sinmetal/FileInfo.java

## FileInfo.java
package org.sinmetal.appengine.sample.model.gcs;

import org.slim3.datastore.Attribute;
import org.slim3.datastore.Datastore;
import org.slim3.datastore.Model;

import com.google.appengine.api.datastore.Key;

@Model(schemaVersionName = "schemaVersion", schemaVersion = 1)
public class FileInfo {

    @Attribute(primaryKey = true)
	Key key;

	String gsBucketName;

	String fileName;

	String remarks;


	public static Key createKey(String bucketName, String fileName) {
		return Datastore.createKey(FileInfo.class, String.format("%s-_-%s", bucketName, fileName));
	}

	/**
	 * @return the key
	 * @category accessor
	 */
	public Key getKey() {
		return key;
	}

	/**
	 * @param key the key to set
	 * @category accessor
	 */
	public void setKey(Key key) {
		this.key = key;
	}

	/**
	 * @return the gsBucketName
	 * @category accessor
	 */
	public String getGsBucketName() {
		return gsBucketName;
	}

	/**
	 * @param gsBucketName the gsBucketName to set
	 * @category accessor
	 */
	public void setGsBucketName(String gsBucketName) {
		this.gsBucketName = gsBucketName;
	}

	/**
	 * @return the fileName
	 * @category accessor
	 */
	public String getFileName() {
		return fileName;
	}

	/**
	 * @param fileName the fileName to set
	 * @category accessor
	 */
	public void setFileName(String fileName) {
		this.fileName = fileName;
	}

	/**
	 * @return the remarks
	 * @category accessor
	 */
	public String getRemarks() {
		return remarks;
	}

	/**
	 * @param remarks the remarks to set
	 * @category accessor
	 */
	public void setRemarks(String remarks) {
		this.remarks = remarks;
	}

}

## FileService.java
package org.sinmetal.appengine.sample.service.gcs;

import java.io.IOException;
import java.io.OutputStream;
import java.nio.channels.Channels;

import org.sinmetal.appengine.sample.model.gcs.FileInfo;
import org.slim3.controller.upload.FileItem;
import org.slim3.datastore.Datastore;

import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.datastore.Transaction;
import com.google.appengine.tools.cloudstorage.GcsFileOptions;
import com.google.appengine.tools.cloudstorage.GcsFilename;
import com.google.appengine.tools.cloudstorage.GcsOutputChannel;
import com.google.appengine.tools.cloudstorage.GcsService;
import com.google.appengine.tools.cloudstorage.GcsServiceFactory;

public class FileService {

    public static Key entry(String bucketName, String remarks, FileItem fileItem)
			throws IOException {
		final GcsService gcsService = GcsServiceFactory.createGcsService();

		Transaction tx = null;
		try {
			tx = Datastore.beginTransaction();
			final GcsFilename gcsFilename = new GcsFilename(bucketName, fileItem.getFileName());
			GcsOutputChannel outputChannel =
					gcsService.createOrReplace(gcsFilename, GcsFileOptions.getDefaultInstance());
			try (OutputStream outputStream = Channels.newOutputStream(outputChannel)) {
				outputStream.write(fileItem.getData());
			}

			FileInfo fileInfo = new FileInfo();
			fileInfo.setKey(FileInfo.createKey(bucketName, fileItem.getFileName()));
			fileInfo.setGsBucketName(bucketName);
			fileInfo.setFileName(fileItem.getFileName());
			fileInfo.setRemarks(remarks);
			Key key = Datastore.put(fileInfo);
			tx.commit();
			return key;
		} finally {
			if (tx != null && tx.isActive()) {
				tx.rollback();
			}
		}

	}
}

## index.html
<!DOCTYPE html>
<html>
<head>
    <title>GoogleCloudStorageSample</title>
    <meta charset="utf-8">
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script>
        $(document).ready(function () {
            $("#create").on("click", function () {
                var $form = $("#entryForm");
                var formData = new FormData($form[0]);
                var promise = $.ajax({
                    type: "POST",
                    url: "/gcs/upload",
                    processData: false,
                    contentType: false,
                    data: formData
                });
                promise
                        .success(function () {
                            alert("作成しました");
                        })
                        .error(function () {
                            alert("作成に失敗しました");
                        });
                return false;
            });
        });
    </script>
</head>
<body>

<form id="entryForm">
    画像:<input name="file" type="file" enctype="multipart/form-data">
    <input name="remarks" type="text" placeholder="備考">
    <button id="create">作成する</button>
</form>

</body>
</html>

## UploadController.java
package org.sinmetal.appengine.sample.controller.gcs;

import org.sinmetal.appengine.sample.service.gcs.FileService;
import org.slim3.controller.Controller;
import org.slim3.controller.Navigation;
import org.slim3.controller.upload.FileItem;

/**
 * @author sinmetal
 */
public class UploadController extends Controller {

    @Override
	protected Navigation run() throws Exception {
		final String remarks = asString("remarks");
		final FileItem fileItem = requestScope("file");

