aconfig: change java flag method name to camelCase

Before java code will directly use the flag name as the method name.
This change adds funciton to try the best to convert flag name to
camelCase, and then use the camelCase string as the method name in the
generated code.

Bug: 279483816
Test: atest aconfig.test aconfig.test.java
Change-Id: I45fc6df46c9d535cd38a657a41313202f9b660af

tools/aconfig/src/codegen_java.rs

@@ -86,10 +86,26 @@ fn create_class_element(package: &str, item: &Item) -> ClassElement {
         device_config_flag,
         flag_name_constant_suffix: item.name.to_ascii_uppercase(),
         is_read_write: item.permission == Permission::ReadWrite,
-        method_name: item.name.clone(),
+        method_name: format_java_method_name(&item.name),
     }
 }
 
+fn format_java_method_name(flag_name: &str) -> String {
+    flag_name
+        .split('_')
+        .filter(|&word| !word.is_empty())
+        .enumerate()
+        .map(|(index, word)| {
+            if index == 0 {
+                word.to_ascii_lowercase()
+            } else {
+                word[0..1].to_ascii_uppercase() + &word[1..].to_ascii_lowercase()
+            }
+        })
+        .collect::<Vec<String>>()
+        .join("")
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -102,17 +118,17 @@ mod tests {
         let expect_flags_content = r#"
         package com.android.aconfig.test;
         public final class Flags {
-            public static boolean disabled_ro() {
-                return FEATURE_FLAGS.disabled_ro();
+            public static boolean disabledRo() {
+                return FEATURE_FLAGS.disabledRo();
             }
-            public static boolean disabled_rw() {
-                return FEATURE_FLAGS.disabled_rw();
+            public static boolean disabledRw() {
+                return FEATURE_FLAGS.disabledRw();
             }
-            public static boolean enabled_ro() {
-                return FEATURE_FLAGS.enabled_ro();
+            public static boolean enabledRo() {
+                return FEATURE_FLAGS.enabledRo();
             }
-            public static boolean enabled_rw() {
-                return FEATURE_FLAGS.enabled_rw();
+            public static boolean enabledRw() {
+                return FEATURE_FLAGS.enabledRw();
             }
             private static FeatureFlags FEATURE_FLAGS = new FeatureFlagsImpl();
 
@@ -123,11 +139,11 @@ mod tests {
         import android.provider.DeviceConfig;
         public final class FeatureFlagsImpl implements FeatureFlags {
             @Override
-            public boolean disabled_ro() {
+            public boolean disabledRo() {
                 return false;
             }
             @Override
-            public boolean disabled_rw() {
+            public boolean disabledRw() {
                 return DeviceConfig.getBoolean(
                     "aconfig_test",
                     "com.android.aconfig.test.disabled_rw",
@@ -135,11 +151,11 @@ mod tests {
                 );
             }
             @Override
-            public boolean enabled_ro() {
+            public boolean enabledRo() {
                 return true;
             }
             @Override
-            public boolean enabled_rw() {
+            public boolean enabledRw() {
                 return DeviceConfig.getBoolean(
                     "aconfig_test",
                     "com.android.aconfig.test.enabled_rw",
@@ -151,10 +167,10 @@ mod tests {
         let expected_featureflags_content = r#"
         package com.android.aconfig.test;
         public interface FeatureFlags {
-            boolean disabled_ro();
-            boolean disabled_rw();
-            boolean enabled_ro();
-            boolean enabled_rw();
+            boolean disabledRo();
+            boolean disabledRw();
+            boolean enabledRo();
+            boolean enabledRw();
         }
         "#;
         let mut file_set = HashMap::from([
@@ -180,4 +196,12 @@ mod tests {
 
         assert!(file_set.is_empty());
     }
+
+    #[test]
+    fn test_format_java_method_name() {
+        let input = "____some_snake___name____";
+        let expected = "someSnakeName";
+        let formatted_name = format_java_method_name(input);
+        assert_eq!(expected, formatted_name);
+    }
 }