Revert "Use java prebuilts"

This reverts commit 193175094081e9cc3c44e2b3ee290195b1b89613.

Change-Id: I7a99fd6c53d35a2a674f2d60b113a727f3c453ce
diff --git a/core/config.mk b/core/config.mk
index 00a3c3b..f839d3d 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -675,13 +675,22 @@
 
 COLUMN:= column
 
+# We may not have the right JAVA_HOME/PATH set up yet when this is run from envsetup.sh.
+ifneq ($(CALLED_FROM_SETUP),true)
+
 # Path to tools.jar, or empty if EXPERIMENTAL_USE_OPENJDK9 is set
 HOST_JDK_TOOLS_JAR :=
 # TODO: Remove HOST_JDK_TOOLS_JAR and all references to it once OpenJDK 8
 # toolchains are no longer supported (i.e. when what is now
 # EXPERIMENTAL_USE_OPENJDK9 becomes the standard). http://b/38418220
 ifeq ($(EXPERIMENTAL_USE_OPENJDK9),)
-HOST_JDK_TOOLS_JAR := $(ANDROID_JAVA_TOOLCHAIN)/../lib/tools.jar
+HOST_JDK_TOOLS_JAR := $(shell $(BUILD_SYSTEM)/find-jdk-tools-jar.sh)
+
+ifneq ($(HOST_JDK_TOOLS_JAR),)
+ifeq ($(wildcard $(HOST_JDK_TOOLS_JAR)),)
+$(error Error: could not find jdk tools.jar at $(HOST_JDK_TOOLS_JAR), please check if your JDK was installed correctly)
+endif
+endif
 endif # ifeq ($(EXPERIMENTAL_USE_OPENJDK9),)
 
 # Is the host JDK 64-bit version?
@@ -689,6 +698,7 @@
 ifneq ($(filter 64-Bit, $(shell $(JAVA) -version 2>&1)),)
 HOST_JDK_IS_64BIT_VERSION := true
 endif
+endif  # CALLED_FROM_SETUP not true
 
 # It's called md5 on Mac OS and md5sum on Linux
 ifeq ($(HOST_OS),darwin)
@@ -838,17 +848,6 @@
 unexport JAVA_HOME
 export ANDROID_BUILD_PATHS:=$(abspath $(BUILD_SYSTEM)/no_java_path):$(ANDROID_BUILD_PATHS)
 export PATH:=$(abspath $(BUILD_SYSTEM)/no_java_path):$(PATH)
-else
-  # Put java first on the path
-  # TODO(ccross): remove this once tools run during the build no longer depend on
-  # finding java in the path
-  ifeq (,$(strip $(CALLED_FROM_SETUP)))
-    ifneq ($(shell which java),$(abspath $(ANDROID_JAVA_TOOLCHAIN)/java))
-      $(warning Found incorrect java $(shell which java) in $$PATH)
-      $(warning Adding $(abspath $(ANDROID_JAVA_TOOLCHAIN)) to $$PATH)
-      export PATH:=$(abspath $(ANDROID_JAVA_TOOLCHAIN)):$(PATH)
-    endif
-  endif
 endif
 
 # Projects clean of compiler warnings should be compiled with -Werror.