[Java.Interop] Fix C# warnings (#652)

Fixes 43 Nullable Reference Type warnings
Fixes CS0168 warning:
The variable 'e' is declared but never used.
Fixes 6 CA1307 warnings introduced by targeting `netcoreapp3.1`:
The behavior of 'string.IndexOf(char)' could vary based on the current user's locale settings.

Author: jpobst

src/Java.Interop/Java.Interop/JavaArray.cs

@@ -258,31 +258,31 @@ bool ICollection<T>.Remove (T item)
 thrownewNotSupportedException();
 }
 
-boolIList.Contains(objectvalue)
+boolIList.Contains(object?value)
 {
 if(valueisT)
 returnContains((T)value);
 returnfalse;
 }
 
-intIList.IndexOf(objectvalue)
+intIList.IndexOf(object?value)
 {
 if(valueisT)
 returnIndexOf((T)value);
 return-1;
 }
 
-intIList.Add(objectvalue)
+intIList.Add(object?value)
 {
 thrownewNotSupportedException();
 }
 
-voidIList.Insert(intindex,objectvalue)
+voidIList.Insert(intindex,object?value)
 {
 thrownewNotSupportedException();
 }
 
-voidIList.Remove(objectvalue)
+voidIList.Remove(object?value)
 {
 thrownewNotSupportedException();
 }

src/Java.Interop/Java.Interop/JavaException.cs

@@ -162,7 +162,7 @@ protected virtual void Dispose (bool disposing)
 }
 }
 
-publicoverrideboolEquals(objectobj)
+publicoverrideboolEquals(object?obj)
 {
 JniPeerMembers.AssertSelf(this);
 

src/Java.Interop/Java.Interop/JavaObject.cs

@@ -110,7 +110,7 @@ protected virtual void Dispose (bool disposing)
 {
 }
 
-publicoverrideboolEquals(objectobj)
+publicoverrideboolEquals(object?obj)
 {
 JniPeerMembers.AssertSelf(this);
 

src/Java.Interop/Java.Interop/JavaPrimitiveArrays.cs

@@ -7,6 +7,7 @@
 
 usingJava.Interop.Expressions;
 usingSystem.Linq.Expressions;
+usingSystem.Diagnostics.CodeAnalysis;
 
 namespaceJava.Interop{
 
@@ -246,7 +247,7 @@ public override IList<Boolean> CreateGenericValue (ref JniObjectReference refere
 (refJniObjectReferenceh,JniObjectReferenceOptionso)=>newJavaBooleanArray(refh,o));
 }
 
-publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState(IList<Boolean>value,ParameterAttributessynchronize)
+publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState([MaybeNull]IList<Boolean>value,ParameterAttributessynchronize)
 {
 returnJavaArray<Boolean>.CreateArgumentState(value,synchronize,(list,copy)=>{
 vara=copy
@@ -257,7 +258,7 @@ public override JniValueMarshalerState CreateGenericObjectReferenceArgumentState
 });
 }
 
-publicoverridevoidDestroyGenericArgumentState(IList<Boolean>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
+publicoverridevoidDestroyGenericArgumentState([AllowNull]IList<Boolean>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
 {
 JavaArray<Boolean>.DestroyArgumentState<JavaBooleanArray>(value,refstate,synchronize);
 }
@@ -422,7 +423,7 @@ public override IList<SByte> CreateGenericValue (ref JniObjectReference referenc
 (refJniObjectReferenceh,JniObjectReferenceOptionso)=>newJavaSByteArray(refh,o));
 }
 
-publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState(IList<SByte>value,ParameterAttributessynchronize)
+publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState([MaybeNull]IList<SByte>value,ParameterAttributessynchronize)
 {
 returnJavaArray<SByte>.CreateArgumentState(value,synchronize,(list,copy)=>{
 vara=copy
@@ -433,7 +434,7 @@ public override JniValueMarshalerState CreateGenericObjectReferenceArgumentState
 });
 }
 
-publicoverridevoidDestroyGenericArgumentState(IList<SByte>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
+publicoverridevoidDestroyGenericArgumentState([AllowNull]IList<SByte>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
 {
 JavaArray<SByte>.DestroyArgumentState<JavaSByteArray>(value,refstate,synchronize);
 }
@@ -598,7 +599,7 @@ public override IList<Char> CreateGenericValue (ref JniObjectReference reference
 (refJniObjectReferenceh,JniObjectReferenceOptionso)=>newJavaCharArray(refh,o));
 }
 
-publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState(IList<Char>value,ParameterAttributessynchronize)
+publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState([MaybeNull]IList<Char>value,ParameterAttributessynchronize)
 {
 returnJavaArray<Char>.CreateArgumentState(value,synchronize,(list,copy)=>{
 vara=copy
@@ -609,7 +610,7 @@ public override JniValueMarshalerState CreateGenericObjectReferenceArgumentState
 });
 }
 
-publicoverridevoidDestroyGenericArgumentState(IList<Char>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
+publicoverridevoidDestroyGenericArgumentState([AllowNull]IList<Char>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
 {
 JavaArray<Char>.DestroyArgumentState<JavaCharArray>(value,refstate,synchronize);
 }
@@ -774,7 +775,7 @@ public override IList<Int16> CreateGenericValue (ref JniObjectReference referenc
 (refJniObjectReferenceh,JniObjectReferenceOptionso)=>newJavaInt16Array(refh,o));
 }
 
-publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState(IList<Int16>value,ParameterAttributessynchronize)
+publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState([MaybeNull]IList<Int16>value,ParameterAttributessynchronize)
 {
 returnJavaArray<Int16>.CreateArgumentState(value,synchronize,(list,copy)=>{
 vara=copy
@@ -785,7 +786,7 @@ public override JniValueMarshalerState CreateGenericObjectReferenceArgumentState
 });
 }
 
-publicoverridevoidDestroyGenericArgumentState(IList<Int16>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
+publicoverridevoidDestroyGenericArgumentState([AllowNull]IList<Int16>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
 {
 JavaArray<Int16>.DestroyArgumentState<JavaInt16Array>(value,refstate,synchronize);
 }
@@ -950,7 +951,7 @@ public override IList<Int32> CreateGenericValue (ref JniObjectReference referenc
 (refJniObjectReferenceh,JniObjectReferenceOptionso)=>newJavaInt32Array(refh,o));
 }
 
-publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState(IList<Int32>value,ParameterAttributessynchronize)
+publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState([MaybeNull]IList<Int32>value,ParameterAttributessynchronize)
 {
 returnJavaArray<Int32>.CreateArgumentState(value,synchronize,(list,copy)=>{
 vara=copy
@@ -961,7 +962,7 @@ public override JniValueMarshalerState CreateGenericObjectReferenceArgumentState
 });
 }
 
-publicoverridevoidDestroyGenericArgumentState(IList<Int32>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
+publicoverridevoidDestroyGenericArgumentState([AllowNull]IList<Int32>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
 {
 JavaArray<Int32>.DestroyArgumentState<JavaInt32Array>(value,refstate,synchronize);
 }
@@ -1126,7 +1127,7 @@ public override IList<Int64> CreateGenericValue (ref JniObjectReference referenc
 (refJniObjectReferenceh,JniObjectReferenceOptionso)=>newJavaInt64Array(refh,o));
 }
 
-publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState(IList<Int64>value,ParameterAttributessynchronize)
+publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState([MaybeNull]IList<Int64>value,ParameterAttributessynchronize)
 {
 returnJavaArray<Int64>.CreateArgumentState(value,synchronize,(list,copy)=>{
 vara=copy
@@ -1137,7 +1138,7 @@ public override JniValueMarshalerState CreateGenericObjectReferenceArgumentState
 });
 }
 
-publicoverridevoidDestroyGenericArgumentState(IList<Int64>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
+publicoverridevoidDestroyGenericArgumentState([AllowNull]IList<Int64>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
 {
 JavaArray<Int64>.DestroyArgumentState<JavaInt64Array>(value,refstate,synchronize);
 }
@@ -1302,7 +1303,7 @@ public override IList<Single> CreateGenericValue (ref JniObjectReference referen
 (refJniObjectReferenceh,JniObjectReferenceOptionso)=>newJavaSingleArray(refh,o));
 }
 
-publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState(IList<Single>value,ParameterAttributessynchronize)
+publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState([MaybeNull]IList<Single>value,ParameterAttributessynchronize)
 {
 returnJavaArray<Single>.CreateArgumentState(value,synchronize,(list,copy)=>{
 vara=copy
@@ -1313,7 +1314,7 @@ public override JniValueMarshalerState CreateGenericObjectReferenceArgumentState
 });
 }
 
-publicoverridevoidDestroyGenericArgumentState(IList<Single>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
+publicoverridevoidDestroyGenericArgumentState([AllowNull]IList<Single>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
 {
 JavaArray<Single>.DestroyArgumentState<JavaSingleArray>(value,refstate,synchronize);
 }
@@ -1478,7 +1479,7 @@ public override IList<Double> CreateGenericValue (ref JniObjectReference referen
 (refJniObjectReferenceh,JniObjectReferenceOptionso)=>newJavaDoubleArray(refh,o));
 }
 
-publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState(IList<Double>value,ParameterAttributessynchronize)
+publicoverrideJniValueMarshalerStateCreateGenericObjectReferenceArgumentState([MaybeNull]IList<Double>value,ParameterAttributessynchronize)
 {
 returnJavaArray<Double>.CreateArgumentState(value,synchronize,(list,copy)=>{
 vara=copy
@@ -1489,7 +1490,7 @@ public override JniValueMarshalerState CreateGenericObjectReferenceArgumentState
 });
 }
 
-publicoverridevoidDestroyGenericArgumentState(IList<Double>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
+publicoverridevoidDestroyGenericArgumentState([AllowNull]IList<Double>value,refJniValueMarshalerStatestate,ParameterAttributessynchronize)
 {
 JavaArray<Double>.DestroyArgumentState<JavaDoubleArray>(value,refstate,synchronize);
 }

src/Java.Interop/Java.Interop/JavaProxyObject.cs

@@ -1,4 +1,4 @@
-#nullable enable
+#nullable enable
 
 usingSystem;
 usingSystem.Diagnostics.CodeAnalysis;
@@ -51,7 +51,7 @@ public override bool Equals (object? obj)
 
 publicboolEquals(JavaProxyObject?other)=>object.Equals(Value,other?.Value);
 
-publicoverridestringToString()
+publicoverridestring?ToString()
 {
 returnValue.ToString();
 }
@@ -63,8 +63,7 @@ public override string ToString ()
 returnnull;
 
 lock(CachedValues){
-JavaProxyObjectproxy;
-if(CachedValues.TryGetValue(value,outproxy))
+if(CachedValues.TryGetValue(value,outvarproxy))
 returnproxy;
 proxy=newJavaProxyObject(value);
 CachedValues.Add(value,proxy);