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Posted to notifications@accumulo.apache.org by GitBox <gi...@apache.org> on 2021/04/22 18:49:11 UTC
[GitHub] [accumulo-website] ctubbsii commented on a change in pull request #274: Add JShell Accumulo Feature Blog
ctubbsii commented on a change in pull request #274:
URL: https://github.com/apache/accumulo-website/pull/274#discussion_r618629518
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File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
Review comment:
I'm not a huge fan of either the Author info (for the same reason Apache projects don't use the `@author` tag in source code, because it's a community-maintained group effort, that all of us are responsible for). However, I recognize that blog posts are somewhat different than source code, since they are typically authored at a point in time, rather than continuously maintained. So, I think it's fine if you want to leave that. Just know that it's optional.
I'm also not a fan of the "Reviewers" tag, either, but for additional reasons. First, it is intended to reflect reviewers of the blog post itself, not the work the blog post is describing. So, right now, it should be blank anyway. Second, I don't think it adds any value. The intent of having this seems to be to try to give credit for contributors who may have made significant contributions as editors in the review process. However, for me personally, it feels like I'm being singled out as responsible in some way for its content, rather than the entire project being responsible for its content. I'm also uncomfortable trying to weigh merit against other individuals like this (it raises the question of how much contributing makes you a reviewer, or how much contributing would make you a co-author).
So, feel free to retain your Author tag if you want, but please remove the Reviewers lines for now, and if you add it back later in response to other reviewers, please leave my name off of it, since I'm not comfortable being called out on the blog posts by name. I really wish we hadn't started this precedent in previous blog posts.
Thanks!
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File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
+Java tool that assess user's inputed declarations, statements, and expressions and outputs
Review comment:
```suggestion
Java tool that interprets user's input as Java and outputs
```
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File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
Review comment:
```suggestion
First introduced in Java 9, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
```
##########
File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
+Java tool that assess user's inputed declarations, statements, and expressions and outputs
+the results. This tool provides a convenient way to test out and execute quick tasks with Accumulo
+in the terminal.
+
+## Major Features
+* During Accumulo build, produces a default JShell script called `jshell-init.jsh`
+containing up-to-date [Accumulo Java APIs][public APIs] and [AccumuloClient][client]
+build implementation
Review comment:
Instead of mentioning how it is built, which isn't quite relevant to end users, it should instead mention that a default `conf/jshell-init.jsh` file is provided in our binary distribution tarball, and includes some initial imports for interacting with Accumulo's API.
It might be worth mentioning that JShell could be run manually using the user's installed `jshell` command from their installation of Java, but that by running it with `bin/accumulo jshell`, it will automatically pick up the `CLASSPATH` and other environment from the user's `conf/accumulo-env.sh` and automatically initialize with the provided `conf/jshell-init.jsh` file, which can also be customized by users.
Since all of this is something a user could already do themselves, I think the main focus of this blog post should be on the convenience that it offers to users, so that they don't have to do it all manually.
##########
File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
+Java tool that assess user's inputed declarations, statements, and expressions and outputs
+the results. This tool provides a convenient way to test out and execute quick tasks with Accumulo
+in the terminal.
+
+## Major Features
+* During Accumulo build, produces a default JShell script called `jshell-init.jsh`
+containing up-to-date [Accumulo Java APIs][public APIs] and [AccumuloClient][client]
+build implementation
+
+* Startup JShell with default or custom JShell script
+
+* Both JShell start up options automatically import all relevant Java APIs
+
+## Booting Up JShell Accumulo
+After installing and configuring the [latest Accumulo update][accumulo-repo]
Review comment:
Since this is a 2.1 feature, we could point to the downloads page. If we want to publish this blog post before 2.1 is released, then some of the wording could be tailored to refer to the "upcoming 2.1 release" for this feature, with perhaps a minor mention that they could build pre-release snapshot versions to try it out from the git repository if 2.1 isn't released by the time they read this.
##########
File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
+Java tool that assess user's inputed declarations, statements, and expressions and outputs
+the results. This tool provides a convenient way to test out and execute quick tasks with Accumulo
+in the terminal.
