[Android] 安裝 scrcpy 在 Ubuntu

之前使用 vysor 投影 Android 裝置到 Ubuntu 桌面。但可能是 chromium 沒有更新，所以一直出現 plugin not support 之類的訊息。 爬文建議使用 scrcpy。

官方教學，https://github.com/Genymobile/scrcpy
也參考這篇，https://www.linuxuprising.com/2019/03/control-android-devices-from-your.html

實際安裝步驟有點麻煩。
1. 安裝必要套件
$ sudo apt install adb ffmpeg libsdl2-2.0-0 make gcc pkg-config meson ninja-build libavcodec-dev libavformat-dev libavutil-dev libsdl2-dev

2. 用 pip 安裝 meson 和 ninja
$ sudo pip3 install meson ninja

3. 下載 scrcpy-server，並改名為 scrcpy-server*.jar
https://github.com/Genymobile/scrcpy/releases/download/v1.16/scrcpy-server-v1.16

4. 將 scrcpy 加到某目錄
$ sudo install scrcpy-server-v*.jar /usr/local/bin/scrcpy-server.jar

5. 下載 scrcpy source，目前我是裝 1.16
https://github.com/Genymobile/scrcpy/releases/tag/v1.16

6. 解開目錄後進入 scrcpy 編譯
$ meson build --buildtype release --strip -Db_lto=true -Dprebuilt_server=../scrcpy-server-v1.16.jar
$ cd build $ ninja
$ sudo ninja install

之後應該就可以用 scrcpy 或是 sudo scrcpy 投影啦～

[Android] Screencasting

http://www.upubuntu.com/2015/09/screencastingmirroring-android-device.html

[Android] AndroidScreencast

因為 ubuntu 版本是 10.04 LTS 太舊了, 所以一堆問題要解決

要把 Android 的畫面打到 ubuntu 應該要有一堆方法, 記得之前用 Droid@Screen, 可是現在不知道怎麼了不能用

後來又看到 AndroidScreencast, 雖然感覺有點慢也將就著用吧

$ git clone https://github.com/xSAVIKx/AndroidScreencast
$ cd AndroidScreencast
$ mvn package

馬上報錯, 因為沒有裝 maven

$ sudo apt-get install maven2

結果軟體最低限制 Java 7 and Maven 3.2.5, 只好想辦法裝 maven3

因為沒有 apt, 只好抓 binary, 參考這篇文章, 可是現在只剩下 maven-3.2.2, 就加減用吧

再來是修改環境變數 JAVA_HOME, M2_HOME, MAVEN_HOME, M2 一堆

修改完還要把 maven2 移除掉才行

$ sudo apt-get autoremove maven2

確認版本
$ mvn -v
Apache Maven 3.2.2

終於可以編譯了

$ mvn package

編譯完成後執行發現又錯, 錯誤訊息在 app.properties, 要把

adb.path=adb.exe

改為

adb.path=adb

記得 adb 也要 export 到環境變數, 我是用鳥鳥的 appinventor 帶的 adb

最後終於可以執行了

$ java -jar target/androidscreencast-0.0.7s-executable.jar

唉, 舊版本就是該死

[Android] Native + Web on Android

今天在找一些Webkit的資料時,發現對岸的分享《淘宝客户端 for Android》项目实战, 先做個紀錄

[Android] htcDev

我lag了嗎?

今年六月HTC在Uplinq 2011的keynote宣佈要開放SenseUI的SDK,不過今天我才發現可以下載了... 目前還有unlock的bootloader和kernel source,未來應該會提供更多的資源吧,例如他們的app?

[Android] Install an App in Android

1.從Android外部安裝

foobar@ubuntu:~$ adb install app.apk

將安裝到/data/app目錄下,並建立{yourapp.package.main}目錄

2.從Android內部安裝

foobar@ubuntu:~$ adb shell
# pm install /path/to/app.apk

將安裝到/data/app目錄下,並建立yourapp.package.main目錄

3.從Android外部上傳後,由系統(PackageManager)啟動時自行安裝

foobar@ubuntu:~$ adb push app.apk [/data/app | /system/app]

如果push到/system/app下,則無法透過系統設定中的Manage applications移除,如果push到/data/app下,使用者可移除該app

reference: What does `adb install' do under the hood?

