I am trying to fetch data which is in JSON format. I am using maven dependency, testng and rest-assured. I want to test Rest API.BUT getting an error of java.lang.NullPointerException Here is my code -
public class CountBook {
@Test
public void BookCount (){
// Specify the base URL to the RESTful web service
RestAssured.baseURI = **URL HERE**
// Get the RequestSpecification of the request
RequestSpecification httpRequest = RestAssured.given();
Response response = httpRequest.get("");
// First get the JsonPath object instance from the Response interface
JsonPath jsonPathEvaluator = response.jsonPath();
List<HashMap<String, Object>> allBook = jsonPathEvaluator.get("books.findAll {it.pages == 352}");
int countingBook = allBook.size();
System.out.println(countingBook);
}
}
How can I get rid of this?int countingBook = allBook.size(); this line shows error. Here the list return null value.JSON is look like this
{
"books": [
{
"isbn": "9781593275846",
"title": "Eloquent JavaScript, Second Edition",
"subtitle": "A Modern Introduction to Programming",
"author": "Marijn Haverbeke",
"published": "2014-12-14T00:00:00.000Z",
"publisher": "No Starch Press",
"pages": 472,
"description": "JavaScript lies at the heart of almost every modern web application, from social apps to the newest browser-based games. Though simple for beginners to pick up and play with, JavaScript is a flexible, complex language that you can use to build full-scale applications.",
"website": "http://eloquentjavascript.net/"
},
{
"isbn": "9781491950296",
"title": "Programming JavaScript Applications",
"subtitle": "Robust Web Architecture with Node, HTML5, and Modern JS Libraries",
"author": "Eric Elliott",
"published": "2014-07-01T00:00:00.000Z",
"publisher": "O'Reilly Media",
"pages": 254,
"description": "Take advantage of JavaScript's power to build robust web-scale or enterprise applications that are easy to extend and maintain. By applying the design patterns outlined in this practical book, experienced JavaScript developers will learn how to write flexible and resilient code that's easier-yes, easier-to work with as your code base grows.",
"website": "http://chimera.labs.oreilly.com/books/1234000000262/index.html"
},
{
"isbn": "9781593277574",
"title": "Understanding ECMAScript 6",
"subtitle": "The Definitive Guide for JavaScript Developers",
"author": "Nicholas C. Zakas",
"published": "2016-09-03T00:00:00.000Z",
"publisher": "No Starch Press",
"pages": 352,
"description": "ECMAScript 6 represents the biggest update to the core of JavaScript in the history of the language. In Understanding ECMAScript 6, expert developer Nicholas C. Zakas provides a complete guide to the object types, syntax, and other exciting changes that ECMAScript 6 brings to JavaScript.",
"website": "https://leanpub.com/understandinges6/read"
},
{
"isbn": "9781491904244",
"title": "You Don't Know JS",
"subtitle": "ES6 & Beyond",
"author": "Kyle Simpson",
"published": "2015-12-27T00:00:00.000Z",
"publisher": "O'Reilly Media",
"pages": 278,
"description": "No matter how much experience you have with JavaScript, odds are you don’t fully understand the language. As part of the 'You Don’t Know JS' series, this compact guide focuses on new features available in ECMAScript 6 (ES6), the latest version of the standard upon which JavaScript is built.",
"website": "https://github.com/getify/You-Dont-Know-JS/tree/master/es6%20&%20beyond"
},
{
"isbn": "9781449337711",
"title": "Designing Evolvable Web APIs with ASP.NET",
"subtitle": "Harnessing the Power of the Web",
"author": "Glenn Block, et al.",
"published": "2014-04-07T00:00:00.000Z",
"publisher": "O'Reilly Media",
"pages": 538,
"description": "Design and build Web APIs for a broad range of clients—including browsers and mobile devices—that can adapt to change over time. This practical, hands-on guide takes you through the theory and tools you need to build evolvable HTTP services with Microsoft’s ASP.NET Web API framework. In the process, you’ll learn how design and implement a real-world Web API.",
"website": "http://chimera.labs.oreilly.com/books/1234000001708/index.html"
}
]
}
How can I resolve this problem?? Here is my stack trace
java.lang.NullPointerException
at CountBook.BookCount(CountBook.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:134)
at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:597)
at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:173)
at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46)
at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:816)
at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:146)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128)
at java.util.ArrayList.forEach(ArrayList.java:1249)
at org.testng.TestRunner.privateRun(TestRunner.java:766)
at org.testng.TestRunner.run(TestRunner.java:587)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:384)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:378)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:337)
at org.testng.SuiteRunner.run(SuiteRunner.java:286)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:53)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:96)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1187)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1109)
at org.testng.TestNG.runSuites(TestNG.java:1039)
at org.testng.TestNG.run(TestNG.java:1007)
at com.intellij.rt.testng.IDEARemoteTestNG.run(IDEARemoteTestNG.java:66)
at com.intellij.rt.testng.RemoteTestNGStarter.main(RemoteTestNGStarter.java:110)
In order to find one book you can use:
jsonPathEvaluator.get("books.find {it.pages == 352}").toString();
You can also make expected number of pages parameterized like this:
jsonPathEvaluator.param("expected", 352).get("books.find {it.pages == expected}").toString();
In order to find List<> you just use findAll instead of find
EDIT:
You used findAll method which returns a list of elements. You saved them to List<String> which is NOT a correct class.
Each book is a JSON Object and using. Each JSON Object is a HashMap<> of the String is a name of parameter, like pages or isbn. The other parameter is an Object because in your JSON there are Strings like author but also Integers like pages.
So, the correct code to collect the List would look like this:
List<HashMap<String, Object>> allBooks = jsonPathEvaluator.get("books.findAll {it.pages == 352}");
allBooks.forEach(book -> book.forEach((key, value) -> System.out.println(key + " " + value)));
and to count the number of books simply do what you did before:
int bookCount = allBooks.size();