当我序列化/反序列化任何对象时,所有字段名称都转换为小写。 是否有任何配置可以让Jackson完全保留字段名称?用于序列化和反序列化?
(我知道@JsonProperty,但这似乎不对,因为我需要的只是杰克逊尊重已经存在的东西)
我的测试代码:
import java.io.Serializable;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.PropertyNamingStrategy;
import com.fasterxml.jackson.databind.SerializationFeature;
import com.fasterxml.jackson.databind.cfg.MapperConfig;
import com.fasterxml.jackson.databind.introspect.AnnotatedField;
import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
public class Test {
static class Example implements Serializable {
private String Test;
private String ABC;
private String XyZ;
public String getTest() { return Test; }
public void setTest(String test) { Test = test; }
public String getABC() { return ABC; }
public void setABC(String abc) { ABC = abc; }
public String getXyZ() { return XyZ; }
public void setXyZ(String xyz) { XyZ = xyz; }
}
static class MyPropertyNamingStrategy extends PropertyNamingStrategy {
@Override
public String nameForField(MapperConfig<?> config, AnnotatedField field, String defaultName) {
return convert(defaultName);
}
@Override
public String nameForGetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convert(defaultName);
}
@Override
public String nameForSetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convert(defaultName);
}
private String convert(String input) {
return input;
}
}
public static void main(String[] args) throws Exception {
ObjectMapper objectMapper = new ObjectMapper()
.setPropertyNamingStrategy(new MyPropertyNamingStrategy())
.enable(SerializationFeature.INDENT_OUTPUT)
.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
//From OBJECT to JSON
Example ex = new Example();
ex.setTest("1");
ex.setABC("2");
ex.setXyZ("3");
System.out.println(objectMapper.writeValueAsString(ex));
//FROM JSON to OBJECT
String jsonString = "{ \"Test\":\"0\", \"ABC\":\"1\", \"XyZ\":\"2\" }";
Example fEx = objectMapper.readValue(jsonString, Example.class);
}
}
感谢@ BlueLettuce16,我成功地建立了一个改进的&#39; PropertyNamingStrategy
的版本。这是:
import java.lang.reflect.Modifier;
import com.fasterxml.jackson.databind.PropertyNamingStrategy;
import com.fasterxml.jackson.databind.cfg.MapperConfig;
import com.fasterxml.jackson.databind.introspect.AnnotatedField;
import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
public class CustomPropertyNamingStrategy extends PropertyNamingStrategy {
@Override
public String nameForField(MapperConfig<?> config, AnnotatedField field, String defaultName) {
return convertForField(defaultName);
}
@Override
public String nameForGetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convertForMethod(method, defaultName);
}
@Override
public String nameForSetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convertForMethod(method, defaultName);
}
private String convertForField(String defaultName) {
return defaultName;
}
private String convertForMethod(AnnotatedMethod method, String defaultName) {
if (isGetter(method)) {
return method.getName().substring(3);
}
if (isSetter(method)) {
return method.getName().substring(3);
}
return defaultName;
}
private boolean isGetter(AnnotatedMethod method) {
if (Modifier.isPublic(method.getModifiers()) && method.getGenericParameterTypes().length == 0) {
if (method.getName().matches("^get[A-Z].*") && !method.getGenericReturnType().equals(void.class))
return true;
if (method.getName().matches("^is[A-Z].*") && method.getGenericReturnType().equals(boolean.class))
return true;
}
return false;
}
private boolean isSetter(AnnotatedMethod method) {
return Modifier.isPublic(method.getModifiers()) && method.getGenericReturnType().equals(void.class) && method.getGenericParameterTypes().length == 1
&& method.getName().matches("^set[A-Z].*");
}
}
答案 0 :(得分:7)
我遇到了同样的问题。
这是我的解决方案:
public class MyNamingStrategy extends PropertyNamingStrategy {
@Override
public String nameForField(MapperConfig<?> config, AnnotatedField field, String defaultName) {
return field.getName();
}
@Override
public String nameForGetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convert(method, defaultName);
}
@Override
public String nameForSetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convert(method, defaultName);
}
private String convert(AnnotatedMethod method, String defaultName) {
Class<?> clazz = method.getDeclaringClass();
List<Field> flds = FieldUtils.getAllFieldsList(clazz);
for (Field fld : flds) {
if (fld.getName().equalsIgnoreCase(defaultName)) {
return fld.getName();
}
}
return defaultName;
}
}
在这种情况下,您将获得属性的确切名称,而不必依赖于方法的正确名称。
答案 1 :(得分:4)
我认为这是解决方案(使用自定义PropertyNamingStrategy):
import com.fasterxml.jackson.databind.PropertyNamingStrategy;
import com.fasterxml.jackson.databind.cfg.MapperConfig;
import com.fasterxml.jackson.databind.introspect.AnnotatedField;
import com.fasterxml.jackson.databind.introspect.AnnotatedMethod;
public class MyPropertyNamingStrategy extends PropertyNamingStrategy {
@Override
public String nameForField(MapperConfig<?> config, AnnotatedField field, String defaultName) {
return convert(field.getName());
}
@Override
public String nameForGetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convert(method.getName().toString());
}
@Override
public String nameForSetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
return convert(method.getName().toString());
}
private String convert(String input) {
return input.substring(3);
}
}
测试
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;
import java.io.IOException;
import java.io.StringWriter;
public class MyPropertyNamingStrategyTest {
public static void main(String[] args) {
PrivatePerson privatePerson = new PrivatePerson();
privatePerson.setFirstName("John");
privatePerson.setLastName("Smith");
ObjectMapper mapper = new ObjectMapper();
mapper.setPropertyNamingStrategy(new MyPropertyNamingStrategy());
mapper.enable(SerializationFeature.INDENT_OUTPUT);
StringWriter sw = new StringWriter();
try {
mapper.writeValue(sw, privatePerson);
} catch (IOException e) {
e.printStackTrace();
}
System.out.println(sw.toString());
}
}
PrivatePerson
public class PrivatePerson {
private String firstName;
private String lastName;
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getFirstName() {
return firstName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public String getLastName() {
return lastName;
}
}
答案 2 :(得分:1)
您可以将Jackson配置为区分大小写:
ObjectMapper mapper = new ObjectMapper();
mapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);
答案 3 :(得分:1)
即使@JsonProperty
不起作用,我仍然可以使用@JsonSetter
和@JsonGetter
映射大写的json字段名称。
@JsonSetter("ABC")
public void setABC(String ABC) {
this.ABC= ABC;
}
Spring现在会将对象字段序列化为“ ABC”而不是“ abc”。