[Android] Compile Android module

1.add environment variables

$ cd /path/to/android
$ cd build
$ . envsetup.sh
$ help

Invoke ". build/envsetup.sh" from your shell to add the following functions to your environment:
- croot:   Changes directory to the top of the tree.
- m:       Makes from the top of the tree.
- mm:      Builds all of the modules in the current directory.
- mmm:     Builds all of the modules in the supplied directories.
- cgrep:   Greps on all local C/C++ files.
- jgrep:   Greps on all local Java files.
- resgrep: Greps on all local res/*.xml files.
- godir:   Go to the directory containing a file.

Look at the source to view more functions. The complete list is:
add_lunch_combo cgrep check_product check_variant choosecombo chooseproduct choosetype choosevariant cproj croot findmakefile gdbclient get_abs_build_var getbugreports get_build_var getprebuilt gettop godir help isviewserverstarted jgrep lunch m mm mmm pid printconfig print_lunch_menu resgrep runhat runtest setpaths set_sequence_number set_stuff_for_environment settitle smoketest startviewserver stopviewserver systemstack tapas tracedmdump

2.using mmm to compile module under root path

$ cd /path/to/android
$ mmm external/ping

============================================
PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=2.2.1
TARGET_PRODUCT=generic
TARGET_BUILD_VARIANT=eng
TARGET_SIMULATOR=
TARGET_BUILD_TYPE=release
TARGET_BUILD_APPS=
TARGET_ARCH=arm
HOST_ARCH=x86
HOST_OS=linux
HOST_BUILD_TYPE=release
BUILD_ID=MASTER
============================================
target Non-prelinked: ping (out/target/product/generic/symbols/system/bin/ping)
Install: out/target/product/generic/system/bin/ping

2.or using mm to compile module under module path

$ cd /path/to/android
$ cd development/samples/NotePad
$ mm

============================================
PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=2.2.1
TARGET_PRODUCT=generic
TARGET_BUILD_VARIANT=eng
TARGET_SIMULATOR=
TARGET_BUILD_TYPE=release
TARGET_BUILD_APPS=
TARGET_ARCH=arm
HOST_ARCH=x86
HOST_OS=linux
HOST_BUILD_TYPE=release
BUILD_ID=MASTER
============================================
Copying: out/target/common/obj/APPS/NotePad_intermediates/classes-full-debug.jar
Install: out/target/product/generic/system/app/NotePad.apk
Copying: out/target/common/obj/APPS/NotePadTests_intermediates/classes-full-debug.jar
Install: out/target/product/generic/data/app/NotePadTests.apk

2.or using make to compile module under root path

$ cd /path/to/android
$ make Phone

PLATFORM_VERSION_CODENAME=REL
PLATFORM_VERSION=2.2.1
TARGET_PRODUCT=generic
TARGET_BUILD_VARIANT=eng
TARGET_SIMULATOR=
TARGET_BUILD_TYPE=release
TARGET_BUILD_APPS=
TARGET_ARCH=arm
HOST_ARCH=x86
HOST_OS=linux
HOST_BUILD_TYPE=release
BUILD_ID=MASTER
============================================
Install: out/host/linux-x86/bin/aapt
Install: out/host/linux-x86/bin/aidl
Copying: out/target/common/obj/JAVA_LIBRARIES/core_intermediates/classes-full-debug.jar
Install: out/host/linux-x86/framework/dx.jar
Install: out/host/linux-x86/bin/dx
Copying: out/target/common/obj/JAVA_LIBRARIES/ext_intermediates/classes-full-debug.jar
Copying: out/target/common/obj/JAVA_LIBRARIES/framework_intermediates/classes-full-debug.jar
Copying: out/target/common/obj/APPS/Phone_intermediates/classes-full-debug.jar
Install: out/host/linux-x86/framework/signapk.jar
Install: out/host/linux-x86/bin/zipalign
target Package: Phone (out/target/product/generic/obj/APPS/Phone_intermediates/package.apk)
 'out/target/common/obj/APPS/Phone_intermediates/classes.dex' as 'classes.dex'...
Install: out/target/product/generic/system/app/Phone.apk

[Android] Create a fake character device driver

1.download Android kernel, details in here

2.get the current kernel configuration from the emulator

$ adb pull /proc/config.gz .
$ gunzip config.gz
$ mv config .config

3.modify .config file

$ vim .config

CONFIG_MODULES=y

4.modify kernel Makefile

$ vim Makefile

# Use --build-id when available.
#LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\
#           $(call ld-option, -Wl$(comma)--build-id,))

