1 files changed, 42 insertions, 0 deletions
diff --git a/libphonenumber/src/com/google/i18n/phonenumbers/metadata/source/MultiFileModeFileNameProvider.java b/libphonenumber/src/com/google/i18n/phonenumbers/metadata/source/MultiFileModeFileNameProvider.java
new file mode 100644
index 00000000..0d9adb5e
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+++ b/libphonenumber/src/com/google/i18n/phonenumbers/metadata/source/MultiFileModeFileNameProvider.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2022 The Libphonenumber 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
+ *
+ * http://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.google.i18n.phonenumbers.metadata.source;
+
+import java.util.regex.Pattern;
+
+/**
+ * {@link PhoneMetadataFileNameProvider} implementation which appends key as a suffix to the
+ * predefined metadata file name base.
+ */
+public final class MultiFileModeFileNameProvider implements PhoneMetadataFileNameProvider {
+
+  private final String phoneMetadataFileNamePrefix;
+  private static final Pattern ALPHANUMERIC = Pattern.compile("^[\\p{L}\\p{N}]+$");
+
+  public MultiFileModeFileNameProvider(String phoneMetadataFileNameBase) {
+    this.phoneMetadataFileNamePrefix = phoneMetadataFileNameBase + "_";
+  }
+
+  @Override
+  public String getFor(Object key) {
+    String keyAsString = key.toString();
+    if (!ALPHANUMERIC.matcher(keyAsString).matches()) {
+      throw new IllegalArgumentException("Invalid key: " + keyAsString);
+    }
+    return phoneMetadataFileNamePrefix + key;
+  }
+}