https://loizenai.com Programming Tutorial
1619444591
https://grokonez.com/spring-framework/spring-batch/configure-spring-batch-step-restart
How to configure Spring Batch Step for restart
In How to use Spring Batch Restartable Function, we had discussed about how to restart a Job. Today, JavaSampleApproach will guide you how to use additional configuration for step in case restart a Batch Job.
Related articles:
<step id="step3">
<tasklet start-limit="${limitstart}" ref="taskletStep3"/>
</step>
<step id="step3">
<tasklet start-limit="${limitstart}" ref="taskletStep3"/>
</step>
More at:
https://grokonez.com/spring-framework/spring-batch/configure-spring-batch-step-restart
How to configure Spring Batch Step for restart
#springbatch #springboot #restart
1621240500
Batch processing is dealing with a large amount of data; it actually is a method of running high-volume, repetitive data jobs and each job does a specific task without user interaction. This kind of processing started from the beginning of computation and still continues and perhaps new methods, algorithms, and tools are still being introduced. The entry point of Batch Processing Systems is offline data that gathered in any type like CSV, RDBMS, or well-formed JSON or XML files, after processing data and doing the specified process on every record of data, the desired output is generated.
#java #tutorial #big data #spring #spring boot #apache spark #spring batch #spring batch tutorial
1652543820
Background Fetch is a very simple plugin which attempts to awaken an app in the background about every 15 minutes, providing a short period of background running-time. This plugin will execute your provided callbackFn
whenever a background-fetch event occurs.
There is no way to increase the rate which a fetch-event occurs and this plugin sets the rate to the most frequent possible — you will never receive an event faster than 15 minutes. The operating-system will automatically throttle the rate the background-fetch events occur based upon usage patterns. Eg: if user hasn't turned on their phone for a long period of time, fetch events will occur less frequently or if an iOS user disables background refresh they may not happen at all.
:new: Background Fetch now provides a scheduleTask
method for scheduling arbitrary "one-shot" or periodic tasks.
scheduleTask
seems only to fire when the device is plugged into power.stopOnTerminate: false
for iOS.@config enableHeadless
)⚠️ If you have a previous version of react-native-background-fetch < 2.7.0
installed into react-native >= 0.60
, you should first unlink
your previous version as react-native link
is no longer required.
$ react-native unlink react-native-background-fetch
yarn
$ yarn add react-native-background-fetch
npm
$ npm install --save react-native-background-fetch
react-native >= 0.60
react-native >= 0.60
ℹ️ This repo contains its own Example App. See /example
import React from 'react';
import {
SafeAreaView,
StyleSheet,
ScrollView,
View,
Text,
FlatList,
StatusBar,
} from 'react-native';
import {
Header,
Colors
} from 'react-native/Libraries/NewAppScreen';
import BackgroundFetch from "react-native-background-fetch";
class App extends React.Component {
constructor(props) {
super(props);
this.state = {
events: []
};
}
componentDidMount() {
// Initialize BackgroundFetch ONLY ONCE when component mounts.
this.initBackgroundFetch();
}
async initBackgroundFetch() {
// BackgroundFetch event handler.
const onEvent = async (taskId) => {
console.log('[BackgroundFetch] task: ', taskId);
// Do your background work...
await this.addEvent(taskId);
// IMPORTANT: You must signal to the OS that your task is complete.
BackgroundFetch.finish(taskId);
}
// Timeout callback is executed when your Task has exceeded its allowed running-time.
// You must stop what you're doing immediately BackgroundFetch.finish(taskId)
const onTimeout = async (taskId) => {
console.warn('[BackgroundFetch] TIMEOUT task: ', taskId);
BackgroundFetch.finish(taskId);
}
// Initialize BackgroundFetch only once when component mounts.
let status = await BackgroundFetch.configure({minimumFetchInterval: 15}, onEvent, onTimeout);
console.log('[BackgroundFetch] configure status: ', status);
}
// Add a BackgroundFetch event to <FlatList>
addEvent(taskId) {
// Simulate a possibly long-running asynchronous task with a Promise.
