Pull apache#2287: Modernize codebase with Java improvements - functionalize DefaultModelProcessor

Author: Vincent Potucek

impl/maven-impl/src/main/java/org/apache/maven/impl/model/DefaultModelProcessor.java

@@ -22,7 +22,6 @@
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -37,7 +36,6 @@
 import org.apache.maven.api.services.xml.ModelXmlFactory;
 import org.apache.maven.api.services.xml.XmlReaderRequest;
 import org.apache.maven.api.spi.ModelParser;
-import org.apache.maven.api.spi.ModelParserException;
 
 /**
  *
@@ -97,18 +95,20 @@ public Path locateExistingPom(Path projectDirectory) {
     @Override
     public Model read(XmlReaderRequest request) throws IOException {
         Objects.requireNonNull(request, "source cannot be null");
-        Path pomFile = request.getPath();
-        if (pomFile != null) {
-            return modelParsers.stream()
-                    .flatMap(
-                            parser -> parser
-                                    .locateAndParse(pomFile.getParent(), Map.of(ModelParser.STRICT, request.isStrict()))
-                                    .stream())
-                    .findFirst()
+        return read(request, request.getPath());
+    }
+
+    private Model read(XmlReaderRequest request, Path pomFile) throws IOException {
+        return pomFile == null
+                ? doRead(request)
+                : modelParsers
+                    .stream()
+                    .map(parser -> parser.locateAndParse(pomFile.getParent(), Map.of(ModelParser.STRICT, request.isStrict())))
+                    .filter(Optional::isPresent)
+                    .map(Optional::get)
                     .map(model -> model.withPomFile(pomFile))
-                    .orElse(null);
-        }
-        return doRead(request);
+                    .findFirst()
+                    .orElse(doRead(request));
     }
 
     private Path doLocateExistingPom(Path project) {