BAEL-6508 Code for the Solving Gson Parsing Errors article

2023-05-22 10:16:59 +02:00
parent a0931c50ce
commit e42d7a6b8a
5 changed files with 105 additions and 0 deletions
@@ -0,0 +1,55 @@
+package com.baeldung.gson.parsingerror;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.lang.reflect.Type;
+import java.util.Collection;
+
+import org.junit.jupiter.api.Test;
+
+import com.baeldung.gson.parsingerrors.Person;
+import com.google.gson.Gson;
+import com.google.gson.JsonSyntaxException;
+import com.google.gson.reflect.TypeToken;
+
+class GsonErrorDemoUnitTest {
+
+    @Test
+    void givenAJsonArray_WhenTellingGsonToExpectAnObject_ThenThrows() {
+        assertThrows(JsonSyntaxException.class, () -> {
+            Person person = new Gson().fromJson("[{\"name\":\"John\"},{\"name\":\"James\"}]", Person.class);
+        });
+    }
+
+    @Test
+    void givenAJsonArray_WhenParsingIntoAnArray_ThenOK() {
+        Person[] personArray = new Gson().fromJson("[{\"name\":\"John\"},{\"name\":\"James\"}]", Person[].class);
+        assertThat(personArray).extracting(Person::getName)
+          .containsExactly("John", "James");
+    }
+
+    @Test
+    void givenAJsonArray_WhenParsingIntoACollection_ThenOK() {
+        Type collectionType = new TypeToken<Collection<Person>>() {
+        }.getType();
+        Collection<Person> personCollection = new Gson().fromJson("[{\"name\":\"John\"},{\"name\":\"James\"}]", collectionType);
+        assertThat(personCollection).extracting(Person::getName)
+          .containsExactly("John", "James");
+    }
+
+    @Test
+    void givenAJsonObject_WhenTellingGsonToExpectAnArray_ThenThrows() {
+        assertThrows(JsonSyntaxException.class, () -> {
+            Person[] personArray = new Gson().fromJson("{\"name\":\"John\"}", Person[].class);
+        });
+    }
+
+    @Test
+    void givenAJsonObject_WhenParsingIntoAnObject_ThenOK() {
+        Person person = new Gson().fromJson("{\"name\":\"John\"}", Person.class);
+        assertEquals("John", person.getName());
+    }
+
+}