add AttributesContainer

Author: lecousin

net.lecousin.core/src/main/java/net/lecousin/framework/util/AbstractAttributesContainer.java

@@ -0,0 +1,22 @@
+package net.lecousin.framework.util;
+
+import java.util.HashMap;
+
+/** Abstract class implementing AttributesContainer with a HashMap. */
+public abstract class AbstractAttributesContainer implements AttributesContainer {
+
+	private HashMap<String,Object> attributes = new HashMap<>(20);
+
+	@Override
+	public void setAttribute(String key, Object value) { attributes.put(key, value); }
+	
+	@Override
+	public Object getAttribute(String key) { return attributes.get(key); }
+	
+	@Override
+	public Object removeAttribute(String key) { return attributes.remove(key); }
+	
+	@Override
+	public boolean hasAttribute(String name) { return attributes.containsKey(name); }
+
+}

net.lecousin.core/src/main/java/net/lecousin/framework/util/AttributesContainer.java

@@ -0,0 +1,20 @@
+package net.lecousin.framework.util;
+
+/**
+ * Interface for objects which can store attributes.
+ */
+public interface AttributesContainer {
+
+	/** Set an attribute. */
+	void setAttribute(String name, Object value);
+	
+	/** Return the requested attribute, or null if no such attribute exists. */
+	Object getAttribute(String name);
+	
+	/** Remove and return an attribute. */
+	Object removeAttribute(String name);
+	
+	/** Return true if the given attribute is present. */
+	boolean hasAttribute(String name);
+	
+}

net.lecousin.core/src/test/java/net/lecousin/framework/core/tests/util/TestAttributesContainer.java

@@ -0,0 +1,26 @@
+package net.lecousin.framework.core.tests.util;
+
+import net.lecousin.framework.core.test.LCCoreAbstractTest;
+import net.lecousin.framework.util.AbstractAttributesContainer;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestAttributesContainer extends LCCoreAbstractTest {
+
+	@Test
+	public void test() {
+		AbstractAttributesContainer container = new AbstractAttributesContainer() {
+		};
+		Assert.assertNull(container.getAttribute("a"));
+		Assert.assertFalse(container.hasAttribute("a"));
+		container.setAttribute("a", "b");
+		Assert.assertTrue(container.hasAttribute("a"));
+		Assert.assertEquals("b", container.getAttribute("a"));
+		Assert.assertTrue(container.hasAttribute("a"));
+		Assert.assertEquals("b", container.removeAttribute("a"));
+		Assert.assertFalse(container.hasAttribute("a"));
+		Assert.assertNull(container.getAttribute("a"));
+	}
+	
+}