KT-635 Import std.java.compatibility

src/org/jetbrains/jet/j2k/Converter.java

@@ -37,6 +37,14 @@ public class Converter {
     return new File(quoteKeywords(javaFile.getPackageName()), imports, classesToClassList(javaFile.getClasses()));
   }
 
+  @NotNull
+  public static File fileToFileWithCompatibilityImport(@NotNull PsiJavaFile javaFile) {
+    final PsiImportList importList = javaFile.getImportList();
+    List<Import> imports = importList == null ? Collections.<Import>emptyList() : importsToImportList(importList.getAllImportStatements());
+    imports.add(new Import("std.java.compatibility.*"));
+    return new File(quoteKeywords(javaFile.getPackageName()), imports, classesToClassList(javaFile.getClasses()));
+  }
+
   @NotNull
   private static String quoteKeywords(@NotNull String packageName) {
     List<String> result = new LinkedList<String>();

test/org/jetbrains/jet/j2k/JavaToKotlinConverterTest.java

@@ -47,6 +47,7 @@ public class JavaToKotlinConverterTest extends LightDaemonAnalyzerTestCase {
     else if (javaFile.getParent().endsWith("/method")) actual = methodToKotlin(javaCode);
     else if (javaFile.getParent().endsWith("/class")) actual = fileToKotlin(javaCode);
     else if (javaFile.getParent().endsWith("/file")) actual = fileToKotlin(javaCode);
+    else if (javaFile.getParent().endsWith("/comp")) actual = fileToFileWithCompatibilityImport(javaCode);
 
     assert !actual.isEmpty() : "Specify what is it: file, class, method, statement or expression";
 
@@ -100,9 +101,17 @@ public class JavaToKotlinConverterTest extends LightDaemonAnalyzerTestCase {
   private static void setClassIdentifiers() {
     ClassVisitor c = new ClassVisitor();
     myFile.accept(c);
+    Converter.clearClassIdentifiers();
     Converter.setClassIdentifiers(c.getClassIdentifiers());
   }
 
+  @NotNull
+  private static String fileToFileWithCompatibilityImport(String text) throws IOException {
+    configureFromText(text);
+    setClassIdentifiers();
+    return prettify(Converter.fileToFileWithCompatibilityImport((PsiJavaFile) myFile).toKotlin());
+  }
+
   @NotNull
   private static String fileToKotlin(String text) throws IOException {
     configureFromText(text);

testData/ast/file/comp/intNullability.jav

@@ -0,0 +1,9 @@
+package demo;
+
+class Test {
+  void test() {
+    Integer i = 10;
+    Integer j = 10;
+    System.out.println(i + j);
+  }
+}

testData/ast/file/comp/intNullability.kt

@@ -0,0 +1,9 @@
+namespace demo
+import std.java.compatibility.*
+open class Test() {
+open fun test() : Unit {
+var i : Int? = 10
+var j : Int? = 10
+System.out?.println((i + j))
+}
+}