Parameter 0 of constructor in required a bean of type ‘java.lang.String’ that could not be found

Since you do not provide the public default constructor and you added your own non-default constructor the instantiation will fail. I would suggest you to define the input file path as property like @Value("${inputFilePath}").
If you need further initialization in your bean define a void method and annotate it with @PostConstruct and do the initialization within.

Add a public default constructor in your class. For example.

public User() {
}

Make sure you are using spring-boot-starter-data-jpa

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

You defined something like this:

@Component
public class InputItemReader{

   public InputItemReader(String input){
     ...
   }
}

The name of your class suggest that your object is not a bean, just a simple object. You should try to use it in classic way:

new InputItemReader(myString);

or to have a static method to process the input String.

Explanation: Spring IoC container will try to instantiate a new InputItemReader object like this :

new InputItemReader( -- WHAT TO PUT HERE? --) 

and will fail to call your constructor, because it will not know what you do actually expect and input string.

UPDATE:
Your problem can be solved by removing @Component annotation and defining the bean in a configuration like this:

@Bean
public InputItemReader inputItemReader(InputFileHeaderValidator inputFileHeaderValidator, FileAuditService fileAuditService){
    InputItemReader inputItemReader = new InputItemReader("--HERE SHOULD BE ACTUAL PATH---");
    // set the required service, a cleaner approach would be to send them via constructor
    inputItemReader.setFilteAuditService(fileAuditService);
    inputItemReader.setInputFileHeaderValidator(inputFileHeaderValidator);
    return inputItemReader;
}