5.compile kernel

$ make mrproper
$ sudo make ARCH=arm CROSS_COMPILE={/path/to/android}/prebuilt/linux-x86/toolchain/arm-eabi-4.4.0/bin/arm-eabi-

6.get kernel image

Kernel: arch/arm/boot/Image is ready
Kernel: arch/arm/boot/zImage is ready

7.create fake driver, devone.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <asm/uaccess.h>

MODULE_LICENSE("Dual BSD/GPL");

static int devone_devs = 1; /* device count */
static int devone_major = 0; /* dynamic allocation */
static int devone_minor = 0;
static struct cdev devone_cdev;

ssize_t devone_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
{
  int i;
  unsigned char val = 0xff;
  int retval;

  for (i = 0 ; i < count ; i++) {
    if (copy_to_user(&buf[i], &val, 1)) {
      retval = -EFAULT;
      goto out;
    }
  }

  retval = count;
out:
  return (retval);
}

struct file_operations devone_fops = {
  .read = devone_read,
};

8.write fake driver Makefile

KERNELDIR={/path/to/android}/kernel
PWD := $(shell pwd)
obj-m := devone.o
modules:
  make -C $(KERNELDIR) M=$(PWD) modules
clean:
  rm -rf *.o *~ core.depend .*.cmd *.ko *.mod.c .tmp_versions modules.* Module*

9.compile kernel module

$ sudo make ARCH=arm CROSS_COMPILE={/path/to/android}/prebuilt/linux-x86/toolchain/arm-eabi-4.4.0/bin/arm-eabi-

10.start the emulator with our kernel

$ emulator -avd {name} -partition-size {number} -kernel {/path/to/kernel/zImage}

11.put busybox into emulator

$ adb push busybox /system/bin
$ adb shell chmod 755 /system/bin/busybox

12.put ko into emulator

$ adb remount
$ adb push devone.ko /system/lib

13.insert kernel module in emulator

$ adb shell
# insmod devone.ko
# lsmod

devone 1784 - - Live 0xbf000000

14.check the major number of devone

# cat /proc/devices

...
136 pts
252 devone
253 ttyS
...

15.insert the device node of devone

# /system/bin/busybox mknod /dev/devone c 252 0
# /system/bin/busybox ls /dev/

...
device-mapper       tty20               tty51
devone              tty21               tty52
eac                 tty22               tty53
...

# /system/bin/busybox ls -al /dev/devone

crw-rw-rw-    1 0        0        252,   0 Jan  4 05:33 /dev/devone

reference:
* 實作一個假的character driver 在emulator上跑
* Writing your first kernel module

[Android] Install Android market in Android emulator 2.2

使用SDK下載回來的avd:
1.Download Android market apk

$ wget http://goo.gl/dz3ZB

2.Create froyo AVD

$ android create avd --target 8 --name froyo

3.Start emulator

$ emulator -avd froyo -partition-size 96

3.Modified build.prop and comment "ro.config.nocheckin=yes"

$ adb pull /system/build.prop
$ vim build.prop

#ro.config.nocheckin=yes

4.Restore to system

$ adb remount /system
$ adb push build.prop /system

5.Remove SdkSetup.apk

$ adb shell rm /system/app/SdkSetup.apk
$ adb push GoogleServicesFramework.apk /system/app
$ adb push Vending.apk /system/app

6.Shut down the emulator

$ adb reboot

7.Remove emulator image

$ cd /path/to/avd
$ rm userdata-qemu.img userdata.img cache.img

8.Restart emulator


使用自己編出來的system.img:
1.直接安裝Vending.apk和GoogleServicesFramework.apk就好了

$ adb install GoogleServicesFramework.apk
$ adb install Vending.apk

2.Restart emulator

reference:
* [Android]在SDK 2.2模擬器中安裝Market

[Android] Build Android bootchart

bootchart是一套可視覺化分析GNU/Linux啟動過程的工具,它可蒐集啟動的資訊,並產生PNG/SVG/EPS等格式的圖檔,提供我們做進一步的效能分析,以下簡述安裝過程:

