Non functional Java styling changes (#10808)

* Replace explicit <Type> with <>

* Remove redundant toString() calls on String

* Use StandardCharsets.UTF_8 instead "UTF-8" string

* Simpler annotation format and redundant this

* Dont concat on empty String, use String.valueOf()

* Dont run equals on empty String

* Use string.anyMatch instead counting

* Collection add all instead iterating and adding

* Replace string contact with append chain in stringBuilders

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConfigLoader.java

@@ -45,7 +45,7 @@ public static CodegenConfig forName(String name) {
         try {
             return (CodegenConfig) Class.forName(name).getDeclaredConstructor().newInstance();
         } catch (Exception e) {
-            throw new GeneratorNotFoundException("Can't load config class with name '".concat(name) + "'\nAvailable:\n" + availableConfigs.toString(), e);
+            throw new GeneratorNotFoundException("Can't load config class with name '".concat(name) + "'\nAvailable:\n" + availableConfigs, e);
         }
     }
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenModel.java

@@ -45,9 +45,9 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public List<CodegenModel> children;
 
     // anyOf, oneOf, allOf
-    public Set<String> anyOf = new TreeSet<String>();
-    public Set<String> oneOf = new TreeSet<String>();
-    public Set<String> allOf = new TreeSet<String>();
+    public Set<String> anyOf = new TreeSet<>();
+    public Set<String> oneOf = new TreeSet<>();
+    public Set<String> allOf = new TreeSet<>();
 
     // The schema name as written in the OpenAPI document.
     public String name;
@@ -66,20 +66,20 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public boolean isAlias; // Is this effectively an alias of another simple type
     public boolean isString, isInteger, isLong, isNumber, isNumeric, isFloat, isDouble, isDate, isDateTime, isShort, isUnboundedInteger, isBoolean;
     private boolean additionalPropertiesIsAnyType;
-    public List<CodegenProperty> vars = new ArrayList<CodegenProperty>(); // all properties (without parent's properties)
-    public List<CodegenProperty> allVars = new ArrayList<CodegenProperty>(); // all properties (with parent's properties)
-    public List<CodegenProperty> requiredVars = new ArrayList<CodegenProperty>(); // a list of required properties
-    public List<CodegenProperty> optionalVars = new ArrayList<CodegenProperty>(); // a list of optional properties
-    public List<CodegenProperty> readOnlyVars = new ArrayList<CodegenProperty>(); // a list of read-only properties
-    public List<CodegenProperty> readWriteVars = new ArrayList<CodegenProperty>(); // a list of properties for read, write
-    public List<CodegenProperty> parentVars = new ArrayList<CodegenProperty>();
+    public List<CodegenProperty> vars = new ArrayList<>(); // all properties (without parent's properties)
+    public List<CodegenProperty> allVars = new ArrayList<>(); // all properties (with parent's properties)
+    public List<CodegenProperty> requiredVars = new ArrayList<>(); // a list of required properties
+    public List<CodegenProperty> optionalVars = new ArrayList<>(); // a list of optional properties
+    public List<CodegenProperty> readOnlyVars = new ArrayList<>(); // a list of read-only properties
+    public List<CodegenProperty> readWriteVars = new ArrayList<>(); // a list of properties for read, write
+    public List<CodegenProperty> parentVars = new ArrayList<>();
     public Map<String, Object> allowableValues;
 
     // Sorted sets of required parameters.
-    public Set<String> mandatory = new TreeSet<String>(); // without parent's required properties
-    public Set<String> allMandatory = new TreeSet<String>(); // with parent's required properties
+    public Set<String> mandatory = new TreeSet<>(); // without parent's required properties
+    public Set<String> allMandatory = new TreeSet<>(); // with parent's required properties
 
-    public Set<String> imports = new TreeSet<String>();
+    public Set<String> imports = new TreeSet<>();
     public boolean hasVars, emptyVars, hasMoreModels, hasEnums, isEnum, hasValidation;
     /**
      * Indicates the OAS schema specifies "nullable: true".
@@ -104,7 +104,7 @@ public class CodegenModel implements IJsonSchemaValidationProperties {
     public boolean hasOnlyReadOnly = true; // true if all properties are read-only
     public ExternalDocumentation externalDocumentation;
 
-    public Map<String, Object> vendorExtensions = new HashMap<String, Object>();
+    public Map<String, Object> vendorExtensions = new HashMap<>();
     private CodegenComposedSchemas composedSchemas;
     private boolean hasMultipleTypes = false;
 
@@ -320,7 +320,7 @@ public CodegenDiscriminator getDiscriminator() {
 
     public void setDiscriminator(CodegenDiscriminator discriminator) {
         this.discriminator = discriminator;
-        if (discriminator instanceof CodegenDiscriminator && !discriminator.getMappedModels().isEmpty()) {
+        if (discriminator != null && !discriminator.getMappedModels().isEmpty()) {
             this.hasDiscriminatorWithNonEmptyMapping = true;
         }
     }
@@ -1067,13 +1067,13 @@ public void removeAllDuplicatedProperty() {
 
     private List<CodegenProperty> removeDuplicatedProperty(List<CodegenProperty> vars) {
         // clone the list first
-        List<CodegenProperty> newList = new ArrayList<CodegenProperty>();
+        List<CodegenProperty> newList = new ArrayList<>();
         for (CodegenProperty cp : vars) {
             newList.add(cp.clone());
         }
 
-        Set<String> propertyNames = new TreeSet<String>();
-        Set<String> duplicatedNames = new TreeSet<String>();
+        Set<String> propertyNames = new TreeSet<>();
+        Set<String> duplicatedNames = new TreeSet<>();
 
         ListIterator<CodegenProperty> iterator = newList.listIterator();
         while (iterator.hasNext()) {