renamed config to variable

core/src/main/java/io/github/mmm/base/variable/VariableDefinition.java

@@ -0,0 +1,96 @@
+/* Copyright (c) The m-m-m Team, Licensed under the Apache License, Version 2.0
+ * http://www.apache.org/licenses/LICENSE-2.0 */
+package io.github.mmm.base.variable;
+
+import java.util.Map;
+
+/**
+ * Definition of a variable for a {@link VariableMap}. It is a simple container for the {@link #getName() name} of the
+ * variable with its {@link #getDefaultValue()} and its {@link #getType() type} making the
+ * {@link VariableMap#get(VariableDefinition) access of the value} type-safe.
+ *
+ * @param <T> type of the value for this option. See {@link #getType()}.
+ * @since 1.0.0
+ */
+public class VariableDefinition<T> {
+
+  private final String name;
+
+  private final Class<T> type;
+
+  private final T defaultValue;
+
+  /**
+   * The constructor.
+   *
+   * @param name the {@link #getName() name}.
+   * @param type the {@link #getType() type}.
+   */
+  public VariableDefinition(String name, Class<T> type) {
+
+    this(name, type, null);
+  }
+
+  /**
+   * The constructor.
+   *
+   * @param name the {@link #getName() name}.
+   * @param defaultValue the {@link #getDefaultValue() default value}.
+   */
+  public VariableDefinition(String name, T defaultValue) {
+
+    this(name, null, defaultValue);
+  }
+
+  /**
+   * The constructor.
+   *
+   * @param name the {@link #getName() name}.
+   * @param type the {@link #getType() type}.
+   * @param defaultValue the {@link #getDefaultValue() default value}.
+   */
+  @SuppressWarnings("unchecked")
+  public VariableDefinition(String name, Class<T> type, T defaultValue) {
+
+    super();
+    this.name = name;
+    if ((type == null) && (defaultValue != null)) {
+      this.type = (Class<T>) defaultValue.getClass();
+    } else {
+      this.type = type;
+    }
+    this.defaultValue = defaultValue;
+  }
+
+  /**
+   * @return the name of the variable used as {@link Map#containsKey(Object) key} to
+   *         {@link VariableMap#get(VariableDefinition) get its value}.
+   */
+  public String getName() {
+
+    return this.name;
+  }
+
+  /**
+   * @return the {@link Class} reflecting the value of this variable.
+   */
+  public Class<T> getType() {
+
+    return this.type;
+  }
+
+  /**
+   * @return the optional default value to use if the variable is not explicitly defined.
+   */
+  public T getDefaultValue() {
+
+    return this.defaultValue;
+  }
+
+  @Override
+  public String toString() {
+
+    return this.name;
+  }
+
+}

core/src/main/java/io/github/mmm/base/variable/VariableMap.java

@@ -0,0 +1,114 @@
+/* Copyright (c) The m-m-m Team, Licensed under the Apache License, Version 2.0
+ * http://www.apache.org/licenses/LICENSE-2.0 */
+package io.github.mmm.base.variable;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Simple wrapper for a {@link Map} of {@link VariableDefinition variables}.
+ *
+ * @since 1.0.0
+ */
+public class VariableMap {
+
+  private final Map<String, Object> map;
+
+  private final Map<String, Object> unmodifyableMap;
+
+  /**
+   * The constructor.
+   */
+  public VariableMap() {
+
+    this(new HashMap<>());
+  }
+
+  /**
+   * The constructor.
+   *
+   * @param map the raw {@link Map} with the configuration values.
+   */
+  public VariableMap(Map<String, Object> map) {
+
+    super();
+    this.map = map;
+    this.unmodifyableMap = Collections.unmodifiableMap(map);
+  }
+
+  /**
+   * @param <T> type of config value.
+   * @param variable the {@link VariableDefinition}.
+   * @return the value of the given {@link VariableDefinition}.
+   */
+  @SuppressWarnings("unchecked")
+  public <T> T get(VariableDefinition<T> variable) {
+
+    if (variable == null) {
+      return null;
+    }
+    String key = variable.getName();
+    T value = (T) this.map.get(key);
+    if ((value == null) && !this.map.containsKey(key)) {
+      value = variable.getDefaultValue();
+    }
+    return value;
+  }
+
+  /**
+   * @param variable the {@link VariableDefinition}.
+   * @return the value of the given {@link VariableDefinition}.
+   */
+  public boolean getBoolean(VariableDefinition<Boolean> variable) {
+
+    Boolean value = get(variable);
+    if (value != null) {
+      return value.booleanValue();
+    }
+    throw new IllegalStateException("The variable " + variable.getName() + " is undefined and has no default value.");
+  }
+
+  /**
+   * @param variable the {@link VariableDefinition}.
+   * @param defaultValue the additional default value returned if the variable is undefined and the given
+   *        {@link VariableDefinition} has no {@link VariableDefinition#getDefaultValue() default value}.
+   * @return the value of the given {@link VariableDefinition}.
+   */
+  public boolean getBoolean(VariableDefinition<Boolean> variable, boolean defaultValue) {
+
+    Boolean value = get(variable);
+    if (value != null) {
+      return value.booleanValue();
+    }
+    return defaultValue;
+  }
+
+  /**
+   * @param <T> type of config value.
+   * @param key the {@link VariableDefinition}.
+   * @param value the new configuration value for the given {@link VariableDefinition}.
+   * @return the old configuration value that was previously associated with the given {@link VariableDefinition}. Will
+   *         be {@code null} if no value was configured before.
+   */
+  @SuppressWarnings("unchecked")
+  public <T> T set(VariableDefinition<T> key, T value) {
+
+    return (T) this.map.put(key.getName(), value);
+  }
+
+  /**
+   * @return the raw {@link Map} with the configuration.
+   */
+  public Map<String, Object> getMap() {
+
+    return this.unmodifyableMap;
+  }
+
+  @Override
+  public String toString() {
+
+    return this.map.toString();
+  }
+
+}