1.安裝bootchart工具

$ sudo apt-get install bootchart

2.重新編譯init(讓init支援bootchart)
切換到Android source code目錄下

$ cd /path/to/android

改變init系統時間

$ touch system/core/init/init.c

載入Android bash工具

$ . build/envsetup.sh

編譯init模組

$ m INIT_BOOTCHART=true

啟動機器

$ emulator -system {/path/to}/system.img -data {/path/to}/userdata.img -ramdisk {/path/to}/ramdisk.img

設定init的time out

$ adb shell 'echo 180 > /data/bootchart-start'
$ adb shell 'mkdir /data/bootchart'

3.重新啟動機器

$ adb reboot

4.重新開機完成後檢視是否有紀錄

$ adb shell ls /data/bootchart

header
kernel_pacct
proc_diskstats.log
proc_ps.log
proc_stat.log

5.下載開機紀錄

$ cd /whatever/path
$ adb pull /data/bootchart/header
$ adb pull /data/bootchart/kernel_pacct
$ adb pull /data/bootchart/proc_diskstats.log
$ adb pull /data/bootchart/proc_ps.log
$ adb pull /data/bootchart/proc_stat.log

6.產生bootchart.tgz

$ {path/to/android}/system/core/init/grab-bootchart.sh

7.產生bootchart圖檔

$ java -jar /usr/share/bootchart/bootchart.jar bootchart.tgz

Parsing /tmp/android-bootchart/bootchart.tgz
Wrote image: ./bootchart.png

如果沒有/usr/share/bootchar/bootchart.jar這個檔案,可以在這裡取得source,解開後執行ant將會編出bootchart.jar

reference:
* Build Android Bootchart
* Using Bootchart on Android

[Android] Modify ramdisk.img on Android

ramdisk.img

A small partition image with gzipped cpio archive that is mounted read-only by the kernel at boot time. It only contains /init and a few config files. It is used to start init which will mount the rest of the system images properly and run the init procedure. A Ramdisk is a standard Linux feature.

system.img

A partition image that will be mounted as /system and thus contains all system binaries

userdata.img

A partition image that can be mounted as /data and thus contains all application-specific and user-specific data.

Here is the steps:
1.Change directory to whatever/path

$ cd whatever/path

2.Copy the original ramdisk.img

$ cp /path/to/ramdisk.img .

3.Create a temporary folder, say ramdisk-ext

$ mkdir ramdisk-ext

4.Change directory to ramdisk-ext

$ cd ramdisk-ext

5.Extract the ramdisk.cpio in the ramdisk-ext folder

$ gunzip -dcv ../ramdisk.img | cpio -idm

6.Check out the directories in ramdisk.img

$ ls

data          dev   init.goldfish.rc  proc  sys
default.prop  init  init.rc           sbin  system

7.Do some modifications

$ touch foo
$ mkdir bar

8.Recreate the ramdisk.cpio

$ find . | cpio -H newc -o | gzip -9 >../ramdisk.img

9.Start the emulator

$ emulator -system system.img -data userdata.img -ramdisk ramdisk.img

10.Check out the directories in the emulator

$ adb shell ls -l

drwxrwxrwt root     root              2010-11-26 16:54 sqlite_stmt_journals
drwxrwx--- system   cache             2010-11-26 16:54 cache
d--------- system   system            2010-11-26 16:54 sdcard
lrwxrwxrwx root     root              2010-11-26 16:54 etc -> /system/etc
drwxr-xr-x root     root              2010-11-15 07:33 system
drwxr-xr-x system   system            2010-11-26 16:53 bar
drwxr-x--- system   system            2010-11-26 16:52 sbin
-rwxr-x--- system   system       1677 1970-01-01 00:00 init.goldfish.rc
dr-xr-xr-x root     root              1970-01-01 00:00 proc
-rw-r--r-- system   system          0 2010-11-26 16:52 foo
-rwxr-x--- system   system     106696 1970-01-01 00:00 init
-rwxr-x--- system   system      10700 1970-01-01 00:00 init.rc
drwxr-xr-x root     root              1970-01-01 00:00 sys
-rw-r--r-- system   system        118 1970-01-01 00:00 default.prop
drwxrwx--x system   system            2010-11-16 09:04 data
drwx------ root     root              2009-08-07 03:35 root
drwxr-xr-x root     root              2010-11-26 16:54 dev

gunzip options:

-c, --stdout      write on standard output, keep original files unchanged
-d, --decompress  decompress
-v, --verbose     verbose mode
-1, --fast        compress faster
-9, --best        compress better

cpio options:

