A library is using Map to use some extra information. This map eventually is being converted a JSON object and I need to set request information to display for debugging purposes as this:
map.put("request", requestString);
I am considering to use Jackson specifically to create a JSON without quotes and want to set as requestString.
I am building necessary information regarding Request and building a Map including request headers, parameters, method etc.
Jackson is creating perfectly valid JSON with quotes but when I set this generated value inside map, It is displayed ugly because of having escaped quotes.
So Jackson is creating this:
{
method : "POST",
path : "/register"
}
When I set this in map, it turns to this:
{
method : \"POST\",
path : \"/register\"
}
Consider this as a huge map including all parameters and other information about request.
What I would like to want this:
{
method : POST,
path : /register
}
I know that this is not a valid JSON but I am using this as a String to a Map which is accepting String values.
public class UnQuotesSerializer extends NonTypedScalarSerializerBase<String>
{
public UnQuotesSerializer() { super(String.class); }
/**
* For Strings, both null and Empty String qualify for emptiness.
*/
#Override
public boolean isEmpty(String value) {
return (value == null) || (value.length() == 0);
}
#Override
public void serialize(String value, JsonGenerator jgen, SerializerProvider provider) throws IOException {
jgen.writeRawValue(value);
}
#Override
public JsonNode getSchema(SerializerProvider provider, Type typeHint) {
return createSchemaNode("string", true);
}
#Override
public void acceptJsonFormatVisitor(JsonFormatVisitorWrapper visitor, JavaType typeHint) throws JsonMappingException {
if (visitor != null) visitor.expectStringFormat(typeHint);
}
}
and
ObjectMapper objectMapper = new ObjectMapper();
SimpleModule module = new SimpleModule("UnQuote");
module.addSerializer(new UnQuotesSerializer());
objectMapper.configure(JsonGenerator.Feature.QUOTE_FIELD_NAMES, false);
objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true);
objectMapper.registerModule(module);
This is generating without quotes strings.
The following test passes (Jackson 2.5.0)
#Test
public void test() throws Exception {
ObjectMapper mapper = new ObjectMapper();
Map map = new HashMap();
map.put("method", "POST");
map.put("request", "/register");
String s = mapper.writeValueAsString(map);
Map map2 = mapper.readValue(s, Map.class);
Assert.assertEquals(map, map2);
}
so your pseudo JSON without quotes does not seem the way to go
Related
This might be a duplicate. But I cannot find a solution to my Problem.
I have a class
public class MyResponse implements Serializable {
private boolean isSuccess;
public boolean isSuccess() {
return isSuccess;
}
public void setSuccess(boolean isSuccess) {
this.isSuccess = isSuccess;
}
}
Getters and setters are generated by Eclipse.
In another class, I set the value to true, and write it as a JSON string.
System.out.println(new ObjectMapper().writeValueAsString(myResponse));
In JSON, the key is coming as {"success": true}.
I want the key as isSuccess itself. Is Jackson using the setter method while serializing? How do I make the key the field name itself?
This is a slightly late answer, but may be useful for anyone else coming to this page.
A simple solution to changing the name that Jackson will use for when serializing to JSON is to use the #JsonProperty annotation, so your example would become:
public class MyResponse implements Serializable {
private boolean isSuccess;
#JsonProperty(value="isSuccess")
public boolean isSuccess() {
return isSuccess;
}
public void setSuccess(boolean isSuccess) {
this.isSuccess = isSuccess;
}
}
This would then be serialised to JSON as {"isSuccess":true}, but has the advantage of not having to modify your getter method name.
