Remove dependency on java.beans.Introspector

This eliminates the need to include the giant java.desktop module on Java 9+.

Based on #647 by Jakob Buchgraber.

RELNOTES=Remove the need for the java.desktop module on Java 9+.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=202499735

Author: buchgr

value/src/main/java/com/google/auto/value/processor/AutoValueOrOneOfProcessor.java

@@ -36,7 +36,6 @@
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
-import java.beans.Introspector;
 import java.io.IOException;
 import java.io.Serializable;
 import java.io.Writer;
@@ -558,7 +557,7 @@ private static String nameWithoutPrefix(String name) {
       assert name.startsWith("is");
       name = name.substring(2);
     }
-    return Introspector.decapitalize(name);
+    return PropertyNames.decapitalizeLikeJavaBeans(name);
   }
 
   /**

value/src/main/java/com/google/auto/value/processor/BuilderMethodClassifier.java

@@ -29,7 +29,6 @@
 import com.google.common.collect.Iterables;
 import com.google.common.collect.LinkedListMultimap;
 import com.google.common.collect.Multimap;
-import java.beans.Introspector;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.Map;
@@ -345,7 +344,7 @@ private boolean classifyMethodOneArg(ExecutableElement method) {
       propertyName = methodName;
     } else if (valueGetter == null && methodName.startsWith("set") && methodName.length() > 3) {
       propertyNameToSetters = propertyNameToPrefixedSetters;
-      propertyName = Introspector.decapitalize(methodName.substring(3));
+      propertyName = PropertyNames.decapitalizeLikeJavaBeans(methodName.substring(3));
       valueGetter = propertyNameToGetter.get(propertyName);
       if (valueGetter == null) {
         // If our property is defined by a getter called getOAuth() then it is called "OAuth"
@@ -354,7 +353,7 @@ private boolean classifyMethodOneArg(ExecutableElement method) {
         // is defined by a getter called oAuth() then it is called "oAuth", but you would still
         // expect to be able to set it using setOAuth(x). Hence the second try using a decapitalize
         // method without the quirky two-leading-capitals rule.
-        propertyName = decapitalize(methodName.substring(3));
+        propertyName = PropertyNames.decapitalizeNormally(methodName.substring(3));
         valueGetter = propertyNameToGetter.get(propertyName);
       }
     }
@@ -550,13 +549,6 @@ private static String prefixWithSet(String propertyName) {
     return "set" + Character.toUpperCase(propertyName.charAt(0)) + propertyName.substring(1);
   }
 
-  // Equivalent to Introspector.decapitalize but without the quirky exception whereby
-  // Introspector.decapitalize("OAuth").equals("OAuth"). (If the first two letters are capitals
-  // then Introspector.decapitalize does nothing.)
-  private static String decapitalize(String propertyName) {
-    return Character.toLowerCase(propertyName.charAt(0)) + propertyName.substring(1);
-  }
-
   private String typeParamsString() {
     return TypeSimplifier.actualTypeParametersString(autoValueClass);
   }

value/src/main/java/com/google/auto/value/processor/PropertyNames.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2018 Google, Inc.
+ *
+ * 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.auto.value.processor;
+
+import com.google.common.base.Strings;
+
+/** Helper methods to create property names. */
+class PropertyNames {
+  /**
+   * Returns the {@code propertyName} with its first character in lower case, but leaves it intact
+   * if it starts with two capitals.
+   *
+   * <p>For consistency with JavaBeans, a getter called {@code getHTMLPage()} defines a property
+   * called {@code HTMLPage}. The <a
+   * href="https://docs.oracle.com/javase/8/docs/api/java/beans/Introspector.html#decapitalize-java.lang.String-">
+   * rule</a> is: the name of the property is the part after {@code get} or {@code
+   * is}, with the first letter lowercased <i>unless</i> the first two letters are uppercase. This
+   * works well for the {@code HTMLPage} example, but in these more enlightened times we use {@code
+   * HtmlPage} anyway, so the special behaviour is not useful, and of course it behaves poorly with
+   * examples like {@code OAuth}. Nevertheless, we preserve it for compatibility.
+   */
+  static String decapitalizeLikeJavaBeans(String propertyName) {
+    if (propertyName != null
+        && propertyName.length() >= 2
+        && Character.isUpperCase(propertyName.charAt(0))
+        && Character.isUpperCase(propertyName.charAt(1))) {
+      return propertyName;
+    }
+    return decapitalizeNormally(propertyName);
+  }
+
+  /**
+   * Returns the {@code propertyName} with its first character in lower case.
+   */
+  static String decapitalizeNormally(String propertyName) {
+    if (Strings.isNullOrEmpty(propertyName)) {
+      return propertyName;
+    }
+    return Character.toLowerCase(propertyName.charAt(0)) + propertyName.substring(1);
+  }
+}

value/src/test/java/com/google/auto/value/processor/PropertyNamesTest.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2018 Google, Inc.
+ *
+ * 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.auto.value.processor;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.truth.Expect;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class PropertyNamesTest {
+  @Rule public Expect expect = Expect.create();
+
+  private static final ImmutableMap<String, String> NORMAL_CASES =
+      ImmutableMap.<String, String>builder()
+          .put("Foo", "foo")
+          .put("foo", "foo")
+          .put("X", "x")
+          .put("x", "x")
+          .put("", "")
+          .build();
+  
+  @Test
+  public void decapitalizeLikeJavaBeans() {
+    NORMAL_CASES
+        .forEach(
+            (input, output) -> {
+              expect.that(PropertyNames.decapitalizeLikeJavaBeans(input)).isEqualTo(output);
+            });
+    expect.that(PropertyNames.decapitalizeLikeJavaBeans(null)).isNull();
+    expect.that(PropertyNames.decapitalizeLikeJavaBeans("HTMLPage")).isEqualTo("HTMLPage");
+    expect.that(PropertyNames.decapitalizeLikeJavaBeans("OAuth")).isEqualTo("OAuth");
+  }
+
+  @Test
+  public void decapitalizeNormally() {
+    NORMAL_CASES
+        .forEach(
+            (input, output) -> {
+              expect.that(PropertyNames.decapitalizeNormally(input)).isEqualTo(output);
+            });
+    expect.that(PropertyNames.decapitalizeNormally(null)).isNull();
+    expect.that(PropertyNames.decapitalizeNormally("HTMLPage")).isEqualTo("hTMLPage");
+    expect.that(PropertyNames.decapitalizeNormally("OAuth")).isEqualTo("oAuth");
+  }
+}