CC-1441: Add Java Support for Grep

compiled_starters/java/.codecrafters/compile.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+#
+# This script is used to compile your program on CodeCrafters
+#
+# This runs before .codecrafters/run.sh
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit on failure
+
+mvn -B package -Ddir=/tmp/codecrafters-build-grep-java

compiled_starters/java/.codecrafters/run.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+#
+# This script is used to run your program on CodeCrafters
+#
+# This runs after .codecrafters/compile.sh
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit on failure
+
+exec java -jar /tmp/codecrafters-build-grep-java/codecrafters-grep.jar "$@"

compiled_starters/java/.gitattributes

@@ -0,0 +1 @@
+* text=auto

compiled_starters/java/.gitignore

@@ -0,0 +1,3 @@
+*.jar
+target/
+.idea/

compiled_starters/java/README.md

@@ -0,0 +1,39 @@
+![progress-banner](https://codecrafters.io/landing/images/default_progress_banners/grep.png)
+
+This is a starting point for Java solutions to the
+["Build Your Own grep" Challenge](https://app.codecrafters.io/courses/grep/overview).
+
+[Regular expressions](https://en.wikipedia.org/wiki/Regular_expression)
+(Regexes, for short) are patterns used to match character combinations in
+strings. [`grep`](https://en.wikipedia.org/wiki/Grep) is a CLI tool for
+searching using Regexes.
+
+In this challenge you'll build your own implementation of `grep`. Along the way
+we'll learn about Regex syntax, how parsers/lexers work, and how regular
+expressions are evaluated.
+
+**Note**: If you're viewing this repo on GitHub, head over to
+[codecrafters.io](https://codecrafters.io) to try the challenge.
+
+# Passing the first stage
+
+The entry point for your `grep` implementation is in `src/main/java/Main.java`.
+Study and uncomment the relevant code, and push your changes to pass the first
+stage:
+
+```sh
+git commit -am "pass 1st stage" # any msg
+git push origin master
+```
+
+Time to move on to the next stage!
+
+# Stage 2 & beyond
+
+Note: This section is for stages 2 and beyond.
+
+1. Ensure you have `mvn` installed locally
+1. Run `./your_program.sh` to run your program, which is implemented in
+   `src/main/java/Main.java`.
+1. Commit your changes and run `git push origin master` to submit your solution
+   to CodeCrafters. Test output will be streamed to your terminal.

compiled_starters/java/codecrafters.yml

@@ -0,0 +1,11 @@
+# Set this to true if you want debug logs.
+#
+# These can be VERY verbose, so we suggest turning them off
+# unless you really need them.
+debug: false
+
+# Use this to change the Java version used to run your code
+# on Codecrafters.
+#
+# Available versions: java-23
+language_pack: java-23

compiled_starters/java/pom.xml

@@ -0,0 +1,52 @@
+<?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>
+
+    <groupId>io.codecrafters</groupId>
+    <artifactId>codecrafters-grep</artifactId>
+    <version>1.0</version>
+
+    <properties>
+        <maven.compiler.source>23</maven.compiler.source>
+        <maven.compiler.target>23</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <java.version>23</java.version>
+    </properties>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <configuration>
+                    <finalName>codecrafters-grep</finalName> <!-- Please do not change this final artifact name-->
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                    <appendAssemblyId>false</appendAssemblyId>
+                    <archive>
+                        <manifest>
+                            <addClasspath>true</addClasspath>
+                            <!-- This is the main class of your program which will be executed-->
+                            <mainClass>Main</mainClass>
+                        </manifest>
+                    </archive>
+                    <outputDirectory>${dir}</outputDirectory>
+                </configuration>
+
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

compiled_starters/java/src/main/java/Main.java

@@ -0,0 +1,34 @@
+import java.io.IOException;
+import java.util.Scanner;
+
+public class Main {
+  public static void main(String[] args){
+    if (args.length != 2 || !args[0].equals("-E")) {
+      System.out.println("Usage: ./your_program.sh -E <pattern>");
+      System.exit(1);
+    }
+
+    String pattern = args[1];  
+    Scanner scanner = new Scanner(System.in);
+    String inputLine = scanner.nextLine();
+
+    // You can use print statements as follows for debugging, they'll be visible when running tests.
+    System.err.println("Logs from your program will appear here!");
+
+    // Uncomment this block to pass the first stage
+    // 
+    // if (matchPattern(inputLine, pattern)) {
+    //     System.exit(0);
+    // } else {
+    //     System.exit(1);
+    // }
+  }
+
+  public static boolean matchPattern(String inputLine, String pattern) {
+    if (pattern.length() == 1) {
+      return inputLine.contains(pattern);
+    } else {
+      throw new RuntimeException("Unhandled pattern: " + pattern);
+    }
+  }
+}

compiled_starters/java/your_program.sh

@@ -0,0 +1,24 @@
+#!/bin/sh
+#
+# Use this script to run your program LOCALLY.
+#
+# Note: Changing this script WILL NOT affect how CodeCrafters runs your program.
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit early if any commands fail
+
+# Copied from .codecrafters/compile.sh
+#
+# - Edit this to change how your program compiles locally
+# - Edit .codecrafters/compile.sh to change how your program compiles remotely
+(
+  cd "$(dirname "$0")" # Ensure compile steps are run within the repository directory
+  mvn -B package -Ddir=/tmp/codecrafters-build-grep-java
+)
+
+# Copied from .codecrafters/run.sh
+#
+# - Edit this to change how your program runs locally
+# - Edit .codecrafters/run.sh to change how your program runs remotely
+exec java -jar /tmp/codecrafters-build-grep-java/codecrafters-grep.jar "$@"

