Android访问Health Connect数据时出现资源未调用close错误求助

问题代码 #

suspend fun readStepsByTimeRange(
    healthConnectClient: HealthConnectClient,
    startTime: Instant,
    endTime: Instant
) {
    val response =
        healthConnectClient.readRecords(
            ReadRecordsRequest(
                StepsRecord::class,
                timeRangeFilter = TimeRangeFilter.between(startTime, endTime)
            )
        )
    for (stepRecord in response.records) {
        // do stuff
    }
}

崩溃堆栈信息 #

D/StrictMode: StrictMode policy violation: android.os.strictmode.LeakedClosableViolation: A resource was acquired at attached stack trace but never released. See java.io.Closeable for information on avoiding resource leaks. Callsite: close
        at android.os.StrictMode$AndroidCloseGuardReporter.report(StrictMode.java:1992)
        at dalvik.system.CloseGuard.warnIfOpen(CloseGuard.java:338)
        at sun.nio.fs.UnixSecureDirectoryStream.finalize(UnixSecureDirectoryStream.java:580)
        at java.lang.Daemons$FinalizerDaemon.doFinalize(Daemons.java:319)
        at java.lang.Daemons$FinalizerDaemon.runInternal(Daemons.java:306)
        at java.lang.Daemons$Daemon.run(Daemons.java:140)
        at java.lang.Thread.run(Thread.java:1012)

原因分析 #

这个错误是Android StrictMode检测到可关闭资源未被正确释放导致的，具体原因：

• ReadRecordsResponse实现了Closeable接口，它持有Health Connect底层的文件/目录流资源，当前代码使用完response后未调用close()方法释放资源，造成资源泄漏。
• 从堆栈信息可见，未关闭的是UnixSecureDirectoryStream，这是Health Connect存储数据依赖的底层资源，只要ReadRecordsResponse不关闭，这些资源会一直被持有，触发StrictMode的违规检测并导致崩溃。

修复方案 #

使用Kotlin的use扩展函数自动关闭ReadRecordsResponse，该函数会在代码块执行完成后（无论是否抛出异常）自动调用close()：

suspend fun readStepsByTimeRange(
    healthConnectClient: HealthConnectClient,
    startTime: Instant,
    endTime: Instant
) {
    healthConnectClient.readRecords(
        ReadRecordsRequest(
            StepsRecord::class,
            timeRangeFilter = TimeRangeFilter.between(startTime, endTime)
        )
    ).use { response ->
        for (stepRecord in response.records) {
            // do stuff
        }
    }
}

内容的提问来源于stack exchange，提问作者Paul Jablonski