How to use external jar like jsoup library in android framework [AOSP] java files (NOT Android Studio or Java IDE)

Question

I wish to use jsoup library in Android Open Source Project. For this I did two things:-

Step 1:

1. Made a directory jsoup in common as follows: [android]prebuilts/misc/common/jsoup/
2. In this jsoup folder I added jsoup-1.13.1.jar downloaded from : https://jsoup.org/download
3. In this same jsoup folder I added another file Android.mk {as it is name and code below:}

    LOCAL_PATH := $(call my-dir)  
    include $(CLEAR_VARS)  
    LOCAL_MODULE := jsoup
    LOCAL_MODULE_TAGS := optional
    LOCAL_SRC_FILES := jsoup-1.13.1.jar
    LOCAL_MODULE_CLASS := JAVA_LIBRARIES
    LOCAL_MODULE_SUFFIX := $(COMMON_JAVA_PACKAGE_SUFFIX)
    LOCAL_DEX_PREOPT := false
    include $(BUILD_PREBUILT)

Step 2:

1. Go to another make file as follows : [android]/frameworks/base/Android.mk
2. In this Android.mk file I added following line shown below (after the LOCAL_JAVA_LIBRARIES variable is set): LOCAL_STATIC_JAVA_LIBRARIES += jsoup

Problem:

1. I have added a file sample.java as follows- [android]frameworks/base/services/core/java/com/android/server/am/sample.java
2. In this sample.java file I have import statements as follows-

    import org.jsoup.Jsoup;
    import org.jsoup.nodes.Document;
    import org.jsoup.select.Elements;

3. When I build this whole modified android code, I get the following error and the build fails:

frameworks/base/services/core/java/com/android/server/am/sample.java:48: error: package org.jsoup does not exist  
frameworks/base/services/core/java/com/android/server/am/sample.java:49: error: package org.jsoup.nodes does not exist  
frameworks/base/services/core/java/com/android/server/am/sample.java:50: error: package org.jsoup.select does not exist

4. I even tried using a method mentioning Android.bp instead of Android.mk but same build error.
5. Also I am confused in naming of jar file as import statement includes org.jsoup... but jar file itself is just jsoup. (Do I have to change import statement like import jsoup ... or change name of jar file to org.jsoup...)
6. Any other method other than involving Android.mk or Android.bp is also highly acceptable.

Please, I have no idea of including external jar files in AOSP. The code works fine locally in IntelliJ IDE Java otherwise. Any help is deeply appreciated. Thanks in advance.

Answer 1

You can base your solution on some other jar already added in AOSP.
For example see ZXING library's Android.bp in external/zxing/:

java_import {
    name: "zxing-core-1.7",
    host_supported: true,
    installable: false,
    jars: ["core.jar"],
}

Then see the usage on another Makefile: :

LOCAL_STATIC_JAVA_LIBRARIES := \
    androidx-constraintlayout_constraintlayout-solver \
    androidx.lifecycle_lifecycle-runtime \
    androidx.lifecycle_lifecycle-extensions \
    guava \
    jsr305 \
    carsettings-contextual-card-protos-lite \
    carsettings-log-bridge-protos-lite \
    carsettings-logtags \
    statslog-settings \
    zxing-core-1.7

Lastly, based on the path of the file you're adding frameworks/base/services/core/java/com/android/server/am/sample.java, you're adding the library to the wrong makefile.

The one you changed (frameworks/base/Android.mk) is for making framework.jar, whereas you're trying to add a class on services.jar

The correct makefile to modify would be: frameworks/base/services/core/Android.bp