Note that in this case you could also write the annotation as #JsonProperty("isSuccess") as it only has the single value element
I recently ran into this issue and this is what I found. Jackson will inspect any class that you pass to it for getters and setters, and use those methods for serialization and deserialization. What follows "get", "is" and "set" in those methods will be used as the key for the JSON field ("isValid" for getIsValid and setIsValid).
public class JacksonExample {
private boolean isValid = false;
public boolean getIsValid() {
return isValid;
}
public void setIsValid(boolean isValid) {
this.isValid = isValid;
}
}
Similarly "isSuccess" will become "success", unless renamed to "isIsSuccess" or "getIsSuccess"
Read more here: http://www.citrine.io/blog/2015/5/20/jackson-json-processor
Using both annotations below, forces the output JSON to include is_xxx:
#get:JsonProperty("is_something")
#param:JsonProperty("is_something")
When you are using Kotlin and data classes:
data class Dto(
#get:JsonProperty("isSuccess") val isSuccess: Boolean
)
You might need to add #param:JsonProperty("isSuccess") if you are going to deserialize JSON as well.
EDIT: If you are using swagger-annotations to generate documentation, the property will be marked as readOnly when using #get:JsonProperty. In order to solve this, you can do:
#JsonAutoDetect(isGetterVisibility = JsonAutoDetect.Visibility.NONE)
data class Dto(
#field:JsonProperty(value = "isSuccess") val isSuccess: Boolean
)
You can configure your ObjectMapper as follows:
mapper.setPropertyNamingStrategy(new PropertyNamingStrategy() {
#Override
public String nameForGetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName)
{
if(method.hasReturnType() && (method.getRawReturnType() == Boolean.class || method.getRawReturnType() == boolean.class)
&& method.getName().startsWith("is")) {
return method.getName();
}
return super.nameForGetterMethod(config, method, defaultName);
}
});
I didn't want to mess with some custom naming strategies, nor re-creating some accessors.
The less code, the happier I am.
This did the trick for us :
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
import com.fasterxml.jackson.annotation.JsonProperty;
#JsonIgnoreProperties({"success", "deleted"}) // <- Prevents serialization duplicates
public class MyResponse {
private String id;
private #JsonProperty("isSuccess") boolean isSuccess; // <- Forces field name
private #JsonProperty("isDeleted") boolean isDeleted;
}
Building upon Utkarsh's answer..
Getter names minus get/is is used as the JSON name.
public class Example{
private String radcliffe;
public getHarryPotter(){
return radcliffe;
}
}
is stored as { "harryPotter" : "whateverYouGaveHere" }
For Deserialization, Jackson checks against both the setter and the field name.
For the Json String { "word1" : "example" }, both the below are valid.
public class Example{
private String word1;
public setword2( String pqr){
this.word1 = pqr;
}
}
public class Example2{
private String word2;
public setWord1(String pqr){
this.word2 = pqr ;
}
}
A more interesting question is which order Jackson considers for deserialization. If i try to deserialize { "word1" : "myName" } with
public class Example3{
private String word1;
private String word2;
public setWord1( String parameter){
this.word2 = parameter ;
}
}
I did not test the above case, but it would be interesting to see the values of word1 & word2 ...
Note: I used drastically different names to emphasize which fields are required to be same.
You can change primitive boolean to java.lang.Boolean (+ use #JsonPropery)
#JsonProperty("isA")
private Boolean isA = false;
public Boolean getA() {
return this.isA;
}
public void setA(Boolean a) {
this.isA = a;
}
Worked excellent for me.
If you are interested in handling 3rd party classes not under your control (like #edmundpie mentioned in a comment) then you add Mixin classes to your ObjectMapper where the property/field names should match the ones from your 3rd party class:
public class MyStack32270422 {
public static void main(String[] args) {
ObjectMapper om3rdParty = new ObjectMapper();
om3rdParty .addMixIn(My3rdPartyResponse.class, MixinMyResponse.class);
// add further mixins if required
String jsonString = om3rdParty.writeValueAsString(new My3rdPartyResponse());
System.out.println(jsonString);
}
}
class MixinMyResponse {
// add all jackson annotations here you want to be used when handling My3rdPartyResponse classes
#JsonProperty("isSuccess")
private boolean isSuccess;
}
class My3rdPartyResponse{
private boolean isSuccess = true;
// getter and setter here if desired
}
Basically you add all your Jackson annotations to your Mixin classes as if you would own the class. In my opinion quite a nice solution as you don't have to mess around with checking method names starting with "is.." and so on.
