BAEL-1544 - Intro to Google Cloud Storage with Java (#3693)

* Initial additions

* Initial additions

* BAEL-1544 - Intro to Google Cloud Storage With Java

* BAEL-1544 - Intro to Google Cloud Storage With Java

google-cloud/README.md

@@ -0,0 +1,16 @@
+## Google Cloud Tutorial Project
+
+### Relevant Article:
+- [Intro to Google Cloud Storage With Java](http://www.baeldung.com/intro-to-google-cloud-storage-with-java/)
+
+### Overview
+This Maven project contains the Java code for the article linked above.
+
+### Package Organization
+Java classes for the intro tutorial are in the org.baeldung.google.cloud package. Please note that Google Cloud requires
+a user account and credentials, as explained in the tutorial.
+
+
+### Running the tests
+
+```

google-cloud/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>google-cloud</artifactId>
+    <version>0.1-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>google-cloud</name>
+    <description>Google Cloud Tutorials</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.google.cloud</groupId>
+            <artifactId>google-cloud-storage</artifactId>
+            <version>1.16.0</version>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <!-- Check for the most recent available version: https://projectlombok.org/changelog.html -->
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <lombok.version>1.16.18</lombok.version>
+        <java.version>1.8</java.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+</project>

google-cloud/src/main/java/com/baeldung/google/cloud/storage/GoogleCloudStorage.java

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+package com.baeldung.google.cloud.storage;
+
+import com.google.api.gax.paging.Page;
+import com.google.auth.Credentials;
+import com.google.auth.oauth2.GoogleCredentials;
+import com.google.cloud.storage.*;
+import lombok.extern.slf4j.Slf4j;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.WritableByteChannel;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+/**
+ * Simple class for creating, reading and modifying text blobs on Google Cloud
+ */
+@Slf4j
+public class GoogleCloudStorage {
+
+    private Storage storage;
+    private Bucket bucket;
+
+    public static void main(String[] args) throws Exception {
+
+        // Use this variation to read the Google authorization JSON from the resources directory with a path
+        // and a project name.
+        GoogleCloudStorage googleCloudStorage =
+            new GoogleCloudStorage("google-cloud/src/main/resources/google_auth.json", "baeldung-cloud-tutorial");
+
+        // Bucket require globally unique names, so you'll probably need to change this
+        Bucket bucket = googleCloudStorage.getBucket("baeldung-1-bucket");
+
+        // Save a simple string
+        BlobId blobId = googleCloudStorage.saveString("my-first-blob", "Hi there!", bucket);
+
+        // Get it by blob id this time
+        String value = googleCloudStorage.getString(blobId);
+
+        log.info("Read data: {}", value);
+
+        googleCloudStorage.updateString(blobId, "Bye now!");
+
+        // Get the string by blob name
+        value = googleCloudStorage.getString("my-first-blob");
+
+        log.info("Read modified data: {}", value);
+
+
+    }
+
+
+    // Use path and project name
+    private GoogleCloudStorage(String pathToConfig, String projectId) throws IOException {
+        Credentials credentials = GoogleCredentials.fromStream(new FileInputStream(pathToConfig));
+        storage = StorageOptions.newBuilder().setCredentials(credentials).setProjectId(projectId).build().getService();
+    }
+
+    // Check for bucket existence and create if needed.
+    private Bucket getBucket(String bucketName) {
+        bucket = storage.get(bucketName);
+        if (bucket == null) {
+            System.out.println("Creating new bucket.");
+            bucket = storage.create(BucketInfo.of(bucketName));
+        }
+        return bucket;
+    }
+
+    // Save a string to a blob
+    private BlobId saveString(String blobName, String value, Bucket bucket) {
+        byte[] bytes = value.getBytes(UTF_8);
+        Blob blob = bucket.create(blobName, bytes);
+        return blob.getBlobId();
+    }
+
+
+    // get a blob by id
+    private String getString(BlobId blobId) {
+        Blob blob = storage.get(blobId);
+        return new String(blob.getContent());
+    }
+
+
+    // get a blob by name
+    private String getString(String name) {
+        Page<Blob> blobs = bucket.list();
+        for (Blob blob: blobs.getValues()) {
+            if (name.equals(blob.getName())) {
+                return new String(blob.getContent());
+            }
+        }
+        return "Blob not found";
+    }
+
+    // Update a blob
+    private void updateString(BlobId blobId, String newString) throws IOException {
+        Blob blob = storage.get(blobId);
+        if (blob != null) {
+            WritableByteChannel channel = blob.writer();
+            channel.write(ByteBuffer.wrap(newString.getBytes(UTF_8)));
+            channel.close();
+        }
+    }
+}

pom.xml

@@ -67,6 +67,7 @@
 
         <module>geotools</module>
         <module>testing-modules/groovy-spock</module>
+        <module>google-cloud</module>
         <module>gson</module>
         <module>guava</module>
         <module>guava-modules/guava-18</module>