return new Promise((resolve, reject) => {
this.setState(state => ({
events: [...state.events, {
taskId: taskId,
timestamp: (new Date()).toString()
}]
}));
resolve();
});
}
render() {
return (
<>
<StatusBar barStyle="dark-content" />
<SafeAreaView>
<ScrollView
contentInsetAdjustmentBehavior="automatic"
style={styles.scrollView}>
<Header />
<View style={styles.body}>
<View style={styles.sectionContainer}>
<Text style={styles.sectionTitle}>BackgroundFetch Demo</Text>
</View>
</View>
</ScrollView>
<View style={styles.sectionContainer}>
<FlatList
data={this.state.events}
renderItem={({item}) => (<Text>[{item.taskId}]: {item.timestamp}</Text>)}
keyExtractor={item => item.timestamp}
/>
</View>
</SafeAreaView>
</>
);
}
}
const styles = StyleSheet.create({
scrollView: {
backgroundColor: Colors.lighter,
},
body: {
backgroundColor: Colors.white,
},
sectionContainer: {
marginTop: 32,
paddingHorizontal: 24,
},
sectionTitle: {
fontSize: 24,
fontWeight: '600',
color: Colors.black,
},
sectionDescription: {
marginTop: 8,
fontSize: 18,
fontWeight: '400',
color: Colors.dark,
},
});
export default App;
In addition to the default background-fetch task defined by BackgroundFetch.configure
, you may also execute your own arbitrary "oneshot" or periodic tasks (iOS requires additional Setup Instructions). However, all events will be fired into the Callback provided to BackgroundFetch#configure
:
scheduleTask
on iOS seems only to run when the device is plugged into power.scheduleTask
on iOS are designed for low-priority tasks, such as purging cache files — they tend to be unreliable for mission-critical tasks. scheduleTask
will never run as frequently as you want.fetch
event is much more reliable and fires far more often.scheduleTask
on iOS stop when the user terminates the app. There is no such thing as stopOnTerminate: false
for iOS.// Step 1: Configure BackgroundFetch as usual.
let status = await BackgroundFetch.configure({
minimumFetchInterval: 15
}, async (taskId) => { // <-- Event callback
// This is the fetch-event callback.
console.log("[BackgroundFetch] taskId: ", taskId);
// Use a switch statement to route task-handling.
switch (taskId) {
case 'com.foo.customtask':
print("Received custom task");
break;
default:
print("Default fetch task");
}
// Finish, providing received taskId.
BackgroundFetch.finish(taskId);
}, async (taskId) => { // <-- Task timeout callback
// This task has exceeded its allowed running-time.
// You must stop what you're doing and immediately .finish(taskId)
BackgroundFetch.finish(taskId);
});
// Step 2: Schedule a custom "oneshot" task "com.foo.customtask" to execute 5000ms from now.
BackgroundFetch.scheduleTask({
taskId: "com.foo.customtask",
forceAlarmManager: true,
delay: 5000 // <-- milliseconds
});
API Documentation
@param {Integer} minimumFetchInterval [15]
The minimum interval in minutes to execute background fetch events. Defaults to 15
minutes. Note: Background-fetch events will never occur at a frequency higher than every 15 minutes. Apple uses a secret algorithm to adjust the frequency of fetch events, presumably based upon usage patterns of the app. Fetch events can occur less often than your configured minimumFetchInterval
.
@param {Integer} delay (milliseconds)
ℹ️ Valid only for BackgroundFetch.scheduleTask
. The minimum number of milliseconds in future that task should execute.
@param {Boolean} periodic [false]
ℹ️ Valid only for BackgroundFetch.scheduleTask
. Defaults to false
. Set true to execute the task repeatedly. When false
, the task will execute just once.
@config {Boolean} stopOnTerminate [true]
Set false
to continue background-fetch events after user terminates the app. Default to true
.
@config {Boolean} startOnBoot [false]
Set true
to initiate background-fetch events when the device is rebooted. Defaults to false
.
❗ NOTE: startOnBoot
requires stopOnTerminate: false
.
@config {Boolean} forceAlarmManager [false]
By default, the plugin will use Android's JobScheduler
when possible. The JobScheduler
API prioritizes for battery-life, throttling task-execution based upon device usage and battery level.
Configuring forceAlarmManager: true
will bypass JobScheduler
to use Android's older AlarmManager
API, resulting in more accurate task-execution at the cost of higher battery usage.
let status = await BackgroundFetch.configure({
minimumFetchInterval: 15,
forceAlarmManager: true
}, async (taskId) => { // <-- Event callback
console.log("[BackgroundFetch] taskId: ", taskId);
BackgroundFetch.finish(taskId);
}, async (taskId) => { // <-- Task timeout callback
// This task has exceeded its allowed running-time.
// You must stop what you're doing and immediately .finish(taskId)
BackgroundFetch.finish(taskId);
});
.
.
.
