Use Java 17

* Set default release version to 17
* Enable Error prone with Nullaway

Author: mpkorstanje

codegen/generators/java.rb

@@ -5,7 +5,7 @@ module Generator
   # Automatic Code generation overrides for the Java programming language
   class Java < Base
     def array_type_for(type_name)
-      "java.util.List<#{type_name}>"
+      "List<#{type_name}>"
     end
 
     def format_description(raw_description, indent_string: '')

codegen/templates/java.java.erb

@@ -2,6 +2,9 @@
 <%= class_name(key) %>.java
 package io.cucumber.messages.types;
 
+import org.jspecify.annotations.Nullable;
+
+import java.util.List;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.Optional;
@@ -17,10 +20,12 @@ import static java.util.Objects.requireNonNull;
 <%- end -%>
  */
 // Generated code
-@SuppressWarnings("unused")
+@SuppressWarnings({"unused", "JavaLangClash"})
 public final class <%= class_name(key) %> {
-  <%- schema['properties'].each do |property_name, property| -%>
-    private final <%= type_for(class_name(key), property_name, property) -%> <%= property_name %>;
+  <%- schema['properties'].each do |property_name, property| 
+      nullable = !(schema['required'] || []).index(property_name)
+  -%>
+    private final <% if nullable -%>@Nullable <%- end -%><%= type_for(class_name(key), property_name, property) -%> <%= property_name %>;
   <%- end -%>
   <%- if (schema['required'] || []).empty? -%>
   <%- schema['properties'].each do |(property_name, property)| -%>
@@ -44,8 +49,10 @@ public final class <%= class_name(key) %> {
   <%- end -%>
 
     public <%= class_name(key) %>(
-    <%- schema['properties'].each_with_index do |(property_name, property), index| -%>
-        <%= type_for(class_name(key), property_name, property) -%> <%= property_name %><%= index < schema['properties'].length-1 ? ',' : ''%>
+    <%- schema['properties'].each_with_index do |(property_name, property), index| 
+        nullable = !(schema['required'] || []).index(property_name)
+    -%>
+        <% if nullable -%>@Nullable <%- end -%><%= type_for(class_name(key), property_name, property) -%> <%= property_name %><%= index < schema['properties'].length-1 ? ',' : ''%>
     <%- end -%>
     ) {
       <%- schema['properties'].each do |(property_name, property)|

java/.mvn/jvm.config

@@ -0,0 +1,10 @@
+--add-exports jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.file=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.main=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.model=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.parser=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.processing=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.tree=ALL-UNNAMED
+--add-exports jdk.compiler/com.sun.tools.javac.util=ALL-UNNAMED
+--add-opens jdk.compiler/com.sun.tools.javac.code=ALL-UNNAMED
+--add-opens jdk.compiler/com.sun.tools.javac.comp=ALL-UNNAMED

java/pom.xml

@@ -5,7 +5,7 @@
     <parent>
         <groupId>io.cucumber</groupId>
         <artifactId>cucumber-parent</artifactId>
-        <version>4.5.0</version>
+        <version>5.0.0-SNAPSHOT</version>
     </parent>
     <artifactId>messages</artifactId>
     <version>30.1.1-SNAPSHOT</version>
@@ -53,6 +53,13 @@
     </dependencyManagement>
 
     <dependencies>
+        
+        <dependency>
+            <groupId>org.jspecify</groupId>
+            <artifactId>jspecify</artifactId>
+            <version>1.0.0</version>
+        </dependency>
+        
         <dependency>
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-databind</artifactId>

java/src/generated/java/io/cucumber/messages/types/Attachment.java

@@ -1,5 +1,8 @@
 package io.cucumber.messages.types;
 
+import org.jspecify.annotations.Nullable;
+
+import java.util.List;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.Optional;
@@ -23,32 +26,32 @@
  * is captured in `TestResult`.
  */
 // Generated code
-@SuppressWarnings("unused")
+@SuppressWarnings({"unused", "JavaLangClash"})
 public final class Attachment {
     private final String body;
     private final AttachmentContentEncoding contentEncoding;
-    private final String fileName;
+    private final @Nullable String fileName;
     private final String mediaType;
-    private final Source source;
-    private final String testCaseStartedId;
-    private final String testStepId;
-    private final String url;
-    private final String testRunStartedId;
-    private final String testRunHookStartedId;
-    private final Timestamp timestamp;
+    private final @Nullable Source source;
+    private final @Nullable String testCaseStartedId;
+    private final @Nullable String testStepId;
+    private final @Nullable String url;
+    private final @Nullable String testRunStartedId;
+    private final @Nullable String testRunHookStartedId;
+    private final @Nullable Timestamp timestamp;
 
     public Attachment(
         String body,
         AttachmentContentEncoding contentEncoding,
-        String fileName,
+        @Nullable String fileName,
         String mediaType,
-        Source source,
-        String testCaseStartedId,
-        String testStepId,
-        String url,
-        String testRunStartedId,
-        String testRunHookStartedId,
-        Timestamp timestamp
+        @Nullable Source source,
+        @Nullable String testCaseStartedId,
+        @Nullable String testStepId,
+        @Nullable String url,
+        @Nullable String testRunStartedId,
+        @Nullable String testRunHookStartedId,
+        @Nullable Timestamp timestamp
     ) {
         this.body = requireNonNull(body, "Attachment.body cannot be null");
         this.contentEncoding = requireNonNull(contentEncoding, "Attachment.contentEncoding cannot be null");

java/src/generated/java/io/cucumber/messages/types/Background.java

@@ -1,5 +1,8 @@
 package io.cucumber.messages.types;
 
