Mapping spring legacy props

eng/code-quality-reports/src/main/resources/spotbugs/spotbugs-exclude.xml

@@ -2329,6 +2329,14 @@
     <Field name="azureProperties"/>
     <Bug pattern="URF_UNREAD_FIELD"/>
   </Match>
+
+  <!-- Field is initialized in postProcessEnvironment function -->
+  <Match>
+    <Class name="com.azure.spring.autoconfigure.unity.AbstractLegacyPropertyEnvironmentPostProcessor"/>
+    <Field name="environment"/>
+    <Bug pattern="UWF_FIELD_NOT_INITIALIZED_IN_CONSTRUCTOR"/>
+  </Match>
+
   <!-- The transient fields are not used if deserialization happens. -->
   <Match>
     <Class name="com.azure.identity.implementation.MsalAuthenticationAccount"/>

sdk/spring/azure-spring-boot-starter-keyvault-secrets/src/main/resources/META-INF/spring.factories

@@ -1 +1,2 @@
-org.springframework.boot.env.EnvironmentPostProcessor=com.azure.spring.keyvault.KeyVaultEnvironmentPostProcessor
+org.springframework.boot.env.EnvironmentPostProcessor=com.azure.spring.keyvault.KeyVaultEnvironmentPostProcessor,\
+com.azure.spring.keyvault.PostLegacyPropertyEnvironmentPostProcessor

sdk/spring/azure-spring-cloud-autoconfigure/src/main/java/com/azure/spring/autoconfigure/unity/AbstractLegacyPropertyEnvironmentPostProcessor.java

@@ -0,0 +1,63 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+package com.azure.spring.autoconfigure.unity;
+
+import com.azure.spring.keyvault.KeyVaultEnvironmentPostProcessor;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.env.EnvironmentPostProcessor;
+import org.springframework.core.Ordered;
+import org.springframework.core.env.ConfigurableEnvironment;
+
+import java.util.Properties;
+
+import static com.azure.spring.utils.PropertyLoader.loadProperties;
+
+/**
+ * Abstract class to convert legacy properties to the current when only legacy properties are configured,
+ * need to be executed before and after {@link KeyVaultEnvironmentPostProcessor}
+ * if {@link KeyVaultEnvironmentPostProcessor} is enabled.
+ */
+public abstract class AbstractLegacyPropertyEnvironmentPostProcessor implements EnvironmentPostProcessor, Ordered {
+
+    private static Properties springPropertyMap;
+    protected ConfigurableEnvironment environment;
+    static {
+        // Load the map of each service's legacy properties and associated current properties from classpath.
+        springPropertyMap = loadProperties("legacy-property-mapping.properties");
+    }
+
+    @Override
+    public abstract int getOrder();
+
+    @Override
+    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
+        this.environment = environment;
+        Properties legacyToCurrentMap = buildLegacyToCurrentPropertyMap();
+        Properties properties = convertLegacyPropertyToCurrent(legacyToCurrentMap);
+        setConvertedPropertyToEnvironment(properties);
+    }
+
+    protected Properties buildLegacyToCurrentPropertyMap() {
+        Properties legacyToCurrentMap = new Properties();
+        legacyToCurrentMap.putAll(springPropertyMap);
+        return legacyToCurrentMap;
+    }
+
+    /**
+     * Convert legacy properties to the current and create new {@link Properties} to store mapped current properties
+     * if only legacy properties are configured.
+     *
+     * @param legacyToCurrentMap A {@link Properties} contains a map of all legacy properties and associated current ones.
+     * @return A {@link Properties} to store mapped current properties
+     */
+    protected abstract Properties convertLegacyPropertyToCurrent(Properties legacyToCurrentMap);
+
+    /**
+     * Add the mapped current properties to application environment,
+     * of which the precedence varies in different processors.
+     *
+     * @param properties The converted current properties to be configured.
+     */
+    protected abstract void setConvertedPropertyToEnvironment(Properties properties);
+}