// And with with #scheduleTask
BackgroundFetch.scheduleTask({
taskId: 'com.foo.customtask',
delay: 5000, // milliseconds
forceAlarmManager: true,
periodic: false
});
@config {Boolean} enableHeadless [false]
Set true
to enable React Native's Headless JS mechanism, for handling fetch events after app termination.
index.js
(MUST BE IN index.js
):import BackgroundFetch from "react-native-background-fetch";
let MyHeadlessTask = async (event) => {
// Get task id from event {}:
let taskId = event.taskId;
let isTimeout = event.timeout; // <-- true when your background-time has expired.
if (isTimeout) {
// This task has exceeded its allowed running-time.
// You must stop what you're doing immediately finish(taskId)
console.log('[BackgroundFetch] Headless TIMEOUT:', taskId);
BackgroundFetch.finish(taskId);
return;
}
console.log('[BackgroundFetch HeadlessTask] start: ', taskId);
// Perform an example HTTP request.
// Important: await asychronous tasks when using HeadlessJS.
let response = await fetch('https://reactnative.dev/movies.json');
let responseJson = await response.json();
console.log('[BackgroundFetch HeadlessTask] response: ', responseJson);
// Required: Signal to native code that your task is complete.
// If you don't do this, your app could be terminated and/or assigned
// battery-blame for consuming too much time in background.
BackgroundFetch.finish(taskId);
}
// Register your BackgroundFetch HeadlessTask
BackgroundFetch.registerHeadlessTask(MyHeadlessTask);
@config {integer} requiredNetworkType [BackgroundFetch.NETWORK_TYPE_NONE]
Set basic description of the kind of network your job requires.
If your job doesn't need a network connection, you don't need to use this option as the default value is BackgroundFetch.NETWORK_TYPE_NONE
.
NetworkType | Description |
---|---|
BackgroundFetch.NETWORK_TYPE_NONE | This job doesn't care about network constraints, either any or none. |
BackgroundFetch.NETWORK_TYPE_ANY | This job requires network connectivity. |
BackgroundFetch.NETWORK_TYPE_CELLULAR | This job requires network connectivity that is a cellular network. |
BackgroundFetch.NETWORK_TYPE_UNMETERED | This job requires network connectivity that is unmetered. Most WiFi networks are unmetered, as in "you can upload as much as you like". |
BackgroundFetch.NETWORK_TYPE_NOT_ROAMING | This job requires network connectivity that is not roaming (being outside the country of origin) |
@config {Boolean} requiresBatteryNotLow [false]
Specify that to run this job, the device's battery level must not be low.
This defaults to false. If true, the job will only run when the battery level is not low, which is generally the point where the user is given a "low battery" warning.
@config {Boolean} requiresStorageNotLow [false]
Specify that to run this job, the device's available storage must not be low.
This defaults to false. If true, the job will only run when the device is not in a low storage state, which is generally the point where the user is given a "low storage" warning.
@config {Boolean} requiresCharging [false]
Specify that to run this job, the device must be charging (or be a non-battery-powered device connected to permanent power, such as Android TV devices). This defaults to false.
@config {Boolean} requiresDeviceIdle [false]
When set true, ensure that this job will not run if the device is in active use.
The default state is false: that is, the for the job to be runnable even when someone is interacting with the device.
This state is a loose definition provided by the system. In general, it means that the device is not currently being used interactively, and has not been in use for some time. As such, it is a good time to perform resource heavy jobs. Bear in mind that battery usage will still be attributed to your application, and shown to the user in battery stats.