+import org.jspecify.annotations.Nullable;
+
+import java.util.List;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.Optional;
@@ -11,21 +14,21 @@
  * Represents the Background message in <a href=https://github.com/cucumber/messages>Cucumber's message protocol</a>
  */
 // Generated code
-@SuppressWarnings("unused")
+@SuppressWarnings({"unused", "JavaLangClash"})
 public final class Background {
     private final Location location;
     private final String keyword;
     private final String name;
     private final String description;
-    private final java.util.List<Step> steps;
+    private final List<Step> steps;
     private final String id;
 
     public Background(
         Location location,
         String keyword,
         String name,
         String description,
-        java.util.List<Step> steps,
+        List<Step> steps,
         String id
     ) {
         this.location = requireNonNull(location, "Background.location cannot be null");
@@ -55,7 +58,7 @@ public String getDescription() {
         return description;
     }
 
-    public java.util.List<Step> getSteps() {
+    public List<Step> getSteps() {
         return steps;
     }
 

java/src/generated/java/io/cucumber/messages/types/Ci.java

@@ -1,5 +1,8 @@
 package io.cucumber.messages.types;
 
+import org.jspecify.annotations.Nullable;
+
+import java.util.List;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.Optional;
@@ -13,18 +16,18 @@
  * CI environment
  */
 // Generated code
-@SuppressWarnings("unused")
+@SuppressWarnings({"unused", "JavaLangClash"})
 public final class Ci {
     private final String name;
-    private final String url;
-    private final String buildNumber;
-    private final Git git;
+    private final @Nullable String url;
+    private final @Nullable String buildNumber;
+    private final @Nullable Git git;
 
     public Ci(
         String name,
-        String url,
-        String buildNumber,
-        Git git
+        @Nullable String url,
+        @Nullable String buildNumber,
+        @Nullable Git git
     ) {
         this.name = requireNonNull(name, "Ci.name cannot be null");
         this.url = url;

java/src/generated/java/io/cucumber/messages/types/Comment.java

@@ -1,5 +1,8 @@
 package io.cucumber.messages.types;
 
+import org.jspecify.annotations.Nullable;
+
+import java.util.List;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.Optional;
@@ -13,7 +16,7 @@
  * A comment in a Gherkin document
  */
 // Generated code
-@SuppressWarnings("unused")
+@SuppressWarnings({"unused", "JavaLangClash"})
 public final class Comment {
     private final Location location;
     private final String text;

java/src/generated/java/io/cucumber/messages/types/DataTable.java

@@ -1,5 +1,8 @@
 package io.cucumber.messages.types;
 
+import org.jspecify.annotations.Nullable;
+
+import java.util.List;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.Optional;
@@ -11,14 +14,14 @@
  * Represents the DataTable message in <a href=https://github.com/cucumber/messages>Cucumber's message protocol</a>
  */
 // Generated code
-@SuppressWarnings("unused")
+@SuppressWarnings({"unused", "JavaLangClash"})
 public final class DataTable {
     private final Location location;
-    private final java.util.List<TableRow> rows;
+    private final List<TableRow> rows;
 
     public DataTable(
         Location location,
-        java.util.List<TableRow> rows
+        List<TableRow> rows
     ) {
         this.location = requireNonNull(location, "DataTable.location cannot be null");
         this.rows = unmodifiableList(new ArrayList<>(requireNonNull(rows, "DataTable.rows cannot be null")));
@@ -28,7 +31,7 @@ public Location getLocation() {
         return location;
     }
 
-    public java.util.List<TableRow> getRows() {
+    public List<TableRow> getRows() {
         return rows;
     }
 

java/src/generated/java/io/cucumber/messages/types/DocString.java

@@ -1,5 +1,8 @@
 package io.cucumber.messages.types;
 
+import org.jspecify.annotations.Nullable;
+
+import java.util.List;
 import java.util.ArrayList;
 import java.util.Objects;
 import java.util.Optional;
@@ -11,16 +14,16 @@
  * Represents the DocString message in <a href=https://github.com/cucumber/messages>Cucumber's message protocol</a>
  */
 // Generated code
-@SuppressWarnings("unused")
+@SuppressWarnings({"unused", "JavaLangClash"})
 public final class DocString {
     private final Location location;
-    private final String mediaType;
+    private final @Nullable String mediaType;
     private final String content;
     private final String delimiter;
 
     public DocString(
         Location location,
-        String mediaType,
+        @Nullable String mediaType,
         String content,
         String delimiter
     ) {