Added support for a custom config key mapping function

Author: JanHolger

src/main/java/org/javawebstack/webutils/config/Config.java

@@ -12,19 +12,15 @@ public Config set(String path, String key, String value) {
         return set(prefix + key.toLowerCase(Locale.ROOT), value);
     }
 
-    public Config add(String path, Map<String, String> data, Map<String, String> mapping) {
-        return add(path, data, k -> mapping.getOrDefault(k, k));
-    }
-
     public Config add(String path, Map<String, String> data, Function<String, String> mapping) {
-        data.forEach((key, value) -> set(path, mapping.apply(key), value));
+        data.forEach((key, value) -> {
+            key = mapping.apply(key);
+            if(key != null)
+                set(path, key, value);
+        });
         return this;
     }
 
-    public Config add(Map<String, String> data, Map<String, String> mapping) {
-        return add(null, data, mapping);
-    }
-
     public Config add(Map<String, String> data, Function<String, String> mapping) {
         return add(null, data, mapping);
     }
@@ -37,10 +33,6 @@ public Config add(Map<String, String> data) {
         return add(null, data, k -> k);
     }
 
-    public Config add(String path, EnvFile envFile, Map<String, String> mapping) {
-        return add(path, envFile.getValues(), mapping);
-    }
-
     public Config add(String path, EnvFile envFile, Function<String, String> mapping) {
         return add(path, envFile.getValues(), mapping);
     }
@@ -49,10 +41,6 @@ public Config add(String path, EnvFile envFile) {
         return add(path, envFile, k -> k);
     }
 
-    public Config add(EnvFile envFile, Map<String, String> mapping) {
-        return add(null, envFile, mapping);
-    }
-
     public Config add(EnvFile envFile, Function<String, String> mapping) {
         return add(null, envFile, mapping);
     }

src/main/java/org/javawebstack/webutils/config/Mapping.java

@@ -0,0 +1,26 @@
+package org.javawebstack.webutils.config;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Function;
+
+public class Mapping implements Function<String, String> {
+
+    private final Map<String, String> mapping = new HashMap<>();
+    private boolean failIfNotFound = false;
+
+    public Mapping failIfNotFound(boolean failIfNotFound) {
+        this.failIfNotFound = failIfNotFound;
+        return this;
+    }
+
+    public Mapping map(String from, String to) {
+        mapping.put(from, to);
+        return this;
+    }
+
+    public String apply(String s) {
+        return mapping.getOrDefault(s, failIfNotFound ? null : s);
+    }
+
+}

src/main/java/org/javawebstack/webutils/config/MappingPipeline.java

@@ -0,0 +1,19 @@
+package org.javawebstack.webutils.config;
+
+import java.util.function.Function;
+
+public class MappingPipeline implements Function<String, String> {
+
+    private final Function<String, String>[] pipeline;
+
+    public MappingPipeline(Function<String, String>... pipeline) {
+        this.pipeline = pipeline;
+    }
+
+    public String apply(String s) {
+        String k = s;
+        for(Function<String, String> mapping : pipeline)
+            k = mapping.apply(k);
+        return k == null ? s : k;
+    }
+}

src/main/java/org/javawebstack/webutils/config/MappingTryout.java

@@ -0,0 +1,27 @@
+package org.javawebstack.webutils.config;
+
+import java.util.function.Function;
+
+public class MappingTryout implements Function<String, String> {
+
+    private final Function<String, String>[] tryout;
+    private boolean failIfEqual = true;
+
+    public MappingTryout(Function<String, String>... tryout) {
+        this.tryout = tryout;
+    }
+
+    public MappingTryout failIfEqual(boolean failIfEqual) {
+        this.failIfEqual = failIfEqual;
+        return this;
+    }
+
+    public String apply(String s) {
+        for(Function<String, String> mapping : tryout) {
+            String k = mapping.apply(s);
+            if(k != null && (!failIfEqual || !k.equals(s)))
+                return k;
+        }
+        return s;
+    }
+}