git - Applying git diff contents from a txt file

Question

A programmer friend sent me a txt-file, containing diff information. Like this, from the beginning of the txt-file content:

diff --git a/myfolder/MyClass.java b/myfolder/MyClass.java
index 1234aa0d0554..5678bcasas 112233
--- a/myfolder/MyClass.java
+++ b/myfodler/MyClass.java
@@ -58,7 +58,7 @@ public class MyClass{
        [somecode here]
 - [some row] 
 + [some row]       

etc.

How can I apply these changes to git by using command line or source tree? I'm quite new to git and I know you can apply .patch files. Can I convert this content to a patch file or what is the best way to do this? It is just a Java home project.

Answer 1

To apply a patch just use git apply

git apply /path/to/some-changes.patch

If you have only the diff, you can add some missing information

From: John Doe <email>
Date: Wed, 6 May 2020 22:53:29 +0200
Subject: the commit title

commit detail

diff --git a/myfolder/MyClass.java b/myfolder/MyClass.java
index 1234aa0d0554..5678bcasas 112233
[...]