Don't require type table to exist

rewrite-java/src/main/java/org/openrewrite/java/JavaParser.java

@@ -126,12 +126,13 @@ static List<Path> dependenciesFromResources(ExecutionContext ctx, String... arti
         Set<String> missingArtifactNames = new LinkedHashSet<>(Arrays.asList(artifactNamesWithVersions));
 
         try (RewriteClasspathJarClasspathLoader rewriteClasspathJarClasspathLoader = new RewriteClasspathJarClasspathLoader(ctx)) {
-            for (JavaParserClasspathLoader locator : new JavaParserClasspathLoader[]{
-                    new TypeTable(ctx, missingArtifactNames),
-                    rewriteClasspathJarClasspathLoader,
-            }) {
+            List<JavaParserClasspathLoader> loaders = new ArrayList<>(2);
+            Optional.ofNullable(TypeTable.fromClasspath(ctx, missingArtifactNames)).ifPresent(loaders::add);
+            loaders.add(rewriteClasspathJarClasspathLoader);
+
+            for (JavaParserClasspathLoader loader : loaders) {
                 for (String missingArtifactName : new ArrayList<>(missingArtifactNames)) {
-                    Path located = locator.load(missingArtifactName);
+                    Path located = loader.load(missingArtifactName);
                     if (located != null) {
                         artifacts.add(located);
                         missingArtifactNames.remove(missingArtifactName);

rewrite-java/src/main/java/org/openrewrite/java/internal/parser/TypeTable.java

@@ -78,8 +78,12 @@ public class TypeTable implements JavaParserClasspathLoader {
 
     private static final Map<GroupArtifactVersion, Path> classesDirByArtifact = new LinkedHashMap<>();
 
-    public TypeTable(ExecutionContext ctx, Collection<String> artifactNames) {
-        this(ctx, findCaller().getClassLoader().getResourceAsStream(DEFAULT_RESOURCE_PATH), artifactNames);
+    public static @Nullable TypeTable fromClasspath(ExecutionContext ctx, Collection<String> artifactNames) {
+        try (InputStream is = findCaller().getClassLoader().getResourceAsStream(DEFAULT_RESOURCE_PATH)) {
+            return is == null ? null : new TypeTable(ctx, is, artifactNames);
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
     }
 
     public TypeTable(ExecutionContext ctx, InputStream is, Collection<String> artifactNames) {

rewrite-java/src/main/java/org/openrewrite/java/internal/parser/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2020 the original author or authors.
+ * <p>
+ * 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
+ * <p>
+ * https://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.
+ */
+@NullMarked
+package org.openrewrite.java.internal.parser;
+
+import org.jspecify.annotations.NullMarked;