wip: EnvUtil

tile-util/pom.xml

@@ -55,4 +55,18 @@
         </dependency>
     </dependencies>
 
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <environmentVariables>
+                        <TILE_TEST_KEY_1>TEST</TILE_TEST_KEY_1>
+                        <TILE_SYS_KEY_1>SYS</TILE_SYS_KEY_1>
+                    </environmentVariables>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
 </project>

tile-util/src/main/java/com/power4j/tile/util/EnvUtil.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2019-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.power4j.tile.util;
+
+import lombok.experimental.UtilityClass;
+
+import java.io.PrintStream;
+import java.util.Map;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+/**
+ * @author CJ ([email protected])
+ * @since 1.0
+ */
+@UtilityClass
+public class EnvUtil {
+
+	/**
+	 * Lookup environment variables.
+	 * @param keyFilter Filter for key
+	 * @return Environment variables
+	 */
+	public Map<String, String> lookupKey(Predicate<String> keyFilter) {
+		return System.getenv()
+			.entrySet()
+			.stream()
+			.filter(entry -> keyFilter.test(entry.getKey()))
+			.collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue, (x, y) -> y));
+	}
+
+	/**
+	 * Lookup environment variables by prefix.
+	 * @param regex Key regex
+	 * @return Environment variables
+	 */
+	public Map<String, String> lookupKeyPattern(String regex) {
+		Pattern p = Pattern.compile(regex);
+		return lookupKey(key -> p.matcher(key).matches());
+	}
+
+	/**
+	 * Lookup environment variables by prefix.
+	 * @param keyPrefix Key prefix
+	 * @return Environment variables
+	 */
+	public Map<String, String> lookupKeyPrefix(String keyPrefix) {
+		return lookupKey(key -> key.startsWith(keyPrefix));
+	}
+
+	/**
+	 * Dump environment variables by prefix.
+	 * @param keyPrefix Key prefix
+	 * @param out PrintStream
+	 */
+	public void dumpKeyPrefix(String keyPrefix, PrintStream out) {
+		for (Map.Entry<String, String> entry : lookupKeyPrefix(keyPrefix).entrySet()) {
+			out.println(entry.getKey() + "=" + entry.getValue());
+		}
+	}
+
+	/**
+	 * Dump environment variables by prefix.
+	 * @param regex Key regex
+	 * @param out PrintStream
+	 */
+	public void dumpKeyPattern(String regex, PrintStream out) {
+		for (Map.Entry<String, String> entry : lookupKeyPattern(regex).entrySet()) {
+			out.println(entry.getKey() + "=" + entry.getValue());
+		}
+	}
+
+}

tile-util/src/test/java/com/power4j/tile/util/EnvUtilTest.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2019-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.power4j.tile.util;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.util.Map;
+
+/**
+ * @author CJ ([email protected])
+ * @since 1.0
+ */
+class EnvUtilTest {
+
+	private final String VALUE_TILE_TEST_KEY_1 = "TEST";
+
+	private final String VALUE_TILE_SYS_KEY_1 = "SYS";
+
+	@Test
+	void lookupKeyPattern() {
+		Map<String, String> map = EnvUtil.lookupKeyPrefix("^TILE_*$");
+		Assertions.assertEquals(VALUE_TILE_TEST_KEY_1, map.get("TILE_TEST_KEY_1"));
+		Assertions.assertEquals(VALUE_TILE_SYS_KEY_1, map.get("TILE_SYS_KEY_1"));
+	}
+
+	@Test
+	void lookupKeyPrefix() {
+		Map<String, String> map = EnvUtil.lookupKeyPrefix("TILE_");
+		Assertions.assertEquals(VALUE_TILE_TEST_KEY_1, map.get("TILE_TEST_KEY_1"));
+		Assertions.assertEquals(VALUE_TILE_SYS_KEY_1, map.get("TILE_SYS_KEY_1"));
+	}
+
+}