-i, --extract                    Extract files from an archive (run in copy-in mode)
-d, --make-directories           Create leading directories where needed
-m, --preserve-modification-time Retain previous file modification times when creating files
-H, --format=FORMAT              Use given archive FORMAT
-c                               Use the old portable (ASCII) archive format
-o, --create                     Create the archive (run in copy-out mode)
-v, --verbose                    Verbosely list the files processed
-B                               Set the I/O block size to 5120 bytes
-u, --unconditional              Replace all files unconditionally

Examples:
  cpio -covB  > [file|device]<== Backup
  cpio -icduv < [file|device]<== Restore

"-H newc" use the new (SVR4) portable format. If you wish the old portable (ASCII) archive format, use "-H odc" instead. 

reference:
* Android ramdisk.img system.img userdata.img
* android ramdisk的壓縮與解壓縮

[Android] 在Android shell以Dalvik VM執行Java應用程式

由於Android上的Java程式需要在Dalvik VM下才能執行,因此Android上的App就是透過Zygote去fork出child process去執行,但如果我們希望可以直接在Android的shell下執行Java應用程式,需要一些小技巧

1.撰寫Java測試程式HelloWorld.java

//
// HelloWorld.java
//
public class HelloWorld {
    public static void main(String args[]) {
        System.out.println("Hello World!!\n");
    }   
}

2.編譯HelloWorld.java

$ javac HelloWorld.java

3.將dx設在環境變數路徑

$ export PATH={path/to/sdk}/platforms/{android-platform-number}/tools:$PATH

4.以dx工具將bytecode轉成Dalvik executable format(.dex)格式的jar

$ dx --dex --output=helloworld.jar HelloWorld.class

5.上傳到模擬器

$ adb push helloworld.jar /data

6.在Android shell下執行

$ adb shell
# /system/bin/dalvikvm -cp /data/helloworld.jar HelloWorld
Hello World!!

[Tips] Run Android application from command line

syntax:

# am start -a android.intent.action.MAIN -n package/class_fullname

example:

# am start -a android.intent.action.MAIN -n my.demo/my.demo.HelloWorld

usage:

usage: am [subcommand] [options]

    start an Activity: am start [-D] [-W] 
        -D: enable debugging
        -W: wait for launch to complete

    start a Service: am startservice 

    send a broadcast Intent: am broadcast 

    start an Instrumentation: am instrument [flags] 
        -r: print raw results (otherwise decode REPORT_KEY_STREAMRESULT)
        -e  : set argument  to 
        -p : write profiling data to 
        -w: wait for instrumentation to finish before returning

    start profiling: am profile  start 
    stop profiling: am profile  stop

     specifications include these flags:
        [-a ] [-d ] [-t ]
        [-c  [-c ] ...]
        [-e|--es   ...]
        [--esn  ...]
        [--ez   ...]
        [-e|--ei   ...]
        [-n ] [-f ]
        [--grant-read-uri-permission] [--grant-write-uri-permission]
        [--debug-log-resolution]
        [--activity-brought-to-front] [--activity-clear-top]
        [--activity-clear-when-task-reset] [--activity-exclude-from-recents]
        [--activity-launched-from-history] [--activity-multiple-task]
        [--activity-no-animation] [--activity-no-history]
        [--activity-no-user-action] [--activity-previous-is-top]
        [--activity-reorder-to-front] [--activity-reset-task-if-needed]
        [--activity-single-top]
        [--receiver-registered-only] [--receiver-replace-pending]
        []

reference: Run Android Application from Command Line

[Android] Build the linux kernel and Android source for the emulator

Build linux kerenl(Eclair):
1.check current kernel version of emulator

$ adb shell
# cat /proc/version
Linux version 2.6.29-00261-g0097074-dirty (digit@digit.mtv.corp.google.com) (gcc version 4.4.0 (GCC) ) #20 Wed Mar 31 09:54:02 PDT 2010

2.download kernel source

$ git clone git://android.git.kernel.org/kernel/common

3.check branch

$ git branch
* android-2.6.27

if it shows * android-2.6.27, list all remote available branches

$ git branch -r
origin/HEAD -> origin/android-2.6.27
origin/android-2.6.25
origin/android-2.6.27
origin/android-2.6.29
origin/android-2.6.32
origin/android-2.6.35
origin/android-2.6.36
origin/android-goldfish-2.6.27
origin/android-goldfish-2.6.29

