gnu: Add java-fasterxml-jackson-core.

* gnu/packages/java.scm (java-fasterxml-jackson-core): New variable.

gnu/packages/java.scm

@@ -5684,3 +5684,60 @@ (define-public java-fasterxml-jackson-annotations
 Jackson Data Processor, used on value and handler types.  The only annotations
 not included are ones that require dependency to the Databind package.")
     (license license:asl2.0)))
+
+(define-public java-fasterxml-jackson-core
+  (package
+    (name "java-fasterxml-jackson-core")
+    (version "2.9.1")
+    (source (origin
+              (method url-fetch)
+              (uri (string-append "https://github.com/FasterXML/"
+                                  "jackson-core/archive/"
+                                  "jackson-core-" version ".tar.gz"))
+              (sha256
+               (base32
+                "1sdfp74zvlh4xr5h5bj87yjlp6kny3i8ai9m0q3xs7f8hvmxpx09"))))
+    (build-system ant-build-system)
+    (arguments
+     `(#:jar-name "jackson-core.jar"
+       #:source-dir "src/main/java"
+       #:test-dir "src/test"
+       #:test-exclude
+       (list
+         ;; Expected failure.  pom.xml excludes these
+         "**/failing/**"
+         ;; Base classes that have no constructor for junit
+         "**/BaseTest.java"
+         "**/ConcurrencyReadTest.java"
+         "**/ManualCharAccessTest.java"
+         "**/ManualCharAccessTest.java"
+         "**/TrailingCommasTest.java"
+         "**/AsyncMissingValuesInObjectTest.java"
+         "**/AsyncMissingValuesInArrayTest.java")
+       #:phases
+       (modify-phases %standard-phases
+         (add-before 'configure 'generate-PackageVersion.java
+           (lambda _
+             (let* ((out "src/main/java/com/fasterxml/jackson/core/json/PackageVersion.java")
+                    (in (string-append out ".in")))
+               (copy-file in out)
+               (substitute* out
+                 (("@package@") "com.fasterxml.jackson.core.json")
+                 (("@projectversion@") ,version)
+                 (("@projectgroupid@") "com.fasterxml.jackson.core")
+                 (("@projectartifactid@") "jackson-core")))))
+         (add-before 'build 'copy-resources
+           (lambda _
+             (copy-recursively "src/main/resources"
+                               "build/classes")))
+         (add-before 'check 'copy-test-resources
+           (lambda _
+             (copy-recursively "src/test/resources"
+                               "build/test-classes"))))))
+    (native-inputs
+     `(("junit" ,java-junit)
+       ("hamcrest" ,java-hamcrest-core)))
+    (home-page "https://github.com/FasterXML/jackson-core")
+    (synopsis "")
+    (description "")
+    (license license:asl2.0))); found on wiki.fasterxml.com/JacksonLicensing