Improve nio and contrib READMEs (googleapis#1077)

Author: jean-philippe-martin

gcloud-java-contrib/README.md

@@ -17,6 +17,9 @@ Contents
 
 Quickstart
 ----------
+
+### gcloud-java-nio
+
 If you are using Maven, add this to your pom.xml file
 ```xml
 <dependency>
@@ -34,6 +37,10 @@ If you are using SBT, add this to your dependencies
 libraryDependencies += "com.google.cloud" % "gcloud-java-contrib" % "0.2.4"
 ```
 
+### gcloud-java-nio-examples
+
+See its [README](./gcloud-java-nio-examples/README.md) for instructions on how to run it.
+
 Java Versions
 -------------
 

gcloud-java-contrib/gcloud-java-nio-examples/README.md

@@ -39,3 +39,5 @@ facility, the [standard way](http://docs.oracle.com/javase/7/docs/technotes/guid
 If you have access to a project's source code you can also simply add gcloud-java-nio as
 a dependency and let Maven pull in the required dependencies (this is what the nio unit tests do).
 This approach is preferable as the fat jar approach may waste memory on multiple copies of dependencies.
+
+[developers-console]:https://console.developers.google.com/

gcloud-java-contrib/gcloud-java-nio/README.md

@@ -0,0 +1,210 @@
+NIO Filesystem Provider for Google Cloud Storage (Alpha)
+========================================================
+
+Implementation of Java 7 `java.nio.file.FileSystem` for
+[Google Cloud Storage](https://cloud.google.com/storage/).
+
+This library allows you to use the standardized Java file system API
+for interacting with Google Cloud Storage.
+
+[![Build Status](https://travis-ci.org/GoogleCloudPlatform/gcloud-java.svg?branch=master)](https://travis-ci.org/GoogleCloudPlatform/gcloud-java)
+[![Coverage Status](https://coveralls.io/repos/GoogleCloudPlatform/gcloud-java/badge.svg?branch=master)](https://coveralls.io/r/GoogleCloudPlatform/gcloud-java?branch=master)
+[![Maven](https://img.shields.io/maven-central/v/com.google.cloud/gcloud-java-nio.svg)]( https://img.shields.io/maven-central/v/com.google.cloud/gcloud-java-nio.svg)
+[![Codacy Badge](https://api.codacy.com/project/badge/grade/9da006ad7c3a4fe1abd142e77c003917)](https://www.codacy.com/app/mziccard/gcloud-java)
+[![Dependency Status](https://www.versioneye.com/user/projects/56bd8ee72a29ed002d2b0969/badge.svg?style=flat)](https://www.versioneye.com/user/projects/56bd8ee72a29ed002d2b0969)
+
+-  [Homepage](https://googlecloudplatform.github.io/gcloud-java/)
+-  [API Documentation](http://googlecloudplatform.github.io/gcloud-java/apidocs/index.html?com/google/cloud/storage/package-summary.html)
+
+> Note: This client is a work-in-progress, and may occasionally
+> make backwards-incompatible changes.
+
+Quickstart
+----------
+If you are using Maven, add this to your pom.xml file
+```xml
+<dependency>
+  <groupId>com.google.cloud</groupId>
+  <artifactId>gcloud-java-nio</artifactId>
+  <version>0.2.3</version>
+</dependency>
+```
+If you are using Gradle, add this to your dependencies
+```Groovy
+compile 'com.google.cloud:gcloud-java-nio:0.2.3'
+```
+If you are using SBT, add this to your dependencies
+```Scala
+libraryDependencies += "com.google.cloud" % "gcloud-java-nio" % "0.2.3"
+```
+
+Example Applications
+-------------------
+
+* [`Stat`](../../gcloud-java-examples/src/main/java/com/google/cloud/examples/nio/Stat.java)
+shows how to get started with NIO.
+
+* [`ParallelCountBytes`](../../gcloud-java-examples/src/main/java/com/google/cloud/examples/nio/ParallelCountBytes.java)
+efficiently downloads a file from Google Cloud Storage.
+
+* [`ListFileSystems`](../gcloud-java-nio-examples/README.md) illustrates how
+NIO can add Google Cloud Storage support to some legacy programs, without
+having to modify them.
+
+
+Authentication
+--------------
+
+See the [Authentication](https://github.com/GoogleCloudPlatform/gcloud-java#authentication)
+section in the base directory's README.
+
+About Google Cloud Storage
+--------------------------
+
+[Google Cloud Storage][cloud-storage] is a durable and highly available
+object storage service. Google Cloud Storage is almost infinitely scalable
+and guarantees consistency: when a write succeeds, the latest copy of the
+object will be returned to any GET, globally.
+
+See the [Google Cloud Storage docs][cloud-storage-activation] for more details
+on how to activate Cloud Storage for your project.
+
+About Java NIO Providers
+------------------------
+
+Java NIO Providers is an extension mechanism that is part of Java and allows
+third parties to extend Java's [normal File API][java-file-api] to support
+additional filesystems.
+
+Getting Started
+---------------
+#### Prerequisites
+
+For this tutorial, you will need a [Google Developers
+Console](https://console.developers.google.com/) project with "Google Cloud
+Storage" and "Google Cloud Storage JSON API" enabled via the console's API
+Manager. You will need to [enable
+billing](https://support.google.com/cloud/answer/6158867?hl=en) to use Google
+Cloud Storage. [Follow these
+instructions](https://cloud.google.com/docs/authentication#preparation) to get