4.switch branch

$ git checkout --track -b android-goldfish-2.6.29 origin/android-goldfish-2.6.29

5.check branch again

$ git branch
android-2.6.27
* android-goldfish-2.6.29

6.obtain kernel configuration

$ cd /path/to/kernel/common
$ adb pull /proc/config.gz .
$ gunzip config.gz
$ cp config .config

7.building and compiling the kernel

$ ARCH=arm CROSS_COMPILE=/path/to/android/prebuilt/linux-x86/toolchain/arm-eabi-4.4.0/bin/arm-eabi- make

8.successful message

Kernel: arch/arm/boot/Image is ready
Kernel: arch/arm/boot/zImage is ready

Build Android source:
1.building and compiling Android source

$ PATH=/path/to/android/prebuilt/linux-x86/toolchain/arm-eabi-4.4.0/bin
$ cd /path/to/android/
$ make

2.successful message

Install system fs image: out/target/product/generic/system.img
Target ram disk: out/target/product/generic/ramdisk.img
Target userdata fs image: out/target/product/generic/userdata.img

Start emulator:

$ emulator -kernel /path/to/kernel/common/arch/arm/boot/zImage -show-kernel -verbose -image /path/to/android/out/target/product/generic/system.img -data /path/to/android/out/target/product/generic/userdata.img -ramdisk /path/to/android/out/target/product/generic/ramdisk.img

reference:
* Howto BUILD the LINUX KERNEL for the ANDROID EMULATOR (Eclair version)
* Building Android kernel images
* 編譯android原始碼到模擬器上執行

[Tips] Some problems you may meet when compiling Android

OS: Ubuntu 10.04

編譯Donut:

development/emulator/qtools/trace_reader.cpp: In function 'char* ExtractDexPathFromMmap(const char*)':
development/emulator/qtools/trace_reader.cpp:1012: error: invalid conversion from 'const char*' to 'char*'
development/emulator/qtools/trace_reader.cpp:1015: error: invalid conversion from 'const char*' to 'char*'
make: *** [out/host/linux-x86/obj/EXECUTABLES/bb2sym_intermediates/trace_reader.o] error 1

檢查gcc的版本

$ ls -al /usr/bin/gcc
$ gcc --version

若是為4.4.0以上的版本, 則因為該版本在編譯時的語法要求較高, 導致編譯失敗, 解決方法是降gcc的版本

$ sudo apt-get install gcc-4.3
$ sudo apt-get install g++-4.3
$ sudo ln -f /usr/bin/gcc-4.3 /usr/bin/gcc
$ sudo ln -f /usr/bin/g++-4.3 /usr/bin/g++

也可以透過update-alternatives工具做切換(symbolic links)
安裝各版本的gcc

$ sudo apt-get install gcc-4.1 gcc-4.3 gcc-4.4

使用update-alternatives

Usage: update-alternatives [<option> ...] <command>
Commands:
  --install <link> <name> <path> <priority>
  <link> is the symlink pointing to /etc/alternatives/<name>.
    (e.g. /usr/bin/pager)
  <name> is the master name for this link group.
    (e.g. pager)
  <path> is the location of one of the alternative target files.
    (e.g. /usr/bin/less)
  <priority> is an integer; options with higher numbers have higher priority in
    automatic mode.

建立symbolic links(update-alternatives --install <link> <name> <path> <priority>)

$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.1 1
$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.3 2
$ sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.4 3

切換gcc版本

$ sudo update-alternatives --config gcc

顯示結果

Selection    Path              Priority   Status
------------------------------------------------------------
  0            /usr/bin/gcc-4.1   1         auto mode
  1            /usr/bin/gcc-4.1   1         manual mode
* 2            /usr/bin/gcc-4.3   2         manual mode
  3            /usr/bin/gcc-4.4   3         manual mode

Press enter to keep the current choice[*], or type selection number: 

reference: [Android開發]Android開發環境建立-gcc的問題


編譯Eclair/Froyo:

