improve constructor detection

Author: SentryMan

jsonb-generator/src/main/java/io/avaje/jsonb/generator/FieldReader.java

@@ -10,6 +10,7 @@ final class FieldReader {
 
   private final Map<String, TypeSubTypeMeta> subTypes = new LinkedHashMap<>();
 
+  private final Element element;
   private final FieldProperty property;
   private final String propertyName;
   private final boolean serialize;
@@ -34,13 +35,13 @@ final class FieldReader {
   }
 
   FieldReader(
-    Element element,
-    NamingConvention namingConvention,
-    TypeSubTypeMeta subType,
-    List<String> genericTypeParams,
-    Integer frequency,
-    boolean jsonCreatorPresent) {
-
+      Element element,
+      NamingConvention namingConvention,
+      TypeSubTypeMeta subType,
+      List<String> genericTypeParams,
+      Integer frequency,
+      boolean jsonCreatorPresent) {
+    this.element = element;
     num = frequency == 0 ? "" : frequency.toString();
     addSubType(subType);
     var isMethod = element instanceof ExecutableElement;
@@ -296,4 +297,7 @@ List<String> aliases() {
     return aliases;
   }
 
+  public Element element() {
+    return element;
+  }
 }

jsonb-generator/src/main/java/io/avaje/jsonb/generator/TypeReader.java

@@ -4,6 +4,8 @@
 import javax.lang.model.type.TypeMirror;
 import javax.lang.model.util.ElementFilter;
 
+import static java.util.stream.Collectors.toSet;
+
 import java.util.*;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
@@ -304,13 +306,17 @@ private void matchFieldsToSetterOrConstructor() {
   }
 
   private void matchFieldToSetter(FieldReader field) {
-    if (!matchFieldToSetter2(field, false)
+    if (hasNoSetter(field)) {
+      logError("Non public field " + baseType + " " + field.fieldName() + " with no matching setter or constructor?");
+    }
+  }
+
+  private boolean hasNoSetter(FieldReader field) {
+    return !matchFieldToSetter2(field, false)
       && !matchFieldToSetter2(field, true)
       && !matchFieldToSetterByParam(field)
       && !field.isPublicField()
-      && !field.isSubTypeField()) {
-      logError("Non public field " + baseType + " " + field.fieldName() + " with no matching setter or constructor?");
-    }
+      && !field.isSubTypeField();
   }
 
   private boolean matchFieldToSetterByParam(FieldReader field) {
@@ -458,7 +464,29 @@ private MethodReader determineConstructor() {
       // fallback to the single public constructor
       return allPublic.get(0);
     }
-    // find the largest constructor
+
+    // find the right constructor
+    var contructorFields =
+        allFields.stream()
+            .filter(FieldReader::includeFromJson)
+            .filter(this::hasNoSetter)
+            .map(f -> f.element().asType().toString())
+            .map(Util::trimAnnotations)
+            .collect(toSet());
+
+    return allPublic.stream()
+        .filter(c -> c.getParams().size() == contructorFields.size())
+        .filter(
+            c ->
+                c.getParams().stream()
+                    .map(p -> p.element().asType().toString())
+                    .map(Util::trimAnnotations)
+                    .allMatch(contructorFields::contains))
+        .findFirst()
+        .orElseGet(this::largest);
+  }
+
+  private MethodReader largest() {
     int argCount = 0;
     MethodReader largestConstructor = null;
     for (MethodReader ctor : publicConstructors) {

jsonb-generator/src/test/java/io/avaje/jsonb/generator/models/valid/MultiConstruct.java

@@ -0,0 +1,36 @@
+package io.avaje.jsonb.generator.models.valid;
+
+import java.util.List;
+
+import io.avaje.jsonb.Json;
+
+@Json
+public class MultiConstruct {
+
+  private final List<String> body;
+  private String setter;
+
+  public MultiConstruct(String string) {
+    this(List.of(string));
+  }
+
+  public MultiConstruct(List<String> body) {
+    this.body = body;
+  }
+
+  public MultiConstruct(List<String> body, int somethin) {
+    this.body = body;
+  }
+
+  public String getSetter() {
+    return setter;
+  }
+
+  public void setSetter(String setter) {
+    this.setter = setter;
+  }
+
+  public List<String> getBody() {
+    return body;
+  }
+}