Add supplier based FileUpload

src/main/java/net/dv8tion/jda/api/utils/FileUpload.java

@@ -18,20 +18,24 @@
 
 import net.dv8tion.jda.api.utils.data.DataObject;
 import net.dv8tion.jda.internal.requests.Requester;
-import net.dv8tion.jda.internal.utils.BufferedRequestBody;
 import net.dv8tion.jda.internal.utils.Checks;
 import net.dv8tion.jda.internal.utils.EntityString;
 import net.dv8tion.jda.internal.utils.IOUtil;
+import net.dv8tion.jda.internal.utils.requestbody.DataSupplierBody;
+import net.dv8tion.jda.internal.utils.requestbody.TypedBody;
 import okhttp3.MediaType;
 import okhttp3.MultipartBody;
 import okhttp3.RequestBody;
+import okio.Okio;
+import okio.Source;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import java.io.*;
 import java.nio.file.Files;
 import java.nio.file.OpenOption;
 import java.nio.file.Path;
+import java.util.function.Supplier;
 
 /**
  * Represents a file that is intended to be uploaded to Discord for arbitrary requests.
@@ -43,16 +47,80 @@
 public class FileUpload implements Closeable, AttachedFile
 {
     private final InputStream resource;
+    private final Supplier<? extends Source> resourceSupplier;
     private String name;
-    private BufferedRequestBody body;
+    private TypedBody<?> body;
     private String description;
 
     protected FileUpload(InputStream resource, String name)
     {
         this.resource = resource;
+        this.resourceSupplier = null;
         this.name = name;
     }
 
+    protected FileUpload(Supplier<? extends Source> resourceSupplier, String name)
+    {
+        this.resourceSupplier = resourceSupplier;
+        this.resource = null;
+        this.name = name;
+    }
+
+    /**
+     * Creates a FileUpload that sources its data from the supplier.
+     * <br>The supplier <em>must</em> return a new stream on every call.
+     *
+     * <p>The streams are expected to always be at the beginning, when they are taken from the supplier.
+     * If the supplier returned the same stream instance, the reader would start at the wrong position when re-attempting a request.
+     *
+     * <p>When this supplier factory is used, {@link #getData()} will return a new instance on each call.
+     * It is the responsibility of the caller to close that stream.
+     *
+     * @param  name
+     *         The file name
+     * @param  supplier
+     *         The resource supplier, which returns a new stream on each call
+     *
+     * @throws IllegalArgumentException
+     *         If null is provided or the name is blank
+     *
+     * @return {@link FileUpload}
+     */
+    @Nonnull
+    public static FileUpload fromStreamSupplier(@Nonnull String name, @Nonnull Supplier<? extends InputStream> supplier)
+    {
+        Checks.notNull(supplier, "Supplier");
+        return fromSourceSupplier(name, () -> Okio.source(supplier.get()));
+    }
+
+    /**
+     * Creates a FileUpload that sources its data from the supplier.
+     * <br>The supplier <em>must</em> return a new stream on every call.
+     *
+     * <p>The streams are expected to always be at the beginning, when they are taken from the supplier.
+     * If the supplier returned the same stream instance, the reader would start at the wrong position when re-attempting a request.
+     *
+     * <p>When this supplier factory is used, {@link #getData()} will return a new instance on each call.
+     * It is the responsibility of the caller to close that stream.
+     *
+     * @param  name
+     *         The file name
+     * @param  supplier
+     *         The resource supplier, which returns a new {@link Source} on each call
+     *
+     * @throws IllegalArgumentException
+     *         If null is provided or the name is blank
+     *
+     * @return {@link FileUpload}
+     */
+    @Nonnull
+    public static FileUpload fromSourceSupplier(@Nonnull String name, @Nonnull Supplier<? extends Source> supplier)
+    {
+        Checks.notNull(supplier, "Supplier");
+        Checks.notBlank(name, "Name");
+        return new FileUpload(supplier, name);
+    }
+
     /**
      * Create a new {@link FileUpload} for an input stream.
      * <br>This is used to upload data to discord for various purposes.
@@ -320,7 +388,10 @@ public String getDescription()
     @Nonnull
     public InputStream getData()
     {
-        return resource;
+        if (resource != null)
+            return resource;
+        else
+            return Okio.buffer(resourceSupplier.get()).inputStream();
     }
 