Exception in thread "main" java.lang.NoClassDefFoundError: javax/tools/StandardJavaFileManager
at java.lang.ClassLoader.defineClass2(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:719)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:160)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:254)
at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at com.sun.tools.javac.main.Main.compile(Main.java:269)
at com.sun.tools.javac.Main.compile(Main.java:87)
at util.build.JavacBuildStep.build(JavacBuildStep.java:69)
at util.build.BuildDalvikSuite.handleTests(BuildDalvikSuite.java:498)
at util.build.BuildDalvikSuite.compose(BuildDalvikSuite.java:170)
at util.build.BuildDalvikSuite.main(BuildDalvikSuite.java:136)
make: *** [out/host/linux-x86/obj/EXECUTABLES/vm-tests_intermediates/tests] Error 1

編輯/etc/security/limits.conf, 註解掉

#* hard nofile 4096

新增

* soft nofile 8192
* hard nofile 8192

target Java: Browser (out/target/common/obj/APPS/Browser_intermediates/classes)
packages/apps/Browser/src/com/android/browser/DownloadTouchIcon.java:81: cannot find symbol
symbol : method getPreferredHttpHost(android.content.Context,java.lang.String)
location: class android.net.Proxy
HttpHost httpHost = Proxy.getPreferredHttpHost(mContext, url);
^
packages/apps/Browser/src/com/android/browser/FetchUrlMimeType.java:73: cannot find symbol
symbol : method getPreferredHttpHost(com.android.browser.BrowserActivity,java.lang.String)
location: class android.net.Proxy
HttpHost httpHost = Proxy.getPreferredHttpHost(mActivity, uri);
^
Note: Some input files use or override a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.
2 errors
make: *** [out/target/common/obj/APPS/Browser_intermediates/classes-full-debug.jar] Error 41

之前提到在Ubuntu使用sun-java-sdk, 若是在java6的環境編譯時就會出現以上問題, 原因大概是@override annotation的關係, 可是JDK 1.6當然有支援annotation, 這部份未來再補充

reference: Android4SAM FAQ

[Tips] 常用到的Android SDK Commands

create sdcard

$ mksdcard [SDCARD_SIZE]M [SDCARD_NAME]

create emulator

$ android create avd --target [TARGET_VER] --name [TARGET_NAME] --sdcard [SDCARD_NAME]

list emulator

$ android list avd

start emulator

$ emulator -avd [TARGET_NAME] -sdcard /path/to/sdcard

install apk via Internet

$ adb export ADBHOST=[MY_ANDROID_IP]
$ /path/to/sdk/tools/adb kill-server
$ adb install [MY_APP.apk]

tcpdump

$ adb shell tcpdump -i any -p -s 0 -w /sdcard/capture.pcap
"-i any": listen on any network interface
"-p": disable promiscuous mode (doesn't work anyway)
"-s 0": capture the entire packet
"-w": write packets to a file (rather than printing to stdout)

[Tips] 在Ubuntu使用sun-java-sdk

/** update @ 2011-09-22 **/
由於jaunty archive已經找不到sun的JDK package,所以現在只能去oracle官網下載:
* jdk-1.5
* jdk-6


一開始在寫Android的應用程式時,都是使用openjdk做為java sdk,
可是總是有說不出的怪,偶爾也會踢到不知名的鐵板,

因此換掉openjdk就是必要的動作啦...

新增repository

// jdk-1.5
$ sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu/ jaunty multiverse"
$ sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu/ jaunty-updates multiverse"

// jdk-1.6
$ sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner"

更新repository內容

$ sudo apt-get update

安裝sun-java-sdk

// jdk-1.5
$ sudo apt-get install sun-java5-jdk sun-java5-plugin

// jdk-1.6
$ sudo apt-get install sun-java6-jdk sun-java6-plugin

更新jre/sdk

// 手動更改
$ update-alternatives --config java
$ update-alternatives --config javac

// 指定更改為jdk-1.6
$ sudo update-java-alternatives -s java-6-sun

那到底是要選擇哪個版本呢? It depends...

比如說在編譯Android source code時,如果使用jdk-1.6的版本,就會遇到以下錯誤訊息,改成jdk-1.5就沒問題了

Checking build tools versions...
********************************************************
You are attempting to build with the incorrect version
of java.

Your version is: java version "1.6.0_22".
The correct version is: 1.5.

Please follow the machine setup instructions at
http://source.android.com/download
********************************************************
build/core/main.mk:117: *** stop. Stop.

