building android error java version

I know this thread is old, but I'm working with Android 6 today, so I went through the same issue... For me, this helped:

If you want to force using Java 8, you can use this:

export EXPERIMENTAL_USE_JAVA8=1

Then make again:

m

But, as the name says, it is experimental, thus not recommended.

For me (Ubuntu 18.04.1), I had to download Java 7 (https://jdk.java.net/java-se-ri/7) and:

cd /usr/lib/jvm/
sudo tar zxf /tmp/openjdk-7u75-b13-linux-x64-18_dec_2014.tar.gz
sudo chown root:root java-se-7u75-ri -R

The above will create /usr/lib/jvm/java-se-7u75-ri and set it as owned by user and group root.

Now add it to PATH, as stated in https://source.android.com/setup/build/building#wrong-java-version:

[...] Prepend the correct JDK to the beginning of your path or remove the problematic JDK.

export PATH="/usr/lib/jvm/java-se-7u75-ri/bin:$PATH"

I also had to patch build/core/main.mk:

diff --git a/core/main.mk b/core/main.mk
index a6f829ab6..97690add0 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -153,7 +153,7 @@ javac_version := $(shell echo '$(javac_version_str)' | grep '[ "]1\.8[\. "$$]')
 else # default
 required_version := "1.7.x"
 required_javac_version := "1.7"
-java_version := $(shell echo '$(java_version_str)' | grep '^java .*[ "]1\.7[\. "$$]')
+java_version := $(shell echo '$(java_version_str)' | grep '^openjdk .*[ "]1\.7[\. "$$]')
 javac_version := $(shell echo '$(javac_version_str)' | grep '[ "]1\.7[\. "$$]')
 endif # if EXPERIMENTAL_USE_JAVA8

Note it was grep'ing for '^java .*[ "]1\.7[\. "$$]' and I changed it to '^openjdk .*[ "]1\.7[\. "$$]'.

After that, I issued m to make again.

Hope this can help someone else out there. :)

You asked for an OpenJDK 8 build but your version is java version "1.7.x" Java(TM) SE Runtime Environment (build 1.7.x) Java HotSpot(TM)

You need Java 7 like the error message states. Download OpenJdk 7, and install it. Then you need to

sudo update-alternatives --config java

sudo update-alternatives --config javac

On both of those choose 1.7 or 7 for the version. Google and XDA has this covered already... Java-8 will be used for Android N going forward, but for KK and MM, you need 7.