Extract interface out of JavaSignatureFormatter

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/DescriptorResolverUtils.java

@@ -109,7 +109,7 @@ public final class DescriptorResolverUtils {
         if (member instanceof JavaField && ((JavaField) member).isEnumEntry()) return true;
 
         if (!(member instanceof JavaMethod)) return false;
-        String signature = JavaSignatureFormatter.formatMethod((JavaMethod) member);
+        String signature = JavaSignatureFormatter.getInstance().formatMethod((JavaMethod) member);
 
         return "values()".equals(signature) ||
                "valueOf(java.lang.String)".equals(signature);
@@ -124,7 +124,7 @@ public final class DescriptorResolverUtils {
     }
 
     public static boolean isObjectMethod(@NotNull JavaMethod method) {
-        String signature = JavaSignatureFormatter.formatMethod(method);
+        String signature = JavaSignatureFormatter.getInstance().formatMethod(method);
         return "hashCode()".equals(signature) ||
                "equals(java.lang.Object)".equals(signature) ||
                "toString()".equals(signature);

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/kotlinSignature/JavaToKotlinMethodMap.java

@@ -57,7 +57,7 @@ public class JavaToKotlinMethodMap {
 
         Set<ClassDescriptor> allSuperClasses = DescriptorUtils.getAllSuperClasses(containingClass);
 
-        String serializedMethod = JavaSignatureFormatter.formatMethod(javaMethod);
+        String serializedMethod = JavaSignatureFormatter.getInstance().formatMethod(javaMethod);
         for (ClassData classData : classDatas) {
             String expectedSerializedFunction = classData.method2Function.get(serializedMethod);
             if (expectedSerializedFunction == null) continue;

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/resolver/PsiBasedMethodSignatureChecker.java

@@ -86,7 +86,7 @@ public class PsiBasedMethodSignatureChecker implements MethodSignatureChecker {
                       + "super class = " + superFunction.getContainingDeclaration() + "\n"
                       + "sub function = " + function + "\n"
                       + "sub class = " + function.getContainingDeclaration() + "\n"
-                      + "sub method = " + JavaSignatureFormatter.getExternalName(method) + "\n"
+                      + "sub method = " + JavaSignatureFormatter.getInstance().getExternalName(method) + "\n"
                       + "@KotlinSignature = " + SignaturesUtil.getKotlinSignature(annotationResolver, method));
         }
     }

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/structure/JavaSignatureFormatter.java

@@ -16,31 +16,26 @@
 
 package org.jetbrains.jet.lang.resolve.java.structure;
 
-import com.intellij.psi.PsiSubstitutor;
-import com.intellij.psi.util.PsiFormatUtil;
 import org.jetbrains.annotations.NotNull;
 
-import static com.intellij.psi.util.PsiFormatUtilBase.*;
-
-public class JavaSignatureFormatter {
-    private JavaSignatureFormatter() {
+public abstract class JavaSignatureFormatter {
+    public static JavaSignatureFormatter getInstance() {
+        // TODO: ServiceLoader.load
+        return new JavaSignatureFormatterImpl();
     }
 
     /**
      * @return a formatted signature of a method, showing method name and fully qualified names of its parameter types, e.g.:
      * {@code "foo(double, java.lang.String)"}
      */
-    public static String formatMethod(@NotNull JavaMethod method) {
-        return PsiFormatUtil.formatMethod(method.getPsi(), PsiSubstitutor.EMPTY, SHOW_NAME | SHOW_PARAMETERS,
-                                          SHOW_TYPE | SHOW_FQ_CLASS_NAMES);
-    }
+    @NotNull
+    public abstract String formatMethod(@NotNull JavaMethod method);
 
     /**
      * @return a formatted signature of a method, showing method's containing class, return type and parameter types, all names are fully
      * qualified, e.g.:
      * {@code "java.lang.Class boolean isAnnotationPresent(java.lang.Class<? extends java.lang.annotation.Annotation>)"}
      */
-    public static String getExternalName(@NotNull JavaMethod method) {
-        return PsiFormatUtil.getExternalName(method.getPsi());
-    }
+    @NotNull
+    public abstract String getExternalName(@NotNull JavaMethod method);
 }

compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/structure/JavaSignatureFormatterImpl.java

@@ -0,0 +1,39 @@
+/*
+ * Copyright 2010-2013 JetBrains s.r.o.
+ *
+ * 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 org.jetbrains.jet.lang.resolve.java.structure;
+
+import com.intellij.psi.PsiSubstitutor;
+import com.intellij.psi.util.PsiFormatUtil;
+import org.jetbrains.annotations.NotNull;
+
+import static com.intellij.psi.util.PsiFormatUtilBase.*;
+
+public class JavaSignatureFormatterImpl extends JavaSignatureFormatter {
+    @NotNull
+    @Override
+    public String formatMethod(@NotNull JavaMethod method) {
+        return PsiFormatUtil.formatMethod(method.getPsi(), PsiSubstitutor.EMPTY, SHOW_NAME | SHOW_PARAMETERS,
+                                          SHOW_TYPE | SHOW_FQ_CLASS_NAMES);
+    }
+
+    @NotNull
+    @Override
+    public String getExternalName(@NotNull JavaMethod method) {
+        String result = PsiFormatUtil.getExternalName(method.getPsi());
+        return result == null ? "null" : result;
+    }
+}