there is another method for this problem.
just define a new sub-class extends PropertyNamingStrategy and pass it to ObjectMapper instance.
here is a code snippet may be help more:
mapper.setPropertyNamingStrategy(new PropertyNamingStrategy() {
#Override
public String nameForGetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName) {
String input = defaultName;
if(method.getName().startsWith("is")){
input = method.getName();
}
//copy from LowerCaseWithUnderscoresStrategy
if (input == null) return input; // garbage in, garbage out
int length = input.length();
StringBuilder result = new StringBuilder(length * 2);
int resultLength = 0;
boolean wasPrevTranslated = false;
for (int i = 0; i < length; i++)
{
char c = input.charAt(i);
if (i > 0 || c != '_') // skip first starting underscore
{
if (Character.isUpperCase(c))
{
if (!wasPrevTranslated && resultLength > 0 && result.charAt(resultLength - 1) != '_')
{
result.append('_');
resultLength++;
}
c = Character.toLowerCase(c);
wasPrevTranslated = true;
}
else
{
wasPrevTranslated = false;
}
result.append(c);
resultLength++;
}
}
return resultLength > 0 ? result.toString() : input;
}
});
The accepted answer won't work for my case.
In my case, the class is not owned by me. The problematic class comes from 3rd party dependencies, so I can't just add #JsonProperty annotation in it.
To solve it, inspired by #burak answer above, I created a custom PropertyNamingStrategy as follow:
mapper.setPropertyNamingStrategy(new PropertyNamingStrategy() {
#Override
public String nameForSetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName)
{
if (method.getParameterCount() == 1 &&
(method.getRawParameterType(0) == Boolean.class || method.getRawParameterType(0) == boolean.class) &&
method.getName().startsWith("set")) {
Class<?> containingClass = method.getDeclaringClass();
String potentialFieldName = "is" + method.getName().substring(3);
try {
containingClass.getDeclaredField(potentialFieldName);
return potentialFieldName;
} catch (NoSuchFieldException e) {
// do nothing and fall through
}
}
return super.nameForSetterMethod(config, method, defaultName);
}
#Override
public String nameForGetterMethod(MapperConfig<?> config, AnnotatedMethod method, String defaultName)
{
if(method.hasReturnType() && (method.getRawReturnType() == Boolean.class || method.getRawReturnType() == boolean.class)
&& method.getName().startsWith("is")) {
Class<?> containingClass = method.getDeclaringClass();
String potentialFieldName = method.getName();
try {
containingClass.getDeclaredField(potentialFieldName);
return potentialFieldName;
} catch (NoSuchFieldException e) {
// do nothing and fall through
}
}
return super.nameForGetterMethod(config, method, defaultName);
}
});
Basically what this does is, before serializing and deserializing, it checks in the target/source class which property name is present in the class, whether it is isEnabled or enabled property.
Based on that, the mapper will serialize and deserialize to the property name that is exist.
I try to call my AWS Lambda function (serverless backend) with my Android mobile app client. The AWS lambda function returns an ArrayList of POJO objects (as JSON).
The problem is that the android client AWS Lambda(JSON)DataBinder does not deserialize to my ArrayList of POJOs. I get an ArrayList of LinkedTreeMap (see code at onPostExecute() below).
At the android client side I'm using Android AWS SDK: com.amazonaws:aws-android-sdk-core:2.6
Here is some code:
public void readSurveyList(String strUuid, int intLanguageID) {
// Create an instance of CognitoCachingCredentialsProvider
// You have to configure at least an AWS identity pool to get access to your lambda function
CognitoCachingCredentialsProvider credentialsProvider = new CognitoCachingCredentialsProvider(
this.getApplicationContext(),
IDENTITY_POOL_ID,
Regions.EU_CENTRAL_1);
LambdaInvokerFactory factory = LambdaInvokerFactory.builder()
.context(this.getApplicationContext())
.region(Regions.EU_CENTRAL_1)
.credentialsProvider(credentialsProvider)
.build();
// Create the Lambda proxy object with default Json data binder.
