EzToJson

Java-classes to JSON converter for use during development.

Main feature - scanning depth. Zero means that only this class will be showed fully in JSONObject, and increasing this value by one you'll get one more layer of scanning.

Download

Maven dependency:

<dependency>
  <groupId>com.a6raywa1cher</groupId>
  <artifactId>eztojson</artifactId>
  <version>1.0.1</version>
</dependency>

Jar file also in releases tab. In this case, you need to download https://github.com/stleary/JSON-java too.

Usage

Fast setup

1. Be sure to make getters for all necessary fields
2. Receive object of ETJReference: ETJUtility.create(Adapter)
   1. If you plan to parse classes with JPA annotations (e.g., @Column, @Id, @Transient), use JPAAdapter.
   2. In other cases, use POJOAdapter or implement Adapter. You probably would like to set @ShortInfo annotation.
3. Set up necessary parameters: etjReference.configure(Object, Properties), where Object - new value of parameter
4. Using etjReference, parse Java class to JSON: etjReference.process(Object, int), where int is scanning depth.

Example:

JSONObject json = ETJUtility.create(new POJOAdapter())
				.process(zoo, 0);

Annotations

You can use annotations:

• @ETJMethod(name) This annotation marks method as compulsory for parsing into JSON. 'name' - Key in JSON. By default, it's the name of the method.
• @ETJField This annotation marks the field as compulsory for parsing, if this field is extraneous or has another blocking modification.
• @ShortInfo(name, getter) Annotation ShortInfo used as a pointer to getter, which can provide short info about this object. It's using when current scanning depth equals 0, but we have to provide some information about non-primitive object, stored in the variable of the current scanning object. If this annotation isn't setted, parser will use value of toString().
  1. 'name' - Key in JSON, By default, it's the name of the method.
  2. 'getter' - Getter of short info, necessary. Examples: "getId", "getName"

Properties of ETJReference

These properties operate only within this object of ETJReference.

• WHITELIST_OF_CLASSES, BLACKLIST_OF_CLASSES
  This properties can be used, when you need to parse only several classes from request. Whitelist allows only several classes to be parsed, blacklist prevents some classes to be parsed. Do not use both of them simultaneously!

  Example:

  etjReference.configure(Employee.class, ETJReference.Properties.BLACKLIST_OF_CLASSES);
  

• WHITELIST_OF_METHODS, BLACKLIST_OF_METHODS
  Sounds and works like previous properties, but for methods (getters too). This list is unique for every class, and when it doesn't set up for a specific class, parsing will be as always. Do not use both of them for same class simultaneously!

  Example:

  etjReference.configure("subject.Aviary.getEmployees", ETJReference.Properties.BLACKLIST_OF_METHODS);
  

• SHORT_ONLY_SET
  Classes in this list will be parsed shortly, i.e. only short info will be included in final JSON. Short info - also identification info - briefly characterizes the object. For example, it could be primary key in a database.

  Example:

  etjReference.configure(Employee.class, ETJReference.Properties.SHORT_ONLY_SET);
  

• ALLOW_DUPLICATES, ALLOW_DUPLICATES_IN, ALLOW_DUPLICATES_OF
  The utility can detect duplicates and prevent them to parse fully, leaving only short info. However, in some cases, you probably want to parse these objects. You can do this in three ways:

  • Set ALLOW_DUPLICATES to true. Duplication will be allowed everywhere (for this etjReference, of course).
    Example:

  etjReference.configure(true, ETJReference.Properties.ALLOW_DUPLICATES);
  

  • Add class to ALLOW_DUPLICATES_IN, if duplicates are needed only in this class.
  • Add class to ALLOW_DUPLICATES_OF, if you need to allow duplicates for only specific classes.

• ADDITIONAL_METHODS
  The utility parses primarily pairs "field - getter of field". If you need to attach value from other function, you can use @ETJMethod(name), or use ADDITIONAL_METHODS property. Value of the property is AdditionalMethodSetting object, check javadoc for constructors.

  Example:

  JSONObject json = ETJUtility.create(new POJOAdapter())
  				.configure(new AdditionalMethodSetting("subject.Employee.getFullName", "trigger"), 
  						ETJReference.Properties.ADDITIONAL_METHODS)
  				.process(employee);
  

• PARSE_EMPTY_VALUES, PARSE_EMPTY_VALUES_IN
  When utility stumbles on value null or empty collections, they don't appear in JSON. However, if you need these keys with null values in JSON, you can:

  • Set PARSE_EMPTY_VALUES to true, and this will change behavior everywhere (for this etjReference, of course).
  • Add class to PARSE_EMPTY_VALUES_IN, and changes will affect only specific classes.

  This properties will forward empty collections to JSON, in other cases leave null.

• SCANNING_DEPTH This property replaces default value of scanningDepth. It affects only process(Object).

  Example:

  ETJReference etjReference = ETJUtility.create(new POJOAdapter())
  				.configure(2, ETJReference.Properties.SCANNING_DEPTH);
  JSONObject json1 = etjReference.process(aviary1);
  JSONObject json2 = etjReference.process(aviary2);
  

• INCLUDE_TRANSIENT_FIELDS, INCLUDE_TRANSIENT_FIELDS_IN
  Properties activates the parsing of transient fields. Transient field means that this field doesn't provide necessary information and it can be skipped in final JSON. It can be a local variable, using for in-session calculations, buffer, input-output stream, etc. It depends on Adapter. For JPAAdapter, it is fields with @Transient annotation. If you need them, you can:

  • Set INCLUDE_TRANSIENT_FIELDS to true and this will change behavior everywhere (for this etjReference, of course).
  • Add class to INCLUDE_TRANSIENT_FIELDS_IN, and changes will affect only specific classes.

• INCLUDE_EXTRANEOUS_FIELDS, INCLUDE_EXTRANEOUS_FIELDS_IN
  Properties activates the parsing of extraneous fields. Extraneous field doesn't hold information about their purpose. It can be service information, java internal classes. It depends on Adapter. If you need extraneous fields, you can:

  • Set INCLUDE_EXTRANEOUS_FIELDS to true and this will change behavior everywhere (for this etjReference, of course).
  • Add class to INCLUDE_EXTRANEOUS_FIELDS_IN, and changes will affect only specific classes.