+
+## Major Features
+* During Accumulo build, produces a default JShell script called `jshell-init.jsh`
+containing up-to-date [Accumulo Java APIs][public APIs] and [AccumuloClient][client]
+build implementation
+
+* Startup JShell with default or custom JShell script
+
+* Both JShell start up options automatically import all relevant Java APIs
+
+## Booting Up JShell Accumulo
+After installing and configuring the [latest Accumulo update][accumulo-repo]
+follow the steps below to startup JShell:
+
+1) Open up a terminal and navigate to Accumulo's home directory
Review comment:
Since "home directory" has a special meaning in Linux environments, it'd be better to refer to the Accumulo installation directory, if using the binary distribution tarball we provide. If they're using a distribution from a commercial vendor or other distributor, their experience may be different.
##########
File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
+Java tool that assess user's inputed declarations, statements, and expressions and outputs
+the results. This tool provides a convenient way to test out and execute quick tasks with Accumulo
+in the terminal.
+
+## Major Features
+* During Accumulo build, produces a default JShell script called `jshell-init.jsh`
+containing up-to-date [Accumulo Java APIs][public APIs] and [AccumuloClient][client]
+build implementation
+
+* Startup JShell with default or custom JShell script
+
+* Both JShell start up options automatically import all relevant Java APIs
Review comment:
By default they import classes to interact with the Accumulo API... but might not be all relevant Java APIs for the user's intended task. Also, this is only by default. The file is customizable by the user in their conf/ directory.
##########
File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
+Java tool that assess user's inputed declarations, statements, and expressions and outputs
+the results. This tool provides a convenient way to test out and execute quick tasks with Accumulo
+in the terminal.
+
+## Major Features
+* During Accumulo build, produces a default JShell script called `jshell-init.jsh`
+containing up-to-date [Accumulo Java APIs][public APIs] and [AccumuloClient][client]
+build implementation
+
+* Startup JShell with default or custom JShell script
+
+* Both JShell start up options automatically import all relevant Java APIs
+
+## Booting Up JShell Accumulo
+After installing and configuring the [latest Accumulo update][accumulo-repo]
+follow the steps below to startup JShell:
+
+1) Open up a terminal and navigate to Accumulo's home directory
+
+2) To startup JShell with **default script** use this command:
+
+```bash
+$ bin/accumulo jshell
+```
+3) To startup JShell with **custom script** use this command:
+
+```bash
+$ bin/accumulo jshell --startup (file/path/to/custom_script.jsh)
+```
+## JShell Accumulo Default Script
+The auto-generated `jshell-init.jsh` is located in Accumulo's `conf/` directory.
+Inside `jshell-init.jsh` contains [Accumulo Java APIs][public APIs] formatted as import statements
+and [AccumuloClient][client] build implementation. On startup the script automatically loads in the
+APIs and attempts to construct a client. Should additional APIs and/or code implementations be
+needed, simply append them to `jshell-init.jsh`. Alternatively you can create a separate JShell
+script and specify the custom script's file path on startup.
+
+The build implementation finds and uses `accumulo-client.properties` in Accumulo's
+classpath to auto-generate an [AccumuloClient][client] called **client**.
+If `accumulo-client.properties` is found, a similar result will be produced below:
+
+```
+Preparing JShell for Apache Accumulo
+
+Building Accumulo client using 'jar:file:/home/accumulo/lib/accumulo-client.jar!/accumulo-client.properties'
+
+Use 'client' to interact with Accumulo
+
+| Welcome to JShell -- Version 11.0.10
+| For an introduction type: /help intro
+
+jshell>
+```
+If `accumulo-client.properties` is not found, an [AccumuloClient][client] will not
+auto-generate and will produce the following result below:
+
+```
+Preparing JShell for Apache Accumulo
+
+'accumulo-client.properties' was not found on the classpath
+
+| Welcome to JShell -- Version 11.0.10
+| For an introduction type: /help intro
+
+jshell>
+```
+
+## JShell Accumulo Example
+1) Booting up JShell using default script
+
+```
+Preparing JShell for Apache Accumulo
+
+Building Accumulo client using 'file:/home/accumulo/conf/accumulo-client.properties'
+
+Use 'client' to interact with Accumulo
+
+| Welcome to JShell -- Version 11.0.10
+| For an introduction type: /help intro
+
+jshell>
+```
+
+2) Providing JShell with an Accumulo task
+
+```Java
+ // Create a table called "GothamPD".