     /**
@@ -343,7 +414,11 @@ public synchronized RequestBody getRequestBody(@Nonnull MediaType type)
         Checks.notNull(type, "Type");
         if (body != null) // This allows FileUpload to be used more than once!
             return body.withType(type);
-        return body = IOUtil.createRequestBody(type, resource);
+
+        if (resource == null)
+            return body = new DataSupplierBody(type, resourceSupplier);
+        else
+            return body = IOUtil.createRequestBody(type, resource);
     }
 
     @Override
@@ -381,7 +456,7 @@ public void forceClose() throws IOException
     @SuppressWarnings("deprecation")
     protected void finalize()
     {
-        if (body == null) // Only close if the resource was never used
+        if (body == null && resource != null) // Only close if the resource was never used
             IOUtil.silentClose(resource);
     }
 

src/main/java/net/dv8tion/jda/internal/utils/IOUtil.java

@@ -17,6 +17,7 @@
 package net.dv8tion.jda.internal.utils;
 
 import com.neovisionaries.ws.client.WebSocketFactory;
+import net.dv8tion.jda.internal.utils.requestbody.BufferedRequestBody;
 import okhttp3.ConnectionPool;
 import okhttp3.Dispatcher;
 import okhttp3.MediaType;

src/main/java/net/dv8tion/jda/internal/utils/BufferedRequestBody.java → src/main/java/net/dv8tion/jda/internal/utils/requestbody/BufferedRequestBody.java

@@ -14,29 +14,27 @@
  * limitations under the License.
  */
 
-package net.dv8tion.jda.internal.utils;
+package net.dv8tion.jda.internal.utils.requestbody;
 
+import net.dv8tion.jda.internal.utils.IOUtil;
 import okhttp3.MediaType;
-import okhttp3.RequestBody;
 import okio.BufferedSink;
 import okio.BufferedSource;
 import okio.Okio;
 import okio.Source;
 
 import javax.annotation.Nonnull;
-import javax.annotation.Nullable;
 import java.io.IOException;
 
-public class BufferedRequestBody extends RequestBody
+public class BufferedRequestBody extends TypedBody<BufferedRequestBody>
 {
     private final Source source;
-    private final MediaType type;
     private byte[] data;
 
     public BufferedRequestBody(Source source, MediaType type)
     {
+        super(type);
         this.source = source;
-        this.type = type;
     }
 
     @Nonnull
@@ -52,13 +50,6 @@ public BufferedRequestBody withType(@Nonnull MediaType type)
         }
     }
 
-    @Nullable
-    @Override
-    public MediaType contentType()
-    {
-        return type;
-    }
-
     @Override
     public void writeTo(@Nonnull BufferedSink sink) throws IOException
     {

src/main/java/net/dv8tion/jda/internal/utils/requestbody/DataSupplierBody.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2015 Austin Keener, Michael Ritter, Florian Spieß, and the JDA contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dv8tion.jda.internal.utils.requestbody;
+
+import okhttp3.MediaType;
+import okio.BufferedSink;
+import okio.Source;
+
+import javax.annotation.Nonnull;
+import java.io.IOException;
+import java.util.function.Supplier;
+
+public class DataSupplierBody extends TypedBody<DataSupplierBody>
+{
+    private final Supplier<? extends Source> streamSupply;
+
+    public DataSupplierBody(MediaType type, Supplier<? extends Source> streamSupply)
+    {
+        super(type);
+        this.streamSupply = streamSupply;
+    }
+
+    @Nonnull
+    @Override
+    public DataSupplierBody withType(@Nonnull MediaType newType)
+    {
+        if (this.type.equals(newType))
+            return this;
+        return new DataSupplierBody(newType, streamSupply);
+    }
+
+    @Override
+    public void writeTo(@Nonnull BufferedSink bufferedSink) throws IOException
+    {
+        synchronized (streamSupply)
+        {
+            try (Source stream = streamSupply.get())
+            {
+                bufferedSink.writeAll(stream);
+            }
+        }
+    }
+}

src/main/java/net/dv8tion/jda/internal/utils/requestbody/TypedBody.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2015 Austin Keener, Michael Ritter, Florian Spieß, and the JDA contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dv8tion.jda.internal.utils.requestbody;
+
+import okhttp3.MediaType;
+import okhttp3.RequestBody;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+public abstract class TypedBody<T extends TypedBody<T>> extends RequestBody
+{
+    protected final MediaType type;
+
+    protected TypedBody(MediaType type)
+    {
+        this.type = type;
+    }
+
+    @Nonnull
+    public abstract T withType(@Nonnull MediaType newType);
+
+    @Nullable
+    @Override
+    public MediaType contentType()
+    {
+        return type;
+    }
+}