java - Constructing an object from a string -

is possible construct object given string, tostring() method, , class itself.

for example have class book.

class book {    // ...     string gettitle()    {       return title;    }     string getpubyear()    {       return pubyear;    }     void settitle(string _title)    {       title = _title;    }     void setpubyear(string _pubyear)    {       pubyear = _pubyear;    }     public string tostring(){       return title+" "+pubyear;     } } 

if have string:

"exampletitle 2017" 

how can create instance of class book, has attribute:

title=exampletitle  pubyear=2017 

we can following:

book book = new book(); string examplestring = "exampletitle 2017"; string[] parts = examplestring.split(); book.settitle(parts[0]); book.setpubyear(parts[1]); 

but long winded. there more automatic way this?

you can add new constructor:

public book(string s) {     string[] parts = s.split(" ");     if (parts.length() == 1) {         this.title = s;     } else {        this.title=parts[0];        this.pubyear(integer.parseint(parts[1]));     } } 

you should add numberformatexception handling on own recommend post it.

the above constructor take string, split space , perform have done. can use like:

book book = new book("example_title 2001"); 

but it's not best approach. should rather use standard patterns , first extract values want set book , pass them constructor.

the way of doing want make constructor:

public class book {      public book(string s, int y) {         this.title = s;         this.year = y;     } } 

please change year field int or long. year shouldn't string long you're not using roman numbers.