The serialization of objects in the Jackson Library of Java parsing and data generic binding _java

Jackson Object serialization
this will introduce the serialization of Java objects to a JSON file and then the JSON file fetch to the object. In this example, the student class is created. The creation will have the student object represented in JSON in a Student.json file.

Create a Java class file named Jacksontester in C:\>jackson_workspace.

File: Jacksontester.java

Import Java.io.File;

Import java.io.IOException;
Import org.codehaus.jackson.JsonGenerationException;
Import org.codehaus.jackson.JsonParseException;
Import org.codehaus.jackson.map.JsonMappingException;

Import Org.codehaus.jackson.map.ObjectMapper;
   public class Jacksontester {public static void main (String args[]) {Jacksontester tester = new Jacksontester ();
     try {Student Student = new Student ();
     Student.setage (10);
     Student.setname ("Mahesh");

     Tester.writejson (student);
     Student student1 = Tester.readjson ();

   System.out.println (STUDENT1);
   catch (Jsonparseexception e) {e.printstacktrace ();
   catch (Jsonmappingexception e) {e.printstacktrace ();
   catch (IOException e) {e.printstacktrace (); } private void Writejson (Student Student) throws Jsongenerationexception, Jsonmappingexception, ioexception{OBJ 
   Ectmapper mapper = new Objectmapper ();
  Mapper.writevalue (New File ("Student.json"), student); } priVate Student Readjson () throws Jsonparseexception, Jsonmappingexception, ioexception{objectmapper mapper = new OBJECTM
   Apper ();
   Student Student = Mapper.readvalue (New File ("Student.json"), Student.class);
  return student;
  } class Student {private String name;
  private int age;
  Public Student () {} public String GetName () {return name;
  public void SetName (String name) {this.name = name;
  public int getage () {return age;
  public void Setage (int age) {this.age = age;
  Public String toString () {return ' Student [name: ' +name+ ', Age: ' + age+ '] ';

 } 
}

Validation results

Use Javac to compile the following classes:

Copy Code code as follows:

C:\jackson_workspace>javac Jacksontester.java

Now run Jacksontester See the results:

Copy Code code as follows:

C:\jackson_workspace>java Jacksontester

Verifying output results

Copy Code code as follows:

Student [Name:mahesh, Age:10]

Jackson Data-binding generics
In simple data binding, we use string as the key object and map the class as a value object. Instead, we can use specific Java objects and types to cast to JSON.

Consider the following example to use the UserData of a class to save user-specific data.

Create a c:\>jackson_workspace named Jacksontester in the Java class file directory.

FileName: Jacksontester.java

Import Java.io.File;
Import java.io.IOException;
Import Java.util.Arrays;
Import Java.util.HashMap;
Import java.util.List;

Import Java.util.Map;
Import org.codehaus.jackson.JsonGenerationException;
Import org.codehaus.jackson.JsonParseException;
Import org.codehaus.jackson.map.JsonMappingException;
Import Org.codehaus.jackson.map.ObjectMapper;

Import org.codehaus.jackson.type.TypeReference;
     public class Jacksontester {public static void main (String args[]) {Jacksontester tester = new Jacksontester ();

      try {objectmapper mapper = new Objectmapper ();
      Map Userdatamap = new HashMap (); 
      UserData studentdata = new UserData ();

      Int[] marks = {1,2,3};
      Student Student = new Student ();
      Student.setage (10);
      Student.setname ("Mahesh");
      JAVA Object studentdata.setstudent (student);
      JAVA String studentdata.setname ("Mahesh Kumar");
      JAVA Boolean studentdata.setverified (boolean.false);
     Array Studentdata.setmarks (marks);
      TypeReference ref = new Typereference> () {};
      Userdatamap.put ("StudentData1", studentdata);
      Mapper.writevalue (New File ("Student.json"), Userdatamap);
      {//"STUDENTDATA1"://{//"student"://{//"name": "Mahesh",//"Age": 10
      },//"name": "Mahesh Kumar",//"verified": false,//"Marks": [1,2,3]//}//}

      Userdatamap = Mapper.readvalue (New File ("Student.json"), ref);
      System.out.println (Userdatamap.get ("StudentData1"). Getstudent ());
      System.out.println (Userdatamap.get ("StudentData1"). GetName ());
      System.out.println (Userdatamap.get ("StudentData1"). Getverified ());
   System.out.println (Arrays.tostring (Userdatamap.get ("StudentData1"). Getmarks ());
   catch (Jsonparseexception e) {e.printstacktrace ();
   catch (Jsonmappingexception e) {e.printstacktrace (); catch (IOException e) {E.printstacktrace();
  }} class Student {private String name;
  private int age;
  Public Student () {} public String GetName () {return name;
  public void SetName (String name) {this.name = name;
  public int getage () {return age;
  public void Setage (int age) {this.age = age;
  Public String toString () {return ' Student [name: ' +name+ ', Age: ' + age+ '] ';
  } class UserData {private Student Student;
  private String name;
  Private Boolean verified;

  Private int[] marks;
  Public UserData () {} public Student getstudent () {return Student;
  public void Setstudent (Student Student) {this.student = Student;
  Public String GetName () {return name;
  public void SetName (String name) {this.name = name;
  Public Boolean getverified () {return verified;
  } public void setverified (Boolean verified) {this.verified = verified;
  Int[] Getmarks () {return marks;
} public void Setmarks (int[] marks) {   This.marks = marks;

 } 
}

Validating output

Use Javac to compile the following classes:

Copy Code code as follows:

C:\jackson_workspace>javac Jacksontester.java

Now run Jacksontester See the results:

Copy Code code as follows:

C:\jackson_workspace>java Jacksontester

Validating output

Student [Name:mahesh, Age:10]
mahesh Kumar
false
[1, 2, 3]