但是如果要使用Android的Draw 9-patch工具時,如果使用jdk-1.5的版本,就會遇到以下錯誤訊息,改成jdk-1.6就沒問題了

/usr/share/themes/Ambiance/gtk-2.0/gtkrc:71: Failed to parse property value " GTK_SHADOW_NONE " for `GtkToolbar::shadow-type'
/usr/share/themes/Ambiance/gtk-2.0/gtkrc:72: Failed to parse property value " GTK_SHADOW_NONE " for `GtkMenuBar::shadow-type'
/usr/share/themes/Ambiance/gtk-2.0/gtkrc:75: error: lexical error or unexpected token, expected valid token

reference:
* Oracle Sun JDK vs OpenJDK
* How to install Sun Java 1.5 on Ubuntu 10.04
* JAVA音樂播放器YOYOPlayer1.1發佈

[Tips] Control Your Android Device Remotely Using Mouse and Keyboard

Download: androidscreencast
Launch: $ javaws <jnlp file>

Limitations: slow refresh rate (about 4-5 fps)
Google Code Project here

[Android] 開機自動啟動的service

程式架構

|-- AndroidManifext.xml     // --> 設定receiver, service, uses-permission
`-- src
    |-- DoService.java      // --> 實際執行的service
    `-- HelloReceiver.java  // --> 接受啟動訊息, 再啟動DoService

直接看扣,
HelloReceiver.java

package hello.receiver;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;

public class HelloReceiver extends BroadcastReceiver {
  @Override
    public void onReceive(Context context, Intent intent) {
      context.startService(new Intent(context, DoService.class)); 
    }   
}

DoService.java

package hello.receiver;

import android.app.Service;
import android.content.Intent;
import android.os.Handler;
import android.os.IBinder;

public class DoService extends Service {
  private Handler handler = new Handler();
  private int delay_interval = 1000 * 60; // do every 60 seconds

  @Override
    public void onStart(Intent intent, int startId) {
      handler.postDelayed(doUpdate, delay_interval);
      super.onStart(intent, startId);
    }

  public Runnable doUpdate = new Runnable() {
    public void run() {
      handler.postDelayed(this, delay_interval);
    }
  };

  @Override
    public IBinder onBind(Intent arg0) {
      return null;
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
  package="hello.receiver"
  android:versionCode="1"
  android:versionName="1.0">
  <application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name=".HelloReceiver" android:label="@string/app_name">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
    <receiver android:name="HelloReceiver">
      <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
        <category android:name="android.intent.category.HOME" />
      </intent-filter>
    </receiver>
    <service android:name=".myThread">
      <intent-filter>
        <action android:name="hello.receiver.DoService" />
        <category android:name="android.intent.category.DEFAULT" />
      </intent-filter>
    </service>
   </application>
   <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"></uses-permission>
</manifest>

reference:
* Running code on phone boot
* Starting an Android service after boot

[轉貼] [Android] JAR Library: Export and Import

原文標題: [Android] JAR Library: Export and Import
原文作者: web_surf@163.com
發表日期: 2010-06-18 09:42
原文來源: https://bbs.et8.net/bbs/showthread.php?t=616987

1.Export Library

* Prepare source code
- Create an Android project
- Create source code, and fix all bug
- Remove res/*
- Remove unused source files
- Edit AndroidManifest.xml to remove the statements that referes to resource, such as android:icon="@drwable/icon", android:label="@string/app_name"

* Export library
- On Package Explorer Panel of Eclipse, right-click the project, and select Export
- Select Jave -> JAR file, then press "Next". At this time a dialog pops up.
- On the right panel of "Select the resources to export:" group, unselect all items (such as .classpath, .project, AndroidManifest.xlm, default.properties), then press "Next"
Press "Next"
Press "Finish"

Then the library is created.
(Reference: Eclipse export jar files http://hi.baidu.com/etrigger/blog/item/e1fed134468b2fb2d0a2d3ad.html)
* xxx

2.Import Library

You can use a third party JAR in your application by adding it to your Eclipse project as follows:
- In the Package Explorer panel, right-click on your project and select Properties.
- Select Java Build Path, then the tab Libraries.
- Press the Add External JARs... button and select the JAR file

Alternatively, if you want to include third party JARs with your package, create a new directory for them within your project and select Add Library... instead.
It is not necessary to put external JARs in the assets folder.
(Reference: http://code.google.com/intl/zh-CN/android/kb/commontasks.html)

簡單的作法是靠Eclipse的Project->Export, 僅選取src的部份, 匯出即可
Import還是靠Eclipse的Project->Properties->Java Build Path->Libraries->Add External JARs即可