+ client.tableOperations().create("GothamPD");
+
+ // Create a Mutation object to hold all changes to a row in a table.
+ // Each row has a unique row ID.
+ Mutation mutation = new Mutation("id0001");
+
+ // Create key/value pairs for Batman. Put them in the "hero" family.
+ mutation.put("hero", "alias", "Batman");
+ mutation.put("hero", "name", "Bruce Wayne");
+ mutation.put("hero", "wearsCape?", "true");
+
+ // Create a BatchWriter to the GothamPD table and add your mutation to it.
+ // Try w/ resources will close for us.
+ try (BatchWriter writer = client.createBatchWriter("GothamPD")) {
+ writer.addMutation(mutation);
+ }
+
+ // Read and print all rows of the "GothamPD" table.
+ // Try w/ resources will close for us.
+ try (org.apache.accumulo.core.client.Scanner scan =
+ client.createScanner("GothamPD", Authorizations.EMPTY)) {
+ System.out.println("Gotham Police Department Persons of Interest:");
+
+ // A Scanner is an extension of java.lang.Iterable so behaves just like one.
+ for (Map.Entry<Key,Value> entry : scan) {
+ System.out.printf("Key : %-50s Value : %s\n", entry.getKey(), entry.getValue());
+ }
Review comment:
As of 2.1, we can use scanner.forEach, which makes this slightly nicer example code:
```suggestion
scan.forEach((k, v) -> System.out.printf("Key : %-50s Value : %s\n", k, v));
```
##########
File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
+Java tool that assess user's inputed declarations, statements, and expressions and outputs
+the results. This tool provides a convenient way to test out and execute quick tasks with Accumulo
+in the terminal.
+
+## Major Features
+* During Accumulo build, produces a default JShell script called `jshell-init.jsh`
+containing up-to-date [Accumulo Java APIs][public APIs] and [AccumuloClient][client]
+build implementation
+
+* Startup JShell with default or custom JShell script
+
+* Both JShell start up options automatically import all relevant Java APIs
+
+## Booting Up JShell Accumulo
+After installing and configuring the [latest Accumulo update][accumulo-repo]
+follow the steps below to startup JShell:
+
+1) Open up a terminal and navigate to Accumulo's home directory
+
+2) To startup JShell with **default script** use this command:
+
+```bash
+$ bin/accumulo jshell
+```
+3) To startup JShell with **custom script** use this command:
+
+```bash
+$ bin/accumulo jshell --startup (file/path/to/custom_script.jsh)
+```
+## JShell Accumulo Default Script
+The auto-generated `jshell-init.jsh` is located in Accumulo's `conf/` directory.
+Inside `jshell-init.jsh` contains [Accumulo Java APIs][public APIs] formatted as import statements
+and [AccumuloClient][client] build implementation. On startup the script automatically loads in the
+APIs and attempts to construct a client. Should additional APIs and/or code implementations be
+needed, simply append them to `jshell-init.jsh`. Alternatively you can create a separate JShell
+script and specify the custom script's file path on startup.
Review comment:
Might be worth mentioning that you can append any options that you might append to the `jshell` command-line if you were running that directly.
##########
File path: _posts/blog/2021-04-21-jshell-accumulo-feature.md
##########
@@ -0,0 +1,141 @@
+---
+Title: JShell Accumulo Feature
+Author: R. Dane Magbuhos
+Reviewers: Christopher Tubbs, Keith Turner
+---
+
+## Overview
+First introduced in Java 9+, [JShell][JShell Doc] is an interactive Read-Evaluate-Print-Loop (REPL)
+Java tool that assess user's inputed declarations, statements, and expressions and outputs
+the results. This tool provides a convenient way to test out and execute quick tasks with Accumulo
+in the terminal.
