add yaml support

README.md

@@ -5,16 +5,84 @@
 
 # Overview
 
-Library designed for retrieving properties set at application startup.
+Library designed for retrieving properties set at application startup. If you don't use Spring Framework/Spring Boot but
+like its configuration via yaml - you will find this library useful.
+
+# Advantages
+
+1) Lightweight, no need to pull lots of dependencies
+2) No reflection and typecasts
+3) Null safe and runtime exception free
 
 # Quick start
+
 This library is distributed via [jitpack.io](https://jitpack.io/#ArtemGet/entrys)
 
-# Supported properties
+# Supported entries
+
 1) Properties passed via -D
-2) Json files (strings, objects, arrays)
+2) Environment variables
+3) Json strings
+4) Yaml files
+
+# Examples
+
+## Properties:
+
+```java
+String prop=new EProp("your_prop_passed_via_-D").value();
+```
+
+## Environment variables:
+
+```java
+String env=new EEnv("my_env").value()
+```
+
+## Json strings:
+
+TODO add docs
+
+## Yaml files:
+
+1) Works similar to spring
+   framework [@Value](https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/beans/factory/annotation/Value.html)
+2) Supports string, number, arrays, float, boolean as value
+3) Supports default values and env injections
+4) Default yaml file config is placed under "src/main/resources/application.yaml", but is configurable
+
+```yaml
+sex: "male"
+person:
+  name: "kekus"
+  languages: [ ru,en ]
+  age: ${AGE_ENV:123}
+```
+
+#### Getting attribute:
+
+```java
+String sex=new EVal("sex").value();
+```
+
+#### Getting nested attribute:
+
+```java
+String name=new EVal("person.name").value();
+```
+
+#### Getting array
+
+```java
+List<String> languages=new ESplit(new EVal("person.languages")).value();
+```
+
+#### Getting env
+
+```java
+String age=new EVal("person.age").value();
+```
 
-TODO: 
-1) Environment variables
-2) Yaml files
-3) Properties files
+1) If there is a default value and env is not present - will return default value
+2) If there is a default value and env is present - will return value from env
+3) If default value is not present - will return value from env

pom.xml

@@ -17,6 +17,17 @@
     <java.version>21</java.version>
   </properties>
   <dependencies>
+    <dependency>
+      <groupId>com.amihaiemil.web</groupId>
+      <artifactId>eo-yaml</artifactId>
+      <version>8.0.6</version>
+      <exclusions>
+        <exclusion>
+          <groupId>javax.json</groupId>
+          <artifactId>javax.json-api</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
     <dependency>
       <groupId>org.glassfish</groupId>
       <artifactId>jakarta.json</artifactId>
@@ -27,7 +38,6 @@
       <groupId>org.cactoos</groupId>
       <artifactId>cactoos</artifactId>
       <version>0.57.0</version>
-      <scope>provided</scope>
     </dependency>
     <dependency>
       <groupId>org.hamcrest</groupId>

src/main/java/io/github/artemget/entrys/file/EFile.java

@@ -0,0 +1,63 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025. Artem Getmanskii
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package io.github.artemget.entrys.file;
+
+import io.github.artemget.entrys.ESafe;
+import io.github.artemget.entrys.EntryException;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+/**
+ * File's content entry.
+ *
+ * @since 0.4.0
+ */
+public class EFile extends ESafe<String> {
+    public EFile(final String path) {
+        this(path, StandardCharsets.UTF_8);
+    }
+
+    public EFile(final String path, final Charset charset) {
+        super(
+            () -> {
+                try {
+                    return Files.readString(Path.of(path), charset);
+                } catch (final IOException | SecurityException exception) {
+                    throw new EntryException(
+                        String.format(
+                            "Failed to load contents of file for path: '%s'",
+                            path
+                        ),
+                        exception
+                    );
+                }
+            },
+            () -> String.format("Empty file for path: '%s'", path)
+        );
+    }
+}

