Merge branch 'node-errorhandling' of https://github.com/pratikdas/code-examples into node-errorhandling

Author: Pratik Das

build-all.sh

@@ -100,6 +100,7 @@ fi
 
 if [[ "$MODULE" == "module6" ]]
 then
+  build_maven_module "spring-boot/spring-boot-app-info"
   build_maven_module "spring-boot/spring-boot-null-safe-annotations"
   build maven_module "aws/cdkv2"
   build_maven_module "immutables"
@@ -132,6 +133,7 @@ fi
 
 if [[ "$MODULE" == "module5" ]]
 then
+  build_maven_module "spring-boot/beginners-guide"
   build_maven_module "aws/aws-dynamodb"
   build_maven_module "spring-boot/spring-boot-testconfiguration"
   build_maven_module "aws/springcloudrds"

core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/CSV.java

@@ -0,0 +1,11 @@
+package com.reflectoring;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface CSV {
+}

core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/TestMarkerAnnotation.java

@@ -0,0 +1,16 @@
+package com.reflectoring;
+
+public class TestMarkerAnnotation {
+
+    public static void main(String[] args) {
+
+        XYZClient client = new XYZClient();
+        Class clientClass = client.getClass();
+
+        if (clientClass.isAnnotationPresent(CSV.class)){
+            System.out.println("Write client data to CSV.");
+        } else {
+            System.out.println("Write client data to Excel file.");
+        }
+    }
+}

core-java/annotation-processing/introduction-to-annotations/src/main/java/com/reflectoring/XYZClient.java

@@ -0,0 +1,6 @@
+package com.reflectoring;
+
+@CSV
+public class XYZClient {
+
+}

nodejs/middleware/app.ts

@@ -0,0 +1,118 @@
+import express, { Request, Response, NextFunction } from 'express'
+import morgan from 'morgan'
+
+const app = express()
+const port:number = 3000
+
+
+interface Product {
+
+    name: string
+    price: number
+    brand: string
+    category?: string
+  }
+
+interface ProductCreationResponse {
+    productID: string 
+    result: string
+} 
+
+
+class AppError extends Error{
+    statusCode: number;
+
+    constructor(statusCode: number, message: string) {
+      super(message);
+  
+      Object.setPrototypeOf(this, new.target.prototype);
+      this.name = Error.name;
+      this.statusCode = statusCode;
+      Error.captureStackTrace(this);
+    }
+}
+
+const requestLogger = (request: Request, response: Response, next: NextFunction) => {
+    console.log(`${request.method} url:: ${request.url}`);
+    next()
+}
+
+app.use(express.static('images'))  
+app.use(express.static('htmls'))  
+app.use(requestLogger)  
+
+app.use(morgan('tiny'))
+
+app.use('/products', express.json({ limit: 100 }))
+
+// Error handling Middleware functions
+const errorLogger = (error: Error, request: Request, response: Response, next: NextFunction) => {
+    console.log( `error ${error.message}`) 
+    next(error) // calling next middleware
+  }
+  
+  const errorResponder = (error: AppError, request: Request, response: Response, next: NextFunction) => {
+  response.header("Content-Type", 'application/json')
+    
+  const status = error.statusCode || 400
+  response.status(status).send(error.message)
+  }
+  const invalidPathHandler = (request: Request, response: Response, next: NextFunction) => {
+  response.status(400)
+  response.send('invalid path')
+  }
+  
+  
+  
+  app.get('product', (request: Request, response: Response)=>{
+    response.sendFile("productsample.html")
+  })
+  
+  // handle get request for path /
+  app.get('/', (request: Request, response: Response) => {
+      response.send('response for GET request');
+  })
+  
+  
+  const requireJsonContent = (request: Request, response: Response, next: NextFunction) => {
+    if (request.headers['content-type'] !== 'application/json') {
+        response.status(400).send('Server requires application/json')
+    } else {
+      next()
+    }
+  }
+
+
+const addProducts = (request: Request, response: Response, next: NextFunction) => {
+    let products: Product[] = []
+
+    const name: string = request.body.name                
+  
+    const brand: string = request.body.brand
+  
+    const category: string = request.body.category
+  
+    console.log(name + " " + brand)
+    
+    products.push({name: request.body.name, brand: request.body.brand, price: request.body.price})              
+   
+    const productCreationResponse: ProductCreationResponse = {productID: "12345", result: "success"}
+    response.json(productCreationResponse)
+
+    response.status(200).json(products);
+}
+app.post('/products', addProducts)
+
+app.get('/productswitherror', (request: Request, response: Response) => {
+    let error: AppError = new AppError(400, `processing error in request at ${request.url}`)
+    
+    throw error
+  })
+  
+  app.use(errorLogger)
+  app.use(errorResponder)
+  app.use(invalidPathHandler)
+
+app.listen(port, () => {
+    console.log(`Server listening at port ${port}.`)
+})

nodejs/middleware/htmls/productsample.html

@@ -0,0 +1,6 @@
+<html>
+<body>
+    <h2>My sample product page</h2>
+    <img src="sample.jpg" alt="sample"></img>
+</body>
+</html>

nodejs/middleware/images/sample.jpg

@@ -0,0 +1,89 @@
+const express = require('express')
+const morgan = require('morgan')
+
+const app = express();
+
+
+const requestLogger = (request, response, next) => {
+    console.log(`${request.method} url:: ${request.url}`);
+    next()
+}
+
+app.use(express.static('images'))  
+app.use(express.static('htmls'))  
+
+app.use(requestLogger)  
+
+app.use(morgan('tiny'))
+
+app.use('/products', express.json({ limit: 100 }))
+
+// Error handling Middleware functions
+const errorLogger = (error, request, response, next) => {
+  console.log( `error ${error.message}`) 
+  next(error) // calling next middleware
+}
+
+const errorResponder = (error, request, response, next) => {
+response.header("Content-Type", 'application/json')
+  
+const status = error.status || 400
+response.status(status).send(error.message)
+}
+const invalidPathHandler = (request, response, next) => {
+response.status(400)
+response.send('invalid path')
+}
+
+
+
+app.get('product', (request, response)=>{
+  response.sendFile("productsample.html")
+})
+
+// handle get request for path /
+app.get('/', (request, response) => {
+    response.send('response for GET request');
+})
+
+
+const requireJsonContent = (request, response, next) => {
+  if (request.headers['content-type'] !== 'application/json') {
+      response.status(400).send('Server requires application/json')
+  } else {
+    next()
+  }
+}
+
+// handle post request for path /products
+app.post('/products', requireJsonContent, (request, response) => {
+  const products = []
+
+  const name = request.body.name                
+
+  const brand = request.body.brand
+
+  const category = request.body.category
+
+  console.log(name + " " + brand)
+  
+  products.push({name: request.body.name, brand: request.body.brand, price: request.body.price})              
+ 
+  const productCreationResponse = {productID: "12345", result: "success"}
+  response.json(productCreationResponse)
+})
+
+app.get('/productswitherror', (request, response) => {
+  let error = new Error(`processing error in request at ${request.url}`)
+  error.statusCode = 400
+  throw error
+})
+
+app.use(errorLogger)
+app.use(errorResponder)
+app.use(invalidPathHandler)
+
+const port = 3000
+app.listen(3000, 
+     () => console.log(`Server listening on port ${port}.`));
+