Normalize version numbers in FindJavaVersion (#969)

* Normalize version numbers in `FindJavaVersion`

Replace raw version strings with normalized major versions in the
`JavaVersionTable` data table. This addresses issue #968 where users
expect normalized values like "8" instead of "1.8".

- Use `getMajorVersion()` and `getMajorReleaseVersion()` instead of
  raw `getSourceCompatibility()` and `getTargetCompatibility()` fields
- Update column descriptions to clarify they contain major versions

Closes #968

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Ensure both are updated in `UpgradeToJava17Test`

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: timtebeek

src/main/java/org/openrewrite/java/migrate/search/FindJavaVersion.java

@@ -46,7 +46,9 @@ public TreeVisitor<?, ExecutionContext> getVisitor() {
             public J visitCompilationUnit(J.CompilationUnit cu, ExecutionContext ctx) {
                 cu.getMarkers().findFirst(JavaVersion.class)
                         .filter(seen::add)
-                        .map(jv -> new JavaVersionTable.Row(jv.getSourceCompatibility(), jv.getTargetCompatibility()))
+                        .map(jv -> new JavaVersionTable.Row(
+                                Integer.toString(jv.getMajorVersion()),
+                                Integer.toString(jv.getMajorReleaseVersion())))
                         .ifPresent(row -> table.insertRow(ctx, row));
                 return cu;
             }

src/main/java/org/openrewrite/java/migrate/table/JavaVersionTable.java

@@ -29,11 +29,11 @@ public JavaVersionTable(Recipe recipe) {
     @Value
     public static class Row {
         @Column(displayName = "Source compatibility",
-                description = "The version of Java used to compile the source code")
+                description = "The major version of Java used to compile the source code")
         String sourceVersion;
 
         @Column(displayName = "Target compatibility",
-                description = "The version of Java the bytecode is compiled to run on")
+                description = "The major version of Java the bytecode is compiled to run on")
         String targetVersion;
     }
 }

src/test/java/org/openrewrite/java/migrate/UpgradeToJava17Test.java

@@ -21,6 +21,7 @@
 import org.openrewrite.test.RecipeSpec;
 import org.openrewrite.test.RewriteTest;
 
+import java.util.Optional;
 import java.util.regex.Pattern;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -148,10 +149,15 @@ public String test() {
                        }
                     }
                     """,
-                  spec -> spec.afterRecipe(cu ->
-                    assertThat(cu.getMarkers().findFirst(JavaVersion.class))
-                      .map(JavaVersion::getSourceCompatibility)
-                      .hasValue("17"))
+                  spec -> spec.afterRecipe(cu -> {
+                      Optional<JavaVersion> jv = cu.getMarkers().findFirst(JavaVersion.class);
+                      assertThat(jv)
+                        .map(JavaVersion::getSourceCompatibility)
+                        .hasValue("17");
+                      assertThat(jv)
+                        .map(JavaVersion::getMajorVersion)
+                        .hasValue(17);
+                  })
                 )
               )
             ),