src/main/java/io/github/artemget/entrys/file/EVal.java

@@ -0,0 +1,134 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025. Artem Getmanskii
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package io.github.artemget.entrys.file;
+
+import com.amihaiemil.eoyaml.Node;
+import com.amihaiemil.eoyaml.Yaml;
+import com.amihaiemil.eoyaml.YamlMapping;
+import com.amihaiemil.eoyaml.YamlNode;
+import io.github.artemget.entrys.ESafe;
+import io.github.artemget.entrys.Entry;
+import io.github.artemget.entrys.EntryException;
+import io.github.artemget.entrys.operation.EContains;
+import io.github.artemget.entrys.operation.EFork;
+import io.github.artemget.entrys.operation.ESplit;
+import io.github.artemget.entrys.operation.EUnwrap;
+import io.github.artemget.entrys.system.EEnv;
+import java.io.IOException;
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Configuration properties entry.
+ * By default gets entries from "src/main/resources/application.yaml"
+ * Supports all yaml types, default values and envs passed via ${ENV}.
+ *
+ * @since 0.4.0
+ */
+public final class EVal extends ESafe<String> {
+
+    /**
+     * From yaml file at default dir.
+     *
+     * @param key Of entry
+     */
+    public EVal(final String key) {
+        this(key, "src/main/resources/application.yaml");
+    }
+
+    /**
+     * From yaml file.
+     *
+     * @param key Of entry
+     * @param path To yaml file
+     */
+    public EVal(final String key, final String path) {
+        this(key, new EFile(path));
+    }
+
+    /**
+     * Main ctor.
+     *
+     * @param key Of Entry
+     * @param content Yaml content
+     */
+    @SuppressWarnings("PMD.ConstructorOnlyInitializesOrCallOtherConstructors")
+    public EVal(final String key, final Entry<String> content) {
+        super(
+            () -> {
+                YamlMapping root;
+                try {
+                    root = Yaml.createYamlInput(content.value())
+                        .readYamlMapping();
+                } catch (final IOException | EntryException exception) {
+                    throw new EntryException(
+                        String.format("Failed to read yaml mapping for key: '%s'", key),
+                        exception
+                    );
+                }
+                String res = null;
+                final List<String> elements = new ESplit(() -> key, ".").value();
+                for (int element = 0; element < elements.size(); ++element) {
+                    if (element == elements.size() - 1) {
+                        final YamlNode value = root.value(elements.get(element));
+                        if (Node.SCALAR == value.type()) {
+                            res = EVal.ejected(value);
+                        } else if (Node.SEQUENCE == value.type()) {
+                            res = value.asSequence()
+                                .children().stream()
+                                .map(node -> node.asScalar().value())
+                                .collect(Collectors.joining(";"));
+                        }
+                    }
+                    root = root.yamlMapping(elements.get(element));
+                }
+                return res;
+            },
+            () -> String.format("Attribute for key '%s' is null", key)
+        );
+    }
+
+    private static String ejected(final YamlNode node) throws EntryException {
+        final String scalar = node.asScalar().value();
+        return new EFork<>(
+            () -> scalar.startsWith("${") && scalar.endsWith("}"),
+            new EFork<>(
+                () -> new ESplit(() -> scalar, ":").value().size() == 2,
+                new EFork<>(
+                    new EContains(new EEnv(() -> EVal.selected(scalar, 0).trim())),
+                    new EEnv(() -> EVal.selected(scalar, 0).trim()),
+                    () -> EVal.selected(scalar, 1).trim()
+                ),
+                new EEnv(new EUnwrap(scalar, "${", "}"))
+            ),
+            () -> scalar
+        ).value();
+    }
+
+    private static String selected(final String scalar, final int pos) throws EntryException {
+        return new ESplit(new EUnwrap(scalar, "${", "}"), ":")
+            .value().get(pos);
+    }
+}

src/main/java/io/github/artemget/entrys/file/package-info.java

@@ -0,0 +1,28 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024-2025. Artem Getmanskii
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/**
+ * Entries that read stuff from files.
+ */
+package io.github.artemget.entrys.file;