关于jack-admin报错，网上有很多回复，出现问题大概为：
1，端口被占用
解决方法：修改端口号，文件路径 ~/.jack-server/config.properties
~/.jack-settings
prebuilts/sdk/tools/jack-admin
2， ~/.jack-server/config.properties文件权限不对，改文件需要修改为066
3，未安装cuil
我们之前代码编译都没问题，很长时间没编译之后，就出现了jack-admin报错，查看log（路径：~/.jack-server/logs），未看到报错（上述三种情况这里都可以看到报错），具体log如下：
15:33:22.966: INFO: com.android.jack.server.JackHttpServer: Starting jack server version: 1.3-a8 '1.3' (291201 fcd657165d2fd6dcf1bf4c3002c9c8f75383e815 by android-jack-team@google.com)
15:33:23.004: INFO: com.android.jack.server.JackHttpServer: Starting service connection server on /127.0.0.1:38076
15:33:23.009: INFO: com.android.jack.server.JackHttpServer: Starting admin connection on /127.0.0.1:38077
15:33:23.160: INFO: com.android.jack.server.JackHttpServer: Start timer
编译报错：
RELEASE || exit 47; prebuilts/sdk/tools/jack-admin update jack prebuilts/sdk/tools/jacks/jack-3.36.CANDIDATE.jar 3.36.CANDIDATE || exit 47; prebuilts/sdk/tools/jack-admin update jack prebuilts/sdk/tools/jacks/jack-4.7.BETA.jar 4.7.BETA || exit 47 )"
Jack server already installed in "/mnt/disk1/build/.jack-server"
Launching Jack server java -XX:MaxJavaStackTraceDepth=-1 -Djava.io.tmpdir=/tmp -Xmx8g -Dfile.encoding=UTF-8 -XX:+TieredCompilation -cp /mnt/disk1/build/.jack-server/launcher.jar com.android.jack.launcher.ServerLauncher
Jack server failed to (re)start, try 'jack-diagnose' or see Jack server log
SSL error when connecting to the Jack server. Try 'jack-diagnose'
SSL error when connecting to the Jack server. Try 'jack-diagnose'
ninja: build stopped: subcommand failed.
build/core/ninja.mk:148: recipe for target 'ninja_wrapper' failed
使用./prebuilts/sdk/tools/jack-admin dump-report得到压缩包，解压压缩包，查看report.***.txt,文件内容末端如下：
原来是java在2021/4/20的8u291更新不再支持TLS1.0和TLS1.1协议 。
解决：
sudo vi /etc/java-8-openjdk/security/java.security
删除 TLSv1, TLSv1.1, 如图所示，注释掉的问原文件内容，上面三行是我修改后的。重启一下服务器（我尝试直接source该文件无效）就可以了。