myInterface = factory.build(MyInterface.class);
//create a request object (depends on your lambda function)
SurveyListRequest surveyListRequest = new SurveyListRequest(strUuid, intLanguageID);
// Lambda function in async task with definiton of
// request object (-> SurveyListRequest)
// response object (-> ArrayList<SurveyListItem>>)
new AsyncTask<SurveyListRequest, Void, ArrayList<SurveyListItem>>() {
#Override
protected ArrayList<SurveyListItem> doInBackground(SurveyListRequest... params) {
try {
return myInterface.ReadSurveyList(params[0]);
} catch (LambdaFunctionException lfe) {
Log.e("TAG", String.format("echo method failed: error [%s], details [%s].", lfe.getMessage(), lfe.getDetails()));
return null;
}
}
#Override
protected void onPostExecute(ArrayList<SurveyListItem> surveyList) {
// PROBLEM: here i get a ArrayList of LinkedTreeMap
}
}.execute(surveyListRequest);
}
Here is the code of my lambda function Interface:
public interface MyInterface {
#LambdaFunction
ArrayList<SurveyListItem> ReadSurveyList (SurveyListRequest surveyListRequest);
}
I would expect to get a list of my POJO objects. I found a lot of discussions about Gson and ArrayList type and solutions based on TypeToken (e.g. Gson TypeToken with dynamic ArrayList item type). Maybe same problem ...
I found a solution using a custom LambdaDataBinder. I have specified the type of my POJO-class "SurveyListItem" in deserialize function. The Gson uses the TypeToken definition and converts the JSON string correct to the list of POJOs (in my case "SurveyListItem" objects).
Here is the sourcecode of MyLambdaDataBinder:
public class MyLambdaDataBinder implements LambdaDataBinder {
private final Gson gson;
Type mType;
//CUSTOMIZATION: pass typetoken via class constructor
public MyLambdaDataBinder(Type type) {
this.gson = new Gson();
mType = type;
}
#Override
public <T> T deserialize(byte[] content, Class<T> clazz) {
if (content == null) {
return null;
}
Reader reader = new BufferedReader(new InputStreamReader(new ByteArrayInputStream(content)));
//CUSTOMIZATION: Original line of code: return gson.fromJson (reader, clazz);
return gson.fromJson(reader, mType);
}
#Override
public byte[] serialize(Object object) {
return gson.toJson(object).getBytes(StringUtils.UTF8);
}
}
Here is how to use the custom MyLambdaDataBinder. Use your POJO instead of "SurveyListItem":
myInterface = factory.build(LambdaInterface.class, new MyLambdaDataBinder(new TypeToken<ArrayList<SurveyListItem>>() {}.getType()));
I am using a library com.fasterxml.jackson library for JsonSchema,
I am creating an IntegerSchema object, when I set range for integer schema using below code:
main(){
IntegerSchema intSchema = new IntegerSchema();
// setMaximum accepts Double object
intSchema.setMaximum(new Double(102000000));
// setMaximum accepts Double object
intSchema.setMinimum(new Double(100));
printJsonSchema(intSchema);
}
public void printJsonSchema(JsonSchema schema){
ObjectMapper mapper = new ObjectMapper();
try {
logger.info(mapper.writeValueAsString(schema));
} catch (JsonProcessingException e) {
throw new IllegalStateException(e);
}
}
When I convert IntegerSchema to string using ObjectMapper getting below response:
{"type":"integer","maximum":1.02E8,"minimum":100.0}
maximum and minimum values are getting converted to scientific notation.
But I need output in non scientific notation as below:
{"type":"integer","maximum":102000000,"minimum":100}
I cannot change IntegerSchema class.
Please suggest how to get the required output without extending IntegerSchema class?
