hash(Hashing.sha256()).toString();
+    }
+
+    /**
+     * Try to parse inputSpec setting string into URL
+     * @return A valid URL or null if inputSpec is not a valid URL
+     */
+    private URL inputSpecRemoteUrl(){
+        try {
+            return new URI(inputSpec).toURL();
+        } catch (URISyntaxException | MalformedURLException | IllegalArgumentException e) {
+            return null;
+        }
+    }
+
+    /**
+     * Get specification hash file
+     * @param inputSpecFile - Openapi specification input file to calculate it's hash.
+     *                        Does not taken into account if input spec is hosted on remote resource
+     * @return a file with previously calculated hash
+     */
     private File getHashFile(File inputSpecFile) {
-        return new File(output.getPath() + File.separator + ".openapi-generator" + File.separator + inputSpecFile.getName() + ".sha256");
+        String name = inputSpecFile.getName();
+
+        URL url = inputSpecRemoteUrl();
+        if (url != null) {
+            String[] segments = url.getPath().split("/");
+            name = Files.getNameWithoutExtension(segments[segments.length - 1]);
+        }
+
+        return new File(output.getPath() + File.separator + ".openapi-generator" + File.separator + name + ".sha256");
     }
 
     private String getCompileSourceRoot() {
@@ -757,8 +831,7 @@ public class CodeGenMojo extends AbstractMojo {
         final String sourceFolder =
                 sourceFolderObject == null ? "src/main/java" : sourceFolderObject.toString();
 
-        String sourceJavaFolder = output.toString() + "/" + sourceFolder;
+        return output.toString() + "/" + sourceFolder;
-        return sourceJavaFolder;
     }
 
     private void addCompileSourceRootIfConfigured() {
@@ -803,4 +876,4 @@ public class CodeGenMojo extends AbstractMojo {
             }
         }
     }
-}
+}