course-definition.yml

@@ -21,6 +21,9 @@ languages:
   - slug: "gleam"
   - slug: "go"
   - slug: "haskell"
+  - slug: "java"
+    release_status: "alpha"
+    alpha_tester_usernames: ["andy1li"]
   - slug: "javascript"
   - slug: "kotlin"
   - slug: "python"

dockerfiles/java-23.Dockerfile

@@ -0,0 +1,13 @@
+# syntax=docker/dockerfile:1.7-labs
+FROM maven:3.9.9-eclipse-temurin-23-alpine
+
+# Ensures the container is re-built if dependency files change
+ENV CODECRAFTERS_DEPENDENCY_FILE_PATHS="pom.xml"
+
+WORKDIR /app
+
+# .git & README.md are unique per-repository. We ignore them on first copy to prevent cache misses
+COPY --exclude=.git --exclude=README.md . /app
+
+# Install language-specific dependencies
+RUN .codecrafters/compile.sh

solutions/java/01-cq2/code/.codecrafters/compile.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+#
+# This script is used to compile your program on CodeCrafters
+#
+# This runs before .codecrafters/run.sh
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit on failure
+
+mvn -B package -Ddir=/tmp/codecrafters-build-grep-java

solutions/java/01-cq2/code/.codecrafters/run.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+#
+# This script is used to run your program on CodeCrafters
+#
+# This runs after .codecrafters/compile.sh
+#
+# Learn more: https://codecrafters.io/program-interface
+
+set -e # Exit on failure
+
+exec java -jar /tmp/codecrafters-build-grep-java/codecrafters-grep.jar "$@"

solutions/java/01-cq2/code/.gitattributes

@@ -0,0 +1 @@
+* text=auto

solutions/java/01-cq2/code/.gitignore

@@ -0,0 +1,3 @@
+*.jar
+target/
+.idea/

solutions/java/01-cq2/code/README.md

@@ -0,0 +1,39 @@
+![progress-banner](https://codecrafters.io/landing/images/default_progress_banners/grep.png)
+
+This is a starting point for Java solutions to the
+["Build Your Own grep" Challenge](https://app.codecrafters.io/courses/grep/overview).
+
+[Regular expressions](https://en.wikipedia.org/wiki/Regular_expression)
+(Regexes, for short) are patterns used to match character combinations in
+strings. [`grep`](https://en.wikipedia.org/wiki/Grep) is a CLI tool for
+searching using Regexes.
+
+In this challenge you'll build your own implementation of `grep`. Along the way
+we'll learn about Regex syntax, how parsers/lexers work, and how regular
+expressions are evaluated.
+
+**Note**: If you're viewing this repo on GitHub, head over to
+[codecrafters.io](https://codecrafters.io) to try the challenge.
+
+# Passing the first stage
+
+The entry point for your `grep` implementation is in `src/main/java/Main.java`.
+Study and uncomment the relevant code, and push your changes to pass the first
+stage:
+
+```sh
+git commit -am "pass 1st stage" # any msg
+git push origin master
+```
+
+Time to move on to the next stage!
+
+# Stage 2 & beyond
+
+Note: This section is for stages 2 and beyond.
+
+1. Ensure you have `mvn` installed locally
+1. Run `./your_program.sh` to run your program, which is implemented in
+   `src/main/java/Main.java`.
+1. Commit your changes and run `git push origin master` to submit your solution
+   to CodeCrafters. Test output will be streamed to your terminal.

solutions/java/01-cq2/code/codecrafters.yml

@@ -0,0 +1,11 @@
+# Set this to true if you want debug logs.
+#
+# These can be VERY verbose, so we suggest turning them off
+# unless you really need them.
+debug: false
+
+# Use this to change the Java version used to run your code
+# on Codecrafters.
+#
+# Available versions: java-23
+language_pack: java-23

solutions/java/01-cq2/code/pom.xml

@@ -0,0 +1,52 @@
+<?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>
+
+    <groupId>io.codecrafters</groupId>
+    <artifactId>codecrafters-grep</artifactId>
+    <version>1.0</version>
+
+    <properties>
+        <maven.compiler.source>23</maven.compiler.source>
+        <maven.compiler.target>23</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <java.version>23</java.version>
+    </properties>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <configuration>
+                    <finalName>codecrafters-grep</finalName> <!-- Please do not change this final artifact name-->
+                    <descriptorRefs>
+                        <descriptorRef>jar-with-dependencies</descriptorRef>
+                    </descriptorRefs>
+                    <appendAssemblyId>false</appendAssemblyId>
+                    <archive>
+                        <manifest>
+                            <addClasspath>true</addClasspath>
+                            <!-- This is the main class of your program which will be executed-->
+                            <mainClass>Main</mainClass>
+                        </manifest>
+                    </archive>
+                    <outputDirectory>${dir}</outputDirectory>
+                </configuration>
+
+                <executions>
+                    <execution>
+                        <id>make-assembly</id>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

solutions/java/01-cq2/code/src/main/java/Main.java

@@ -0,0 +1,29 @@
+import java.io.IOException;
+import java.util.Scanner;
+
+public class Main {
+  public static void main(String[] args){
+    if (args.length != 2 || !args[0].equals("-E")) {
+      System.out.println("Usage: ./your_program.sh -E <pattern>");
+      System.exit(1);
+    }
+
+    String pattern = args[1];  
+    Scanner scanner = new Scanner(System.in);
+    String inputLine = scanner.nextLine();
+
+    if (matchPattern(inputLine, pattern)) {
+        System.exit(0);
+    } else {
+        System.exit(1);
+    }
+  }
+
+  public static boolean matchPattern(String inputLine, String pattern) {
+    if (pattern.length() == 1) {
+      return inputLine.contains(pattern);
+    } else {
+      throw new RuntimeException("Unhandled pattern: " + pattern);
+    }
+  }
+}