Method Name | Arguments | Returns | Notes |
---|---|---|---|
configure | {FetchConfig} , callbackFn , timeoutFn | Promise<BackgroundFetchStatus> | Configures the plugin's callbackFn and timeoutFn . This callback will fire each time a background-fetch event occurs in addition to events from #scheduleTask . The timeoutFn will be called when the OS reports your task is nearing the end of its allowed background-time. |
scheduleTask | {TaskConfig} | Promise<boolean> | Executes a custom task. The task will be executed in the same Callback function provided to #configure . |
status | callbackFn | Promise<BackgroundFetchStatus> | Your callback will be executed with the current status (Integer) 0: Restricted , 1: Denied , 2: Available . These constants are defined as BackgroundFetch.STATUS_RESTRICTED , BackgroundFetch.STATUS_DENIED , BackgroundFetch.STATUS_AVAILABLE (NOTE: Android will always return STATUS_AVAILABLE ) |
finish | String taskId | Void | You MUST call this method in your callbackFn provided to #configure in order to signal to the OS that your task is complete. iOS provides only 30s of background-time for a fetch-event -- if you exceed this 30s, iOS will kill your app. |
start | none | Promise<BackgroundFetchStatus> | Start the background-fetch API. Your callbackFn provided to #configure will be executed each time a background-fetch event occurs. NOTE the #configure method automatically calls #start . You do not have to call this method after you #configure the plugin |
stop | [taskId:String] | Promise<boolean> | Stop the background-fetch API and all #scheduleTask from firing events. Your callbackFn provided to #configure will no longer be executed. If you provide an optional taskId , only that #scheduleTask will be stopped. |
BGTaskScheduler
API for iOS 13+[||]
button to initiate a Breakpoint.(lldb)
, paste the following command (Note: use cursor up/down keys to cycle through previously run commands):e -l objc -- (void)[[BGTaskScheduler sharedScheduler] _simulateLaunchForTaskWithIdentifier:@"com.transistorsoft.fetch"]
[ > ]
button to continue. The task will execute and the Callback function provided to BackgroundFetch.configure
will receive the event.BGTaskScheduler
api supports simulated task-timeout events. To simulate a task-timeout, your fetchCallback
must not call BackgroundFetch.finish(taskId)
:let status = await BackgroundFetch.configure({
minimumFetchInterval: 15
}, async (taskId) => { // <-- Event callback.
// This is the task callback.
console.log("[BackgroundFetch] taskId", taskId);
//BackgroundFetch.finish(taskId); // <-- Disable .finish(taskId) when simulating an iOS task timeout
}, async (taskId) => { // <-- Event timeout callback
// This task has exceeded its allowed running-time.
// You must stop what you're doing and immediately .finish(taskId)
print("[BackgroundFetch] TIMEOUT taskId:", taskId);
BackgroundFetch.finish(taskId);
});
e -l objc -- (void)[[BGTaskScheduler sharedScheduler] _simulateExpirationForTaskWithIdentifier:@"com.transistorsoft.fetch"]
BackgroundFetch
APIDebug->Simulate Background Fetch
$ adb logcat
:$ adb logcat *:S ReactNative:V ReactNativeJS:V TSBackgroundFetch:V
21+
:$ adb shell cmd jobscheduler run -f <your.application.id> 999
<21
, simulate a "Headless JS" event with (insert <your.application.id>)$ adb shell am broadcast -a <your.application.id>.event.BACKGROUND_FETCH
Download Details:
Author: transistorsoft
Source Code: https://github.com/transistorsoft/react-native-background-fetch
License: MIT license
1624438560
The concept of the scope of a bean in spring enables us to focus on business logic without having to worry about data inconsistency.
The lifespan of beans in a spring application are defined with respect to the application context(@Singleton), thread (@Prototype), or incase of web-aware applications http session (@Session), http request (@Request) or servlet lifecycle (@ApplicationScope), webSocket session.
In other words, a bean annotated with @Singelton will be created once when the container is initialized (Application is started) and is destroyed when the container is terminated (Application is shut down).
Similarly, a bean annotated with @prototype is created every time there is a new request for the bean. Bean annotated with @Session is created once per session and a bean annotated with @Request is created for every http request.
As can be seen, we have a large bevy of bean scopes to choose from for every custom application need. We have specific scopes pertaining to web applications, we have scopes pertaining to application contexts.
So far so good. But in the case of a spring batch job, the above-mentioned scopes can be used only up to a certain extent. As a SpringBatch Job comprises of steps thus it is only natural and practical to define beans with respect to a step in addition to be the above-mentioned scopes.
Luckily for us, Spring defines two more scopes namely step scope and job scope that help us in defining beans whose lifecycles are tied to the lifecycle of a job and a step respectively.
#scopes #springbatch #java #step scoped beans in a spring batch job #spring batch job #spring
1641511860
Spring Fu is an incubator for JaFu (Java DSL) and KoFu (Kotlin DSL) designed to configure Spring Boot explicitly with code in a declarative way with great discoverability thanks to auto-complete. It provides fast startup (40% faster than regular auto-configuration on a minimal Spring MVC app), low memory consumption and is a good fit with GraalVM native thanks to its (almost) reflection-less approach.
Spring Fu is not intended to be used in production yet, but rather to incubate and get feedback and contributions from the community in order to hopefully reach a point where it can be integrated as part of Spring Framework and Spring Boot.
In addition to the whole Spring and Reactor teams, special credits to:
1620720872
As an extension of the Spring Framework, Spring Boot is widely used to make development on Spring faster, more efficient and convenient. In this article, we will look at some of the parameters were using Spring Boot can drastically reduce the time and effort required in application development.
#full stack development #spring #spring and spring boot #spring boot