How to convert .proto file to JSON schema by using Java and its Libraries

convert .proto to .pb file or use the proto generated java classes to get the Descriptor object.

public static void main(String[] args) {
        DescriptorProtos.FileDescriptorSet fileDescriptorSet = DescriptorProtos.FileDescriptorSet.parseFrom(ProtoToJsonSchemaConverter.class.getClassLoader().getResourceAsStream("desc.pb"));

//get the Descriptors.Descriptor object from DescriptorProtos.FileDescriptorSet 

// use the generated class to get the Descriptor object
Descriptors.Descriptor descriptor = TestMessageProtos.testMessage.getDescriptor();

        
String schema = translateProtoToJsonSchema(descriptor.getFile().toProto());
}
 String translateProtoToJsonSchema(DescriptorProtos.FileDescriptorProto fileDescriptorProto) {
      
        StringBuilder jsonSchema = new StringBuilder();
        jsonSchema.append("{n");
        jsonSchema.append("  "type": "object",n");
        jsonSchema.append("  "properties": {n");

        for (DescriptorProtos.DescriptorProto message : fileDescriptorProto.getMessageTypeList()) {
            jsonSchema.append("    "" + message.getName() + "": {n");
            jsonSchema.append("      "type": "object",n");
            jsonSchema.append("      "properties": {n");

            for (DescriptorProtos.FieldDescriptorProto field : message.getFieldList()) {
                jsonSchema.append("        "" + field.getName() + "": {n");
                jsonSchema.append("          "type": "" + fieldTypeToJsonSchemaType(field.getType()) + ""n");
                jsonSchema.append("        },n");
            }

            jsonSchema.append("      }n");
            jsonSchema.append("    },n");
        }

        jsonSchema.append("  }n");
        jsonSchema.append("}");

        return jsonSchema.toString();
    }
   String fieldTypeToJsonSchemaType(DescriptorProtos.FieldDescriptorProto.Type fieldType) {
       
        switch (fieldType) {
            case TYPE_STRING:
                return "string";
            case TYPE_INT32:
            case TYPE_INT64:
                return "integer";
            case TYPE_DOUBLE:
                return "number";
            case TYPE_BOOL:
                return "boolean";
            // Add more cases for other types as needed
            default:
                return "unknown";
        }
    }