安卓连接数据库[练习]

Android入门案例(二)——JDBC连接MySql数据库实现登录

Android入门案例(一)——简单登录

1 导入jar包

复制到demo\app\libs目录下，在as中找到新增的jar包，右键Add as libs

Error:Execution failed for task ':app:preDebugAndroidTestBuild'

build->rebuild 未解决，新出现了问题err解决参考

Error:com.android.builder.dexing.DexArchiveBuilderException

Cause: invalid opcode ba (invokedynamic requires --min-sdk-version >= 26)

解决参考1 参考2

Error:Execution failed for task ':app:preDebugAndroidTestBuild'.

> Conflict with dependency 'com.android.support:support-annotations' in project ':app'. Resolved versions for app (26.1.0) and test app (27.1.1) differ. See https://d.android.com/r/tools/test-apk-dependency-conflicts.html for details.

解决参考

2 添加网络访问权限

g

3 连接数据库

pic

java.lang.NoClassDefFoundError: com/google/protobuf/ProtocolMessageEnum

参考

The type com.google.protobuf.GeneratedMessageV3$Builder cannot be resolved

参考

Error:com.android.dx.cf.code.SimException: default or static interface method used without --min-sdk-version >= 24

参考

Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'.

> com.android.builder.dexing.DexArchiveMergerException: com.android.tools.r8.errors.CompilationError: Program type already present: com.google.protobuf.AbstractMessageLite

参考

Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'.

> com.android.builder.dexing.DexArchiveMergerException: com.android.tools.r8.errors.CompilationError: Program type already present: com.google.protobuf.AbstractMessageLite

android.content.ActivityNotFoundException: Unable to find explicit activity class {com.asp.wattmelon.demo/com.asp.wattmelon.demo.infoActivity}; have you declared this activity in your AndroidManifest.xml?