Java Articles - Page 171 of 540

The JSON-lib API is a java library to serialize and de-serialize java beans, maps, arrays, and collections in the JSON format. We need to convert a JSON string to a bean by converting a string to JSON object first then convert this to a java bean.Syntaxpublic static Object toBean(JSONObject jsonObject, Class beanClass)In the below program, we can convert a JSON string to a bean.Exampleimport net.sf.json.JSONObject; import net.sf.json.JSONSerializer; public class ConvertJSONStringToBeanTest {    public static void main(String[] args) {       String jsonStr = "{\"firstName\": \"Adithya\", \"lastName\": \"Sai\", \"age\": 30, \"technology\": \"Java\"}";       JSONObject jsonObj = (JSONObject)JSONSerializer.toJSON(jsonStr); // convert String ... Read More

The JSONArray is a sequence of values, the external text is a string enclosed in square brackets with commas separating the values and internal text is an object having get() and opt() methods, we need to access those values by index. The element() method for adding or replacing those values. An array is an object that stores multiple values of the same type. It can hold both primitive types and object references. We can convert a JSON array to array by using the toArray() method of JSONArray class. This method produces an Object[] with the contents of JSONArray.Syntaxpublic Object[] toArray()Exampleimport java.util.Arrays; import net.sf.json.JSONArray; public ... Read More

The @Since annotation can use with the setVersion() method of the GsonBuilder class. This annotation can apply to a field in java class and accepts float as an argument. This argument represents the version number in which the field has serialized. The same can apply to the deserialization process.Syntax@Documented @Retention(value=RUNTIME) @Target(value={FIELD, TYPE}) public @interface SinceExampleimport com.google.gson.annotations.Since; import com.google.gson.Gson; import com.google.gson.GsonBuilder; public class GsonSinceAnnotationTest {    public static void main(String[] args) {       Employee emp = new Employee();       emp.setEmployeeName("Raja Ramesh");       emp.setEmployeeId(125);       emp.setEmployeeTechnology("Java");       emp.setEmploeeAddress("Hyderabad");       System.out.println("Since version ... Read More

The @Until annotation can use with the setVersion() method of the GsonBuilder class. This annotation can apply to a field in java class and accepts float as an argument. This argument represents the version number in which the field has serialized. The @Until annotation can manage the versioning of JSON classes in web-services.Syntax@Documented @Retention(value=RUNTIME) @Target(value={FIELD, TYPE}) public @interface UntilExampleimport com.google.gson.annotations.Until; import com.google.gson.Gson; import com.google.gson.GsonBuilder; public class GsonUntilAnnotationTest {    public static void main(String[] args) {       Employee emp = new Employee();       emp.setEmployeeName("Adithya");       emp.setEmployeeId(115);       emp.setEmployeeTechnology("Python");       emp.setEmploeeAddress("Pune");       ... Read More

The JSONObject class is a collection of name/value pairs (unordered) where the bean is a class with setter and getter methods for its member fields. We can convert a JSON object to a bean using the toBean() method of JSONObject class.Syntaxpublic static Object toBean(JSONObject jsonObject, Class beanClass)Exampleimport net.sf.json.JSONObject; public class ConvertJSONObjToBeanTest {    public static void main(String[] args) {       mployee emp = new Employee("Sai", "Ram", 30, "Bangalore");       JSONObject jsonObj = JSONObject.fromObject(emp);       System.out.println(jsonObj.toString(3)); // pretty print JSON       emp = (Employee)JSONObject.toBean(jsonObj, Employee.class);       System.out.println(emp.toString());    }    // Employee class    public static ... Read More

The JsonConfig class can be used to configure the serialization process. We can use the setJsonPropertyFilter() method of JsonConfig to set the property filter when serializing to JSON. We need to implement a custom PropertyFilter class by overriding the apply() method of the PropertyFilter interface. It returns true if the property will be filtered out or false otherwise.Syntaxpublic void setJsonPropertyFilter(PropertyFilter jsonPropertyFilter)Exampleimport net.sf.json.JSONObject; import net.sf.json.JsonConfig; import net.sf.json.util.PropertyFilter; public class ConvertBeanToJsonExcludeFilterTest {    public static void main(String[] args) {       Student student = new Student("Sai", "Chaitanya", 20, "Hyderabad");       JsonConfig jsonConfig = new JsonConfig();       jsonConfig.setJsonPropertyFilter(new CustomPropertyFilter());       ... Read More

The JSON-lib is a Java library for serializing and de-serializing java beans, maps, arrays, and collections in JSON format. We can convert a bean to XML without type hints using the setTypeHintsEnabled() method of XMLSerializer class, this method sets whether JSON types can be included as attributes. We can pass false as an argument to this method to disable the type hints in XML.Syntaxpublic void setTypeHintsEnabled(boolean typeHintsEnabled)Exampleimport net.sf.json.JSONObject; import net.sf.json.xml.XMLSerializer; public class ConvertBeanToXMLNoHintsTest {    public static void main(String[] args) {       Employee emp = new Employee("Krishna Vamsi", 115, 30, "Java");       JSONObject jsonObj = JSONObject.fromObject(emp);     ... Read More

The net.sf.json.xml.XMLSerializer class is a utility class for transforming JSON to XML. When transforming JSONObject instance to XML, this class can add hints for converting back to JSON. We can use the write() method of XMLSerializer class to write a JSON value into an XML string with UTF-8 encoding and it can return a string representation of a well-formed XML document.Syntaxpublic String write(JSON json)Exampleimport net.sf.json.JSONObject; import net.sf.json.xml.XMLSerializer; public class ConvertBeanToXMLTest {    public static void main(String[] args) {       Student student = new Student("Sai", "Adithya", 25, "Pune");       JSONObject jsonObj = JSONObject.fromObject(student);       System.out.println(jsonObj.toString(3)); //pretty print JSON ... Read More

A Java array is an object which stores multiple variables of the same type, it can hold primitive types and object references whereas JSONArray is an ordered sequence of values. Its external text form is a string wrapped in square brackets with commas separating the values, an internal form is an object having get() and opt() methods for accessing the values by index and element() method for adding or replacing values. In the first step, we can create an Object[] array and pass this parameter as an argument to the toJSON() of JSONSerializer class and typecasting it to get the JSON array.We can convert Object[] array to JSONArray in the below exampleExampleimport ... Read More

The JsonConfig class is a utility class that helps to configure the serialization process. We can convert a bean to a JSON object with few properties that can be excluded using the setExcludes() method of JsonConfig class and pass this JSON config instance to an argument of static method fromObject() of JSONObject.Syntaxpublic void setExcludes(String[] excludes)In the below example, we can convert bean to a JSON object by excluding some of the properties.Exampleimport net.sf.json.JSONObject; import net.sf.json.JsonConfig; public class BeanToJsonExcludeTest {    public static void main(String[] args) {       Student student = new Student("Raja", "Ramesh", 35, "Madhapur");       JsonConfig jsonConfig = new ... Read More