+your project set up. You will also need to set up the local development
+environment by [installing the Google Cloud SDK](https://cloud.google.com/sdk/)
+and running the following commands in command line: `gcloud auth login` and
+`gcloud config set project [YOUR PROJECT ID]`.
+
+#### Installation and setup
+You'll need to obtain the `gcloud-java-nio` library.
+
+There are two ways to use this library.
+
+The recommended way is to follow the [Quickstart](#quickstart) section to add
+`gcloud-java-nio` as a dependency in your code.
+
+The second way is more complicated, but it allows you to add Google Cloud
+Storage support to some legacy Java programs. This approach is described in the
+[gcloud-java-nio-examples README](../gcloud-java-nio-examples/README.md).
+
+#### Accessing files
+
+The simplest way to get started is with `Paths` and `Files`:
+
+    Path path = Paths.get(URI.create("gs://bucket/lolcat.csv"));
+    List<String> lines = Files.readAllLines(path, StandardCharsets.UTF_8);
+
+If you know the paths will point to Google Cloud Storage, you can also use the
+direct formulation:
+
+    try (CloudStorageFileSystem fs = CloudStorageFileSystem.forBucket("bucket") {
+      Path path = fs.getPath("lolcat.csv");
+      List<String> lines = Files.readAllLines(path, StandardCharsets.UTF_8);
+    }
+
+Once you have a `Path` you can use it as you would a normal file. For example
+you can use `InputStream` and `OutputStream` for streaming:
+
+    try (InputStream input = Files.openInputStream(path)) {
+      // ...
+    }
+
+You can also set various attributes using CloudStorageOptions static helpers:
+
+    Files.write(csvPath, csvLines, StandardCharsets.UTF_8,
+        withMimeType(MediaType.CSV_UTF8),
+        withoutCaching());
+
+Limitations
+-----------
+
+This library is usable, but not yet complete. The following features are not
+yet implemented:
+ * Listing all the buckets
+ * Resuming upload or download
+ * Generations
+ * File attributes
+ * (more)
+
+Some features are not on the roadmap: this library would be a poor choice to
+mirror a local filesystem onto the cloud because Google Cloud Storage has a
+different set of features from your local disk. This library, by design,
+does not mask those differences. Rather, it aims to expose the common
+subset via a familiar interface.
+
+**NOTE:** Cloud Storage uses a flat namespace and therefore doesn't support real
+directories. So this library supports what's known as "pseudo-directories". Any
+path that includes a trailing slash, will be considered a directory. It will
+always be assumed to exist, without performing any I/O. This allows you to do
+path manipulation in the same manner as you would with the normal UNIX file
+system implementation. You can disable this feature with
+`CloudStorageConfiguration.usePseudoDirectories()`.
+
+#### Complete source code
+
+There are examples in [gcloud-java-examples](../gcloud-java-examples/src/main/java/com/google/cloud/examples/nio/)
+for your perusal.
+
+Java Versions
+-------------
+
+Java 7 or above is required for using this client.
+
+Versioning
+----------
+
+This library follows [Semantic Versioning](http://semver.org/).
+
+It is currently in major version zero (``0.y.z``), which means that anything
+may change at any time and the public API should not be considered
+stable.
+
+Contributing
+------------
+
+Contributions to this library are always welcome and highly encouraged.
+
+See `gcloud-java`'s [CONTRIBUTING] documentation and the `gcloud-*`
+[shared documentation](https://github.com/GoogleCloudPlatform/gcloud-common/blob/master/contributing/readme.md#how-to-contribute-to-gcloud)
+for more information on how to get started.
+
+Please note that this project is released with a Contributor Code of Conduct.
+By participating in this project you agree to abide by its terms. See
+[Code of Conduct][code-of-conduct] for more information.
+
+License
+-------
+
+Apache 2.0 - See [LICENSE] for more information.
+
+
+[CONTRIBUTING]:https://github.com/GoogleCloudPlatform/gcloud-java/blob/master/CONTRIBUTING.md
+[code-of-conduct]:https://github.com/GoogleCloudPlatform/gcloud-java/blob/master/CODE_OF_CONDUCT.md#contributor-code-of-conduct
+[LICENSE]: https://github.com/GoogleCloudPlatform/gcloud-java/blob/master/LICENSE
+[TESTING]: https://github.com/GoogleCloudPlatform/gcloud-java/blob/master/TESTING.md#testing-code-that-uses-storage
+[cloud-platform]: https://cloud.google.com/
+
+[cloud-storage]: https://cloud.google.com/storage/
+[cloud-storage-docs]: https://cloud.google.com/storage/docs/overview
+[cloud-storage-create-bucket]: https://cloud.google.com/storage/docs/cloud-console#_creatingbuckets
+[storage-api]: http://googlecloudplatform.github.io/gcloud-java/apidocs/index.html?com/google/cloud/storage/package-summary.html
+[cloud-storage-activation]:https://cloud.google.com/storage/docs/signup?hl=en
+
+[java-file-api]: https://docs.oracle.com/javase/7/docs/api/java/nio/file/Files.html