Add support for deprecation level in manual metadata

This commit allows to specify a deprecation level to a manual metadata
entry. The purpose of that new attribute is to distinguish cases where
the property is still bound (default) from cases where the property no
longer exists and won't be bound.

This gives the opportunity to IDEs to still show the property as an
error and offer documentation and an action to rename it if a
replacement exists.

Closes gh-9074

spring-boot-tools/spring-boot-configuration-metadata/src/main/java/org/springframework/boot/configurationmetadata/Deprecation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2017 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -28,10 +28,24 @@ import java.io.Serializable;
 @SuppressWarnings("serial")
 public class Deprecation implements Serializable {
 
+	private Level level = Level.WARNING;
+
 	private String reason;
 
 	private String replacement;
 
+	/**
+	 * Define the {@link Level} of deprecation.
+	 * @return the deprecation level
+	 */
+	public Level getLevel() {
+		return this.level;
+	}
+
+	public void setLevel(Level level) {
+		this.level = level;
+	}
+
 	/**
 	 * A reason why the related property is deprecated, if any. Can be multi-lines.
 	 * @return the deprecation reason
@@ -59,8 +73,25 @@ public class Deprecation implements Serializable {
 
 	@Override
 	public String toString() {
-		return "Deprecation{" + "reason='" + this.reason + '\'' + ", replacement='"
-				+ this.replacement + '\'' + '}';
+		return "Deprecation{" + "level='" + this.level + '\'' + ", reason='"
+				+ this.reason + '\'' + ", replacement='" + this.replacement + '\'' + '}';
+	}
+
+	/**
+	 * Define the deprecation level.
+	 */
+	public enum Level {
+
+		/**
+		 * The property is still bound.
+		 */
+		WARNING,
+
+		/**
+		 * The property has been removed and is no longer bound.
+		 */
+		ERROR
+
 	}
 
 }

spring-boot-tools/spring-boot-configuration-metadata/src/main/java/org/springframework/boot/configurationmetadata/JsonReader.java

@@ -170,6 +170,8 @@ class JsonReader {
 		if (object.has("deprecation")) {
 			JSONObject deprecationJsonObject = object.getJSONObject("deprecation");
 			Deprecation deprecation = new Deprecation();
+			deprecation.setLevel(parseDeprecationLevel(
+					deprecationJsonObject.optString("level", null)));
 			deprecation.setReason(deprecationJsonObject.optString("reason", null));
 			deprecation
 					.setReplacement(deprecationJsonObject.optString("replacement", null));
@@ -178,6 +180,18 @@ class JsonReader {
 		return (object.optBoolean("deprecated") ? new Deprecation() : null);
 	}
 
+	private Deprecation.Level parseDeprecationLevel(String value) {
+		if (value != null) {
+			try {
+				return Deprecation.Level.valueOf(value.toUpperCase());
+			}
+			catch (IllegalArgumentException e) {
+				// let's use the default
+			}
+		}
+		return Deprecation.Level.WARNING;
+	}
+
 	private Object readItemValue(Object value) throws Exception {
 		if (value instanceof JSONArray) {
 			JSONArray array = (JSONArray) value;

spring-boot-tools/spring-boot-configuration-metadata/src/test/java/org/springframework/boot/configurationmetadata/JsonReaderTests.java

@@ -148,7 +148,7 @@ public class JsonReaderTests extends AbstractConfigurationMetadataTests {
 	public void deprecatedMetadata() throws IOException {
 		RawConfigurationMetadata rawMetadata = readFor("deprecated");
 		List<ConfigurationMetadataItem> items = rawMetadata.getItems();
-		assertThat(items).hasSize(3);
+		assertThat(items).hasSize(5);
 
 		ConfigurationMetadataItem item = items.get(0);
 		assertProperty(item, "server.port", "server.port", Integer.class, null);
@@ -157,19 +157,41 @@ public class JsonReaderTests extends AbstractConfigurationMetadataTests {
 				.isEqualTo("Server namespace has moved to spring.server");
 		assertThat(item.getDeprecation().getReplacement())
 				.isEqualTo("server.spring.port");
+		assertThat(item.getDeprecation().getLevel())
+				.isEqualTo(Deprecation.Level.WARNING);
 
 		ConfigurationMetadataItem item2 = items.get(1);
 		assertProperty(item2, "server.cluster-name", "server.cluster-name", String.class,
 				null);
 		assertThat(item2.isDeprecated()).isTrue();
-		assertThat(item2.getDeprecation().getReason()).isEqualTo(null);
-		assertThat(item2.getDeprecation().getReplacement()).isEqualTo(null);
+		assertThat(item2.getDeprecation().getReason()).isNull();
+		assertThat(item2.getDeprecation().getReplacement()).isNull();
+		assertThat(item.getDeprecation().getLevel())
+				.isEqualTo(Deprecation.Level.WARNING);
 
 		ConfigurationMetadataItem item3 = items.get(2);
 		assertProperty(item3, "spring.server.name", "spring.server.name", String.class,
 				null);
 		assertThat(item3.isDeprecated()).isFalse();
 		assertThat(item3.getDeprecation()).isEqualTo(null);
+
+		ConfigurationMetadataItem item4 = items.get(3);
+		assertProperty(item4, "spring.server-name", "spring.server-name", String.class, null);
+		assertThat(item4.isDeprecated()).isTrue();
+		assertThat(item4.getDeprecation().getReason()).isNull();
+		assertThat(item4.getDeprecation().getReplacement())
+				.isEqualTo("spring.server.name");
+		assertThat(item4.getDeprecation().getLevel())
+				.isEqualTo(Deprecation.Level.ERROR);
+
+		ConfigurationMetadataItem item5 = items.get(4);
+		assertProperty(item5, "spring.server-name2", "spring.server-name2", String.class, null);
+		assertThat(item5.isDeprecated()).isTrue();
+		assertThat(item5.getDeprecation().getReason()).isNull();
+		assertThat(item5.getDeprecation().getReplacement())
+				.isEqualTo("spring.server.name");
+		assertThat(item5.getDeprecation().getLevel())
+				.isEqualTo(Deprecation.Level.WARNING);
 	}
 
 	RawConfigurationMetadata readFor(String path) throws IOException {

spring-boot-tools/spring-boot-configuration-metadata/src/test/resources/metadata/configuration-metadata-deprecated.json

@@ -17,6 +17,22 @@
 			"name": "spring.server.name",
 			"type": "java.lang.String",
 			"deprecated": false
-		}
+		},
+    {
+      "name": "spring.server-name",
+      "type": "java.lang.String",
+      "deprecation": {
+        "level": "error",
+        "replacement": "spring.server.name"
+      }
+    },
+    {
+      "name": "spring.server-name2",
+      "type": "java.lang.String",
+      "deprecation": {
+        "level": "INVALID",
+        "replacement": "spring.server.name"
+      }
+    }
 	]
 }