BAEL-5737: Fix the JsonMappingException: Can not deserialize instance of java.util.ArrayList (#13837)

This commit is contained in:
Azhwani 2023-04-18 08:28:52 +02:00 committed by GitHub
parent 4663ee7fa8
commit 61b242fcfd
2 changed files with 61 additions and 10 deletions

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@ -0,0 +1,26 @@
package com.baeldung.mappingexception;
import java.util.List;
public class Country {
private String name;
private List<String> cities;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public List<String> getCities() {
return cities;
}
public void setCities(List<String> cities) {
this.cities = cities;
}
}

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@ -1,34 +1,33 @@
package com.baeldung.mappingexception; package com.baeldung.mappingexception;
import static org.hamcrest.Matchers.containsString; import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.not;
import static org.hamcrest.Matchers.notNullValue; import static org.hamcrest.Matchers.notNullValue;
import static org.junit.Assert.assertThat; import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertThrows;
import static org.junit.Assert.assertTrue;
import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.Arrays;
import java.io.IOException;
import java.util.List;
import org.junit.Test; import org.junit.Test;
import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility; import com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility;
import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.core.JsonGenerationException; import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.google.common.collect.Lists;
public class JacksonMappingExceptionUnitTest { public class JacksonMappingExceptionUnitTest {
@Test(expected = JsonMappingException.class) @Test(expected = JsonMappingException.class)
public final void givenObjectHasNoAccessors_whenSerializing_thenException() throws JsonParseException, IOException { public void givenObjectHasNoAccessors_whenSerializing_thenException() throws JsonProcessingException {
final String dtoAsString = new ObjectMapper().writeValueAsString(new MyDtoNoAccessors()); final String dtoAsString = new ObjectMapper().writeValueAsString(new MyDtoNoAccessors());
assertThat(dtoAsString, notNullValue()); assertThat(dtoAsString, notNullValue());
} }
@Test @Test
public final void givenObjectHasNoAccessors_whenSerializingWithPrivateFieldsVisibility_thenNoException() throws JsonParseException, IOException { public void givenObjectHasNoAccessors_whenSerializingWithPrivateFieldsVisibility_thenNoException() throws JsonProcessingException {
final ObjectMapper objectMapper = new ObjectMapper(); final ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setVisibility(PropertyAccessor.FIELD, Visibility.ANY); objectMapper.setVisibility(PropertyAccessor.FIELD, Visibility.ANY);
final String dtoAsString = objectMapper.writeValueAsString(new MyDtoNoAccessors()); final String dtoAsString = objectMapper.writeValueAsString(new MyDtoNoAccessors());
@ -39,7 +38,7 @@ public class JacksonMappingExceptionUnitTest {
} }
@Test @Test
public final void givenObjectHasNoAccessorsButHasVisibleFields_whenSerializing_thenNoException() throws JsonParseException, IOException { public void givenObjectHasNoAccessorsButHasVisibleFields_whenSerializing_thenNoException() throws JsonProcessingException {
final ObjectMapper objectMapper = new ObjectMapper(); final ObjectMapper objectMapper = new ObjectMapper();
final String dtoAsString = objectMapper.writeValueAsString(new MyDtoNoAccessorsAndFieldVisibility()); final String dtoAsString = objectMapper.writeValueAsString(new MyDtoNoAccessorsAndFieldVisibility());
@ -48,4 +47,30 @@ public class JacksonMappingExceptionUnitTest {
assertThat(dtoAsString, containsString("booleanValue")); assertThat(dtoAsString, containsString("booleanValue"));
} }
@Test
public void givenJsonWithInvalidList_whenDeserializing_thenThrowException() throws JsonProcessingException {
final String json = "{\"name\":\"Netherlands\",\"cities\":{\"Amsterdam\", \"Tamassint\"}}";
final ObjectMapper mapper = new ObjectMapper();
Exception exception = assertThrows(JsonMappingException.class, () -> mapper.reader()
.forType(Country.class)
.readValue(json));
assertTrue(exception.getMessage()
.contains("Cannot deserialize value of type `java.util.ArrayList<java.lang.String>`"));
}
@Test
public void givenJsonWithValidList_whenDeserializing_thenCorrect() throws JsonProcessingException {
final String json = "{\"name\":\"Netherlands\",\"cities\":[\"Amsterdam\", \"Tamassint\"]}";
final ObjectMapper mapper = new ObjectMapper();
Country country = mapper.reader()
.forType(Country.class)
.readValue(json);
assertEquals("Netherlands", country.getName());
assertEquals(Arrays.asList("Amsterdam", "Tamassint"), country.getCities());
}
} }