HeaderTransformsHelper (AWS Java SDK :: Auth 2.25.16 API)

java.lang.Object
- software.amazon.awssdk.auth.signer.internal.util.HeaderTransformsHelper

```
public final class HeaderTransformsHelper
extends Object
```
Helper class for transforming headers required during signing of headers.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static Map<String,List<String>>`	`canonicalizeSigningHeaders(Map<String,List<String>> headers)`
`static String`	`getCanonicalizedHeaderString(Map<String,List<String>> canonicalizedHeaders)`
`static String`	`trimAll(String value)`	"The Trimall function removes excess white space before and after values, and converts sequential spaces to a single space."

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - canonicalizeSigningHeaders
```
public static Map<String,List<String>> canonicalizeSigningHeaders(Map<String,List<String>> headers)
```
  - trimAll
```
public static String trimAll(String value)
```
    "The Trimall function removes excess white space before and after values, and converts sequential spaces to a single space."
    https://docs.aws.amazon.com/general/latest/gr/sigv4-create-canonical-request.html
    The collapse-whitespace logic is equivalent to:
    value.replaceAll("\\s+", " ")
    but does not create a Pattern object that needs to compile the match string; it also prevents us from having to make a Matcher object as well.
  - getCanonicalizedHeaderString
```
public static String getCanonicalizedHeaderString(Map<String,List<String>> canonicalizedHeaders)
```