add custom PatchMethod class to use http PATCH requests with the Nextcloud SSO api

scripts/analysis/findbugs-results.txt

@@ -1 +1 @@
-460
+462

src/main/java/com/nextcloud/android/sso/InputStreamBinder.java

@@ -263,6 +263,20 @@ private HttpMethodBase buildMethod(NextcloudRequest request, Uri baseUri, InputS
                 }
                 break;
 
+            case "PATCH":
+                method = new PatchMethod(requestUrl);
+                if (requestBodyInputStream != null) {
+                    RequestEntity requestEntity = new InputStreamRequestEntity(requestBodyInputStream);
+                    ((PatchMethod) method).setRequestEntity(requestEntity);
+                } else if (request.getRequestBody() != null) {
+                    StringRequestEntity requestEntity = new StringRequestEntity(
+                        request.getRequestBody(),
+                        CONTENT_TYPE_APPLICATION_JSON,
+                        CHARSET_UTF8);
+                    ((PatchMethod) method).setRequestEntity(requestEntity);
+                }
+                break;
+
             case "PUT":
                 method = new PutMethod(requestUrl);
                 if (requestBodyInputStream != null) {
@@ -298,8 +312,8 @@ private HttpMethodBase buildMethod(NextcloudRequest request, Uri baseUri, InputS
                 break;
 
             case "HEAD":
-                 method = new HeadMethod(requestUrl);
-                 break;
+                method = new HeadMethod(requestUrl);
+                break;
 
             default:
                 throw new UnsupportedOperationException(EXCEPTION_UNSUPPORTED_METHOD);

src/main/java/com/nextcloud/android/sso/PatchMethod.java

@@ -0,0 +1,118 @@
+/*
+ * Nextcloud SingleSignOn
+ *
+ * @author Timo Triebensky
+ * Copyright (C) 2021 Timo Triebensky
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * More information here: https://github.com/abeluck/android-streams-ipc
+ *
+ * ====================================================================
+ *
+ * The required methods of this class are copied and customized from PostMethod.
+ */
+
+package com.nextcloud.android.sso;
+
+import org.apache.commons.httpclient.methods.ByteArrayRequestEntity;
+import org.apache.commons.httpclient.methods.EntityEnclosingMethod;
+import org.apache.commons.httpclient.methods.PostMethod;
+import org.apache.commons.httpclient.methods.RequestEntity;
+import org.apache.commons.httpclient.util.EncodingUtil;
+
+import java.util.Vector;
+
+public class PatchMethod extends PostMethod {
+
+    /**
+     * The buffered request body consisting of <code>NameValuePair</code>s.
+     */
+    private Vector params = new Vector();
+
+    /**
+     * No-arg constructor.
+     */
+    public PatchMethod() {
+        super();
+    }
+
+    /**
+     * Constructor specifying a URI.
+     *
+     * @param uri either an absolute or relative URI
+     */
+    public PatchMethod(String uri) {
+        super(uri);
+    }
+
+    /**
+     * Returns <tt>"PATCH"</tt>.
+     *
+     * @return <tt>"PATCH"</tt>
+     * @since 2.0
+     */
+    @Override
+    public String getName() {
+        return "PATCH";
+    }
+
+    /**
+     * Returns <tt>true</tt> if there is a request body to be sent.
+     *
+     * @return boolean
+     * @since 2.0beta1
+     */
+    protected boolean hasRequestContent() {
+        if (!this.params.isEmpty()) {
+            return true;
+        } else {
+            return super.hasRequestContent();
+        }
+    }
+
+    /**
+     * Clears request body.
+     *
+     * @since 2.0beta1
+     */
+    protected void clearRequestBody() {
+        this.params.clear();
+        super.clearRequestBody();
+    }
+
+    /**
+     * Generates a request entity from the patch parameters, if present.  Calls {@link
+     * EntityEnclosingMethod#generateRequestBody()} if parameters have not been set.
+     *
+     * @since 3.0
+     */
+    protected RequestEntity generateRequestEntity() {
+        if (!this.params.isEmpty()) {
+            // Use a ByteArrayRequestEntity instead of a StringRequestEntity.
+            // This is to avoid potential encoding issues.  Form url encoded strings
+            // are ASCII by definition but the content type may not be.  Treating the content
+            // as bytes allows us to keep the current charset without worrying about how
+            // this charset will effect the encoding of the form url encoded string.
+            String content = EncodingUtil.formUrlEncode(getParameters(), getRequestCharSet());
+            ByteArrayRequestEntity entity = new ByteArrayRequestEntity(
+                EncodingUtil.getAsciiBytes(content),
+                FORM_URL_ENCODED_CONTENT_TYPE
+            );
+            return entity;
+        } else {
+            return super.generateRequestEntity();
+        }
+    }
+}