using java 1) using stringbuffer class in this method, we use reverse() method of stringbuffer class to reverse the string. here is the code snippet to reverse the string using reverse() method of stringbuffer class. 2) using iterative methodin this method, first we convert given string to char array using chararray() method. and then we … ,annotation @jsoninclude of jackson library which helps in eliminating default, null, empty, etc values. for this post, we will focus on default values. suppose we have an employee pojo as below:- it may not be mandatory to pass values to all fields in a payload. for example, a “gender” field may be optional and you … ,class objectmapper this is the most powerful class provided by jackson api and maximum time we will use this class. objectmapper class is useful to create json object, json array, converting a java object to a json object and vice versa. in this post, we will use the objectmapper class to convert a java object … ,now we will learn how to create json objects using pojos. to create a json object (json) from java objects( pojos) is called serialization. for this, we can use any json parser apis. in this post, we will use jackosn apis about jackson api jackson api is a high-performance json processor for java. we can … ,example json payload creating pojo classes are simple if we identify what are classes we need to create correctly. a final pojo class for a json payload is created by combining multiple blocks. let’s identify different objects or pojo :- there is no need to create a pojo for a 1:1 fields. we can include … ,sample json array payload above json array is a collection of json objects or a list of employees. we have created a employee pojo class in previous post and we can reuse the same. that is how reusability is one of the major advantage of pojo classes. employee pojo we do not need any other … ,pojo classes are extensively used for creating json and xml payloads for api. although there are many online platform to generate pojo and java libraries to generate pojo classes automatically but still knowing to create pojo helps. even you can use plain pojo concepts or pojo with builder pattern for data storage as well which … ,java supports object oriented programming system (oops) which is a programming paradigm. from the full form of oops , we can understand that it is a programming approach which is oriented around something called “object” and an object can contain data (member variables ) and mechanism (member functions) to manipulate on these data. for an … ,we have already learnt to create json object using jackson api if you download and add jackson-databind jar to build path, do not forget to download other two transitive dependencies as well. class objectmapper this is the most powerful class provided by jackson api and maximum time we will use this class. as of now …