Thanks in advance
this is a java issue somewhat I believe. If you debug your program, your Double will always be displayed scientifically, so what we'll want is to force it into a String. This can be achieved in Java in multiple ways, and you can look it up here:
How to print double value without scientific notation using Java?
In terms of your specific question about Jackson, I've written up some code for you:
public class ObjectMapperTest {
public static void main(String[] args) throws JsonProcessingException {
IntegerSchema schema = new IntegerSchema();
schema.type = "Int";
schema.max = 10200000000d;
schema.min = 100d;
ObjectMapper m = new ObjectMapper();
System.out.println(m.writeValueAsString(schema));
}
public static class IntegerSchema {
#JsonProperty
String type;
#JsonProperty
double min;
#JsonProperty
#JsonSerialize(using=MyDoubleDesirializer.class)
double max;
}
public static class MyDoubleDesirializer extends JsonSerializer<Double> {
#Override
public void serialize(Double value, JsonGenerator gen, SerializerProvider serializers)
throws IOException, JsonProcessingException {
// TODO Auto-generated method stub
BigDecimal d = new BigDecimal(value);
gen.writeNumber(d.toPlainString());
}
}
}
The trick is to register a custom Serializer for your Double value. This way, you can control what you want.
I am using the BigDecimal value to create a String representation of your Double. The output then becomes (for the specific example):
{"type":"Int","min":100.0,"max":10200000000}
I hope that solves your problem.
Artur
Feature.WRITE_BIGDECIMAL_AS_PLAIN
set this for your Object Mapper
I know I am answering late, but something I faced may help other
While converting a BigDecimal I have faced below is working
mapper = mapper.setNodeFactory(JsonNodeFactory.withExactBigDecimals(true));
while this is not working for me
mapper.configure(JsonGenerator.Feature.WRITE_BIGDECIMAL_AS_PLAIN, true);
Update for Jakson 2.9.10:
Property WRITE_BIGDECIMAL_AS_PLAIN replaced to com.fasterxml.jackson.core.JsonGenerator. You could use:
mapper.enable(JsonGenerator.Feature.WRITE_BIGDECIMAL_AS_PLAIN);
If you are using ValueToTree then no need of any factory settings. only problem with ValueToTree is it is converting as TextNode (String Fromat), So if you have any logic based on ObjectNodes it will not work
You should use
mapper.configure(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS, true);
To avoid scientific notation on floating numbers.
You can find an example below.
ObjectMapper mapper = new ObjectMapper();
mapper.configure(DeserializationFeature.USE_BIG_DECIMAL_FOR_FLOATS, true);
String test ="{\"doubleValue\" : 0.00001}";
try {
System.out.println(mapper.readTree(test).toPrettyString());
} catch (JsonProcessingException e) {
e.printStackTrace();
}
Output
{
"doubleValue" : 0.00001
}
I have document type which contains "Dynamic Dropdown" field, and I want to fill it with some dynamic data. I couldn't figure out how to do it (couldn't find any adequate information, documentation, example about this). From links that I found I was able to do following things:
1) I've created service called SitemapValueListProvider in /hippo:configuration/hippo:frontend/cms/cms-services, with following properties:
plugin.class = com.test.cms.components.SitemapService
valuelist.provider = service.valuelist.custom
2) In CMS project created class com.test.cms.components.SitemapService
public class SitemapService extends Plugin implements IValueListProvider {
private final static String CONFIG_SOURCE = "source";
public SitemapService(IPluginContext context, IPluginConfig config) {
super(context, config);
String name = config.getString(IValueListProvider.SERVICE, "service.valuelist.custom");
context.registerService(this, name);
}
#Override
public ValueList getValueList(String name, Locale locale) {
ValueList valuelist = new ValueList();
if ((name == null) || (name.equals(""))) {
System.out.println("No node name (uuid or path) configured, returning empty value list");
} else {
valuelist.add(new ListItem("custom4", "Custom Value 4"));
valuelist.add(new ListItem("custom5", "Custom Value 5"));
valuelist.add(new ListItem("custom6", "Custom Value 6"));
}
return valuelist;
}
#Override
public List<String> getValueListNames() {
List<String> list = new ArrayList<>(1);
list.add("values");
return list;
}
#Override
public ValueList getValueList(IPluginConfig config) {
if (config == null) {
throw new IllegalArgumentException("Argument 'config' may not be null");
}
return getValueList(config.getString(CONFIG_SOURCE));
}
#Override
public ValueList getValueList(String name) {
return getValueList(name, null/*locale*/);
}
}
3) In CMS project created class com.test.cms.components.TestPlugin
public class TestPlugin extends Plugin{
public TestPlugin(IPluginContext context, IPluginConfig config) {
super(context, config);
context.registerService(this, "service.valuelist.custom");
}
}
4) For field /hippo:namespaces/cms/TestItem/editor:templates/_default_/dynamicdropdown of document type provided following properties: (using console)
plugin.class = com.test.cms.components.TestPlugin
But still unable to obtain data dynamically. Nothing happens at all.
