@ohos.faultLogger (FaultLogger)

The faultLogger APIs can be used to query fault logs of an application cached on the system. The APIs use the application bundle name and the UID allocated by the system as the unique key value.

The number of application fault logs stored in the system is limited by the system log pressure. You are advised to use @ohos.hiviewdfx.hiAppEvent to subscribe to fault events such as APP_CRASH and APP_FREEZE.

NOTE

The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.

The APIs of this module are no longer maintained since API version 18. You are advised to use @ohos.hiviewdfx.hiAppEvent to subscribe to the APP_CRASH and APP_FREEZE events in later versions.

For details about how to use HiAppEvent to subscribe to the APP_CRASH event, see Migrating Crash Events from the FaultLogger API.

For details about how to use HiAppEvent to subscribe to the APP_FREEZE event, see Migrating Application Freeze Events from the Faultlogger API.

Modules to Import

import { FaultLogger } from '@kit.PerformanceAnalysisKit';

FaultType

Enumerates the fault types.

System capability: SystemCapability.HiviewDFX.Hiview.FaultLogger

Name	Value	Description
NO_SPECIFIC	0	No specific fault type.
CPP_CRASH	2	C++ program crash.
JS_CRASH	3	JS program crash.
APP_FREEZE	4	Application freezing.

FaultLogInfo

Defines the data structure of the fault log information.

System capability: SystemCapability.HiviewDFX.Hiview.FaultLogger

Name	Type	Read-Only	Optional	Description
pid	number	No	No	Process ID of the faulty process.
uid	number	No	No	User ID of the faulty process.
type	FaultType	No	No	Fault type.
timestamp	number	No	No	Millisecond-level timestamp when the log was generated.
reason	string	No	No	Reason for the fault.
module	string	No	No	Module on which the fault occurred.
summary	string	No	No	Summary of the fault.
fullLog	string	No	No	Full log text.

FaultLogger.query⁹⁺

query(faultType: FaultType, callback: AsyncCallback<Array<FaultLogInfo>>) : void

Obtains the fault information about the current application. This API uses an asynchronous callback to return the fault information array obtained, which contains a maximum of 10 pieces of fault information.

System capability: SystemCapability.HiviewDFX.Hiview.FaultLogger

Parameters

Name	Type	Mandatory	Description
faultType	FaultType	Yes	Fault type.
callback	AsyncCallback<Array<FaultLogInfo>>	Yes	Callback used to return the fault information array. value is the fault information array obtained. If value is undefined, an exception occurs during the information retrieval. In this case, an error string will be returned.

Error codes

For details about the error codes, see FaultLogger Error Codes.

ID	Error Message
401	The parameter check failed, Parameter type error.
801	The specified SystemCapability name was not found.
10600001	The service is not started or is faulty.

Example

import { FaultLogger } from '@kit.PerformanceAnalysisKit';
import { BusinessError } from '@kit.BasicServicesKit';

function queryFaultLogCallback(error: BusinessError, value: Array<FaultLogger.FaultLogInfo>) {
    if (error) {
        console.error(`error code:${error.code}, error msg:${error.message}`);
    } else {
        console.info("value length is " + value.length);
        let len: number = value.length;
        for (let i = 0; i < len; i++) {
            console.info(`log: ${i}`);
            console.info(`Log pid: ${value[i].pid}`);
            console.info(`Log uid: ${value[i].uid}`);
            console.info(`Log type: ${value[i].type}`);
            console.info(`Log timestamp: ${value[i].timestamp}`);
            console.info(`Log reason: ${value[i].reason}`);
            console.info(`Log module: ${value[i].module}`);
            console.info(`Log summary: ${value[i].summary}`);
            console.info(`Log text: ${value[i].fullLog}`);
        }
    }
}
try {
    FaultLogger.query(FaultLogger.FaultType.JS_CRASH, queryFaultLogCallback);
} catch (err) {
    console.error(`code: ${(err as BusinessError).code}, message: ${(err as BusinessError).message}`);
}

FaultLogger.query⁹⁺

query(faultType: FaultType) : Promise<Array<FaultLogInfo>>

Obtains the fault information about the current application. This API uses a promise to return the fault information array obtained, which contains a maximum of 10 pieces of fault information.

System capability: SystemCapability.HiviewDFX.Hiview.FaultLogger

Parameters

Name	Type	Mandatory	Description
faultType	FaultType	Yes	Fault type.

Return value

Type	Description
Promise<Array<FaultLogInfo>>	Promise used to return the fault information array. You can obtain the fault information instance in its then() method or use await. value is the fault information array obtained. If value is undefined, an exception occurs during the information retrieval.

Error codes

For details about the error codes, see FaultLogger Error Codes.

ID	Error Message
401	The parameter check failed, Parameter type error.
801	The specified SystemCapability name was not found.
10600001	The service is not started or is faulty.