+
+## Major Features
+* During Accumulo build, produces a default JShell script called `jshell-init.jsh`
+containing up-to-date [Accumulo Java APIs][public APIs] and [AccumuloClient][client]
+build implementation
+
+* Startup JShell with default or custom JShell script
+
+* Both JShell start up options automatically import all relevant Java APIs
+
+## Booting Up JShell Accumulo
+After installing and configuring the [latest Accumulo update][accumulo-repo]
+follow the steps below to startup JShell:
+
+1) Open up a terminal and navigate to Accumulo's home directory
+
+2) To startup JShell with **default script** use this command:
+
+```bash
+$ bin/accumulo jshell
+```
+3) To startup JShell with **custom script** use this command:
+
+```bash
+$ bin/accumulo jshell --startup (file/path/to/custom_script.jsh)
+```
+## JShell Accumulo Default Script
+The auto-generated `jshell-init.jsh` is located in Accumulo's `conf/` directory.
+Inside `jshell-init.jsh` contains [Accumulo Java APIs][public APIs] formatted as import statements
+and [AccumuloClient][client] build implementation. On startup the script automatically loads in the
+APIs and attempts to construct a client. Should additional APIs and/or code implementations be
+needed, simply append them to `jshell-init.jsh`. Alternatively you can create a separate JShell
+script and specify the custom script's file path on startup.
+
+The build implementation finds and uses `accumulo-client.properties` in Accumulo's
+classpath to auto-generate an [AccumuloClient][client] called **client**.
+If `accumulo-client.properties` is found, a similar result will be produced below:
+
+```
+Preparing JShell for Apache Accumulo
+
+Building Accumulo client using 'jar:file:/home/accumulo/lib/accumulo-client.jar!/accumulo-client.properties'
+
+Use 'client' to interact with Accumulo
+
+| Welcome to JShell -- Version 11.0.10
+| For an introduction type: /help intro
+
+jshell>
+```
+If `accumulo-client.properties` is not found, an [AccumuloClient][client] will not
+auto-generate and will produce the following result below:
+
+```
+Preparing JShell for Apache Accumulo
+
+'accumulo-client.properties' was not found on the classpath
+
+| Welcome to JShell -- Version 11.0.10
+| For an introduction type: /help intro
+
+jshell>
+```
+
+## JShell Accumulo Example
+1) Booting up JShell using default script
+
+```
+Preparing JShell for Apache Accumulo
+
+Building Accumulo client using 'file:/home/accumulo/conf/accumulo-client.properties'
+
+Use 'client' to interact with Accumulo
+
+| Welcome to JShell -- Version 11.0.10
+| For an introduction type: /help intro
+
+jshell>
+```
+
+2) Providing JShell with an Accumulo task
+
+```Java
+ // Create a table called "GothamPD".
+ client.tableOperations().create("GothamPD");
+
+ // Create a Mutation object to hold all changes to a row in a table.
+ // Each row has a unique row ID.
+ Mutation mutation = new Mutation("id0001");
+
+ // Create key/value pairs for Batman. Put them in the "hero" family.
+ mutation.put("hero", "alias", "Batman");
+ mutation.put("hero", "name", "Bruce Wayne");
+ mutation.put("hero", "wearsCape?", "true");
+
+ // Create a BatchWriter to the GothamPD table and add your mutation to it.
+ // Try w/ resources will close for us.
+ try (BatchWriter writer = client.createBatchWriter("GothamPD")) {
+ writer.addMutation(mutation);
+ }
+
+ // Read and print all rows of the "GothamPD" table.
+ // Try w/ resources will close for us.
+ try (org.apache.accumulo.core.client.Scanner scan =
+ client.createScanner("GothamPD", Authorizations.EMPTY)) {
Review comment:
Might be worth a mention that the fully-qualified class name for Scanner needs to be used because of a conflict with Java's built-in `java.util.Scanner`, but that if they want to use a shortname, they can assign it to the `ScannerBase` type instead.
```suggestion
// Read and print all rows of the "GothamPD" table.
// Try w/ resources will close for us.
try (ScannerBase scan = client.createScanner("GothamPD", Authorizations.EMPTY)) {
```
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