I'm using HippoCMS 10 Community Edition
you are totally on the right track and I can't spot any obvious reason why this is not working. Can you double check a few things?
look for an error in the logs, possibly at the early start of the CMS. Maybe there is an error during the bootstrap process.
activate the development mode in the CMS: this adds extra logging in the CMS.
http://www.onehippo.org/library/development/debug-wicket-ajax-in-the-cms.html
you can also try to break the configuration by putting the wrong class name: if you don't have a ClassNotFound then you know your configuration is wrong and/or not picked-up.
HTH.
I'm using a HeaderColumnNameMappingStrategy to map a csv file with a header into a JavaBean. String values parse fine but any "true" or "false" value in csv doesn't map to JavaBean and I get the following exception from the PropertyDescriptor:
java.lang.IllegalArgumentException: argument type mismatch
The code where it occurs is in CsvToBean, line 64:
protected T processLine(MappingStrategy<T> mapper, String[] line) throws
IllegalAccessException, InvocationTargetException, InstantiationException, IntrospectionException {
T bean = mapper.createBean();
for(int col = 0; col < line.length; col++) {
String value = line[col];
PropertyDescriptor prop = mapper.findDescriptor(col);
if (null != prop) {
Object obj = convertValue(value, prop);
// this is where exception is thrown for a "true" value in csv
prop.getWriteMethod().invoke(bean, new Object[] {obj});
}
}
return bean;
}
protected PropertyEditor getPropertyEditor(PropertyDescriptor desc) throws
InstantiationException, IllegalAccessException {
Class<?> cls = desc.getPropertyEditorClass();
if (null != cls) return (PropertyEditor) cls.newInstance();
return getPropertyEditorValue(desc.getPropertyType());
}
I can confirm (via debugger) that the setter method id correctly retrieved at this point.
The problem occurs in desc.getPropertyEditorClass() since it returns null. I assumed primitive types and its wrappers are supported. Are they not?
I've run into this same issue. The cleanest way is probably to override getPropertyEditor like pritam did above and return a custom PropertyEditor for your particular object. The quick and dirty way would be to override convertValue in anonymous class form, like this:
CsvToBean<MyClass> csvToBean = new CsvToBean<MyClass>(){
#Override
protected Object convertValue(String value, PropertyDescriptor prop) throws InstantiationException,IllegalAccessException {
if (prop.getName().equals("myWhatever")) {
// return an custom object based on the incoming value
return new MyWhatever((String)value);
}
return super.convertValue(value, prop);
}
};
This is working fine for me with OpenCSV 2.3. Good luck!
I resolved this by extending CsvToBean and adding my own PropertyEditors. Turns out opencsv just supports primitive types and no wrappers.
Pritam's answer is great and this is a sample for dealing with datetime format.
PropertyEditorManager.registerEditor(java.util.Date.class, DateEditor.class);
You should write your own editor class like this:
public class DateEditor extends PropertyEditorSupport{
public static final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
#Override
public void setAsText(String text){
setValue(sdf.parse(text));}
}