Example

import { FaultLogger } from '@kit.PerformanceAnalysisKit';
import { BusinessError } from '@kit.BasicServicesKit';

async function getLog() {
  try {
    let value: Array<FaultLogger.FaultLogInfo> = await FaultLogger.query(FaultLogger.FaultType.JS_CRASH);
    if (value) {
      console.info(`value length: ${value.length}`);
      let len: number = value.length;
      for (let i = 0; i < len; i++) {
        console.info(`log: ${i}`);
        console.info(`Log pid: ${value[i].pid}`);
        console.info(`Log uid: ${value[i].uid}`);
        console.info(`Log type: ${value[i].type}`);
        console.info(`Log timestamp: ${value[i].timestamp}`);
        console.info(`Log reason: ${value[i].reason}`);
        console.info(`Log module: ${value[i].module}`);
        console.info(`Log summary: ${value[i].summary}`);
        console.info(`Log text: ${value[i].fullLog}`);
      }
    }
  } catch (err) {
    console.error(`code: ${(err as BusinessError).code}, message: ${(err as BusinessError).message}`);
  }
}

FaultLogger.querySelfFaultLog^(deprecated)

querySelfFaultLog(faultType: FaultType, callback: AsyncCallback<Array<FaultLogInfo>>) : void

NOTE

This API is supported since API version 8 and deprecated since API version 9. You are advised to use FaultLogger.query instead.

System capability: SystemCapability.HiviewDFX.Hiview.FaultLogger

Parameters

Name	Type	Mandatory	Description
faultType	FaultType	Yes	Fault type.
callback	AsyncCallback<Array<FaultLogInfo>>	Yes	Callback used to return the fault information array. value is the fault information array obtained. If value is undefined, an exception occurs during the information retrieval. In this case, an error string will be returned.

Example

import { FaultLogger } from '@kit.PerformanceAnalysisKit';
import { BusinessError } from '@kit.BasicServicesKit';

function queryFaultLogCallback(error: BusinessError, value: Array<FaultLogger.FaultLogInfo>) {
  if (error) {
    console.error(`error code:${error.code}, error msg:${error.message}`);
  } else {
    console.info(`value length: ${value.length}`);
    let len: number = value.length;
    for (let i = 0; i < len; i++) {
      console.info(`log: ${i}`);
      console.info(`Log pid: ${value[i].pid}`);
      console.info(`Log uid: ${value[i].uid}`);
      console.info(`Log type: ${value[i].type}`);
      console.info(`Log timestamp: ${value[i].timestamp}`);
      console.info(`Log reason: ${value[i].reason}`);
      console.info(`Log module: ${value[i].module}`);
      console.info(`Log summary: ${value[i].summary}`);
      console.info(`Log text: ${value[i].fullLog}`);
    }
  }
}
FaultLogger.querySelfFaultLog(FaultLogger.FaultType.JS_CRASH, queryFaultLogCallback);

FaultLogger.querySelfFaultLog^(deprecated)

querySelfFaultLog(faultType: FaultType) : Promise<Array<FaultLogInfo>>

NOTE

This API is supported since API version 8 and deprecated since API version 9. You are advised to use FaultLogger.query instead.

Obtains the fault information about the current application. This API uses a promise to return the fault information array obtained, which contains a maximum of 10 pieces of fault information.

System capability: SystemCapability.HiviewDFX.Hiview.FaultLogger

Parameters

Name	Type	Mandatory	Description
faultType	FaultType	Yes	Fault type.

Return value

Type	Description
Promise<Array<FaultLogInfo>>	Promise used to return the fault information array. You can obtain the fault information instance in its then() method or use await. value is the fault information array obtained. If value is undefined, an exception occurs during the information retrieval.

Example

import { FaultLogger } from '@kit.PerformanceAnalysisKit';

async function getLog() {
  let value: Array<FaultLogger.FaultLogInfo> = await FaultLogger.querySelfFaultLog(FaultLogger.FaultType.JS_CRASH);
  if (value) {
    console.info(`value length: ${value.length}`);
    let len: number = value.length;
    for (let i = 0; i < len; i++) {
      console.info(`log: ${i}`);
      console.info(`Log pid: ${value[i].pid}`);
      console.info(`Log uid: ${value[i].uid}`);
      console.info(`Log type: ${value[i].type}`);
      console.info(`Log timestamp: ${value[i].timestamp}`);
      console.info(`Log reason: ${value[i].reason}`);
      console.info(`Log module: ${value[i].module}`);
      console.info(`Log summary: ${value[i].summary}`);
      console.info(`Log text: ${value[i].fullLog}`);
    }
  }
}

@ohos.faultLogger (FaultLogger)

Modules to Import

FaultType

FaultLogInfo

FaultLogger.query9+

FaultLogger.query9+

FaultLogger.querySelfFaultLog(deprecated)

FaultLogger.querySelfFaultLog(deprecated)

FaultLogger.query⁹⁺

FaultLogger.query⁹⁺

FaultLogger.querySelfFaultLog^(deprecated)

FaultLogger.querySelfFaultLog^(deprecated)