		FileService.entry("your-bucket-name", remarks, fileItem);
		return null;
	}

}
	package org.sinmetal.appengine.sample.model.gcs;

	import org.slim3.datastore.Attribute;
	import org.slim3.datastore.Datastore;
	import org.slim3.datastore.Model;

	import com.google.appengine.api.datastore.Key;

	@Model(schemaVersionName = "schemaVersion", schemaVersion = 1)
	public class FileInfo {

	@Attribute(primaryKey = true)
	Key key;

	String gsBucketName;

	String fileName;

	String remarks;


	public static Key createKey(String bucketName, String fileName) {
	return Datastore.createKey(FileInfo.class, String.format("%s-_-%s", bucketName, fileName));
	}

	/**
	* @return the key
	* @category accessor
	*/
	public Key getKey() {
	return key;
	}

	/**
	* @param key the key to set
	* @category accessor
	*/
	public void setKey(Key key) {
	this.key = key;
	}

	/**
	* @return the gsBucketName
	* @category accessor
	*/
	public String getGsBucketName() {
	return gsBucketName;
	}

	/**
	* @param gsBucketName the gsBucketName to set
	* @category accessor
	*/
	public void setGsBucketName(String gsBucketName) {
	this.gsBucketName = gsBucketName;
	}

	/**
	* @return the fileName
	* @category accessor
	*/
	public String getFileName() {
	return fileName;
	}

	/**
	* @param fileName the fileName to set
	* @category accessor
	*/
	public void setFileName(String fileName) {
	this.fileName = fileName;
	}

	/**
	* @return the remarks
	* @category accessor
	*/
	public String getRemarks() {
	return remarks;
	}

	/**
	* @param remarks the remarks to set
	* @category accessor
	*/
	public void setRemarks(String remarks) {
	this.remarks = remarks;
	}

	}
	package org.sinmetal.appengine.sample.service.gcs;

	import java.io.IOException;
	import java.io.OutputStream;
	import java.nio.channels.Channels;

	import org.sinmetal.appengine.sample.model.gcs.FileInfo;
	import org.slim3.controller.upload.FileItem;
	import org.slim3.datastore.Datastore;

	import com.google.appengine.api.datastore.Key;
	import com.google.appengine.api.datastore.Transaction;
	import com.google.appengine.tools.cloudstorage.GcsFileOptions;
	import com.google.appengine.tools.cloudstorage.GcsFilename;
	import com.google.appengine.tools.cloudstorage.GcsOutputChannel;
	import com.google.appengine.tools.cloudstorage.GcsService;
	import com.google.appengine.tools.cloudstorage.GcsServiceFactory;

	public class FileService {

	public static Key entry(String bucketName, String remarks, FileItem fileItem)
	throws IOException {
	final GcsService gcsService = GcsServiceFactory.createGcsService();

	Transaction tx = null;
	try {
	tx = Datastore.beginTransaction();
	final GcsFilename gcsFilename = new GcsFilename(bucketName, fileItem.getFileName());
	GcsOutputChannel outputChannel =
	gcsService.createOrReplace(gcsFilename, GcsFileOptions.getDefaultInstance());
	try (OutputStream outputStream = Channels.newOutputStream(outputChannel)) {
	outputStream.write(fileItem.getData());
	}

	FileInfo fileInfo = new FileInfo();
	fileInfo.setKey(FileInfo.createKey(bucketName, fileItem.getFileName()));
	fileInfo.setGsBucketName(bucketName);
	fileInfo.setFileName(fileItem.getFileName());
	fileInfo.setRemarks(remarks);
	Key key = Datastore.put(fileInfo);
	tx.commit();
	return key;
	} finally {
	if (tx != null && tx.isActive()) {
	tx.rollback();
	}
	}

	}
	}
	<!DOCTYPE html>
	<html>
	<head>
	<title>GoogleCloudStorageSample</title>
	<meta charset="utf-8">
	<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
	<script>
	$(document).ready(function () {
	$("#create").on("click", function () {
	var $form = $("#entryForm");
	var formData = new FormData($form[0]);
	var promise = $.ajax({
	type: "POST",
	url: "/gcs/upload",
	processData: false,
	contentType: false,
	data: formData
	});
	promise
	.success(function () {
	alert("作成しました");
	})
	.error(function () {
	alert("作成に失敗しました");
	});
	return false;
	});
	});
	</script>
	</head>
	<body>

	<form id="entryForm">
	画像:<input name="file" type="file" enctype="multipart/form-data">
	<input name="remarks" type="text" placeholder="備考">
	<button id="create">作成する</button>
	</form>

	</body>
	</html>
	package org.sinmetal.appengine.sample.controller.gcs;

	import org.sinmetal.appengine.sample.service.gcs.FileService;
	import org.slim3.controller.Controller;
	import org.slim3.controller.Navigation;
	import org.slim3.controller.upload.FileItem;

	/**
	* @author sinmetal
	*/
	public class UploadController extends Controller {

	@Override
	protected Navigation run() throws Exception {
	final String remarks = asString("remarks");
	final FileItem fileItem = requestScope("file");

	FileService.entry("your-bucket-name", remarks, fileItem);
	return null;
	}

	}