OperationIntegrationTest.java

package com.baeldung.jsonpath.introduction;

import com.jayway.jsonpath.Criteria;
import com.jayway.jsonpath.DocumentContext;
import com.jayway.jsonpath.Filter;
import com.jayway.jsonpath.JsonPath;
import com.jayway.jsonpath.Predicate;
import org.junit.Test;

import java.io.InputStream;
import java.util.List;
import java.util.Map;
import java.util.Scanner;

import static org.hamcrest.CoreMatchers.containsString;
import static org.hamcrest.CoreMatchers.not;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;

public class OperationIntegrationTest {
    private InputStream jsonInputStream = this.getClass()
        .getClassLoader()
        .getResourceAsStream("intro_api.json");
    private String jsonDataSourceString = new Scanner(jsonInputStream, "UTF-8").useDelimiter("\\Z")
        .next();

    @Test
    public void givenJsonPathWithoutPredicates_whenReading_thenCorrect() {
        String jsonpathCreatorNamePath = "$['tool']['jsonpath']['creator']['name']";
        String jsonpathCreatorLocationPath = "$['tool']['jsonpath']['creator']['location'][*]";

        DocumentContext jsonContext = JsonPath.parse(jsonDataSourceString);
        String jsonpathCreatorName = jsonContext.read(jsonpathCreatorNamePath);
        List<String> jsonpathCreatorLocation = jsonContext.read(jsonpathCreatorLocationPath);

        assertEquals("Jayway Inc.", jsonpathCreatorName);
        assertThat(jsonpathCreatorLocation.toString(), containsString("Malmo"));
        assertThat(jsonpathCreatorLocation.toString(), containsString("San Francisco"));
        assertThat(jsonpathCreatorLocation.toString(), containsString("Helsingborg"));
    }

    @Test
    public void givenJsonPathWithFilterPredicate_whenReading_thenCorrect() {
        Filter expensiveFilter = Filter.filter(Criteria.where("price")
            .gt(20.00));
        List<Map<String, Object>> expensive = JsonPath.parse(jsonDataSourceString)
            .read("$['book'][?]", expensiveFilter);
        predicateUsageAssertionHelper(expensive);
    }

    @Test
    public void givenJsonPathWithCustomizedPredicate_whenReading_thenCorrect() {
        Predicate expensivePredicate = context -> Float.valueOf(context.item(Map.class)
            .get("price")
            .toString()) > 20.00;
        List<Map<String, Object>> expensive = JsonPath.parse(jsonDataSourceString)
            .read("$['book'][?]", expensivePredicate);
        predicateUsageAssertionHelper(expensive);
    }

    @Test
    public void givenJsonPathWithInlinePredicate_whenReading_thenCorrect() {
        List<Map<String, Object>> expensive = JsonPath.parse(jsonDataSourceString)
            .read("$['book'][?(@['price'] > $['price range']['medium'])]");
        predicateUsageAssertionHelper(expensive);
    }

    private void predicateUsageAssertionHelper(List<?> predicate) {
        assertThat(predicate.toString(), containsString("Beginning JSON"));
        assertThat(predicate.toString(), containsString("JSON at Work"));
        assertThat(predicate.toString(), not(containsString("Learn JSON in a DAY")));
        assertThat(predicate.toString(), not(containsString("JSON: Questions and Answers")));
    }
}