java - How to cut/copy text in JPasswordField as char array? -

how cut/copy password in jpasswordfield clipboard using non-string api. thereby closing window hacker see password.

according link https://stackoverflow.com/a/8885343/2534090 char array different text.

public static void main(string[] args) {     object pw = "password";     system.out.println("string: " + pw);      pw = "password".tochararray();     system.out.println("array: " + pw); } 

prints:

string: password array: [c@5829428e 

what want in clipboard [c@5829428e not password

i tried using stringselection copy contents in clipboard it's constructor takes string immutable , not safe.

you can use custom transferhandler this.

according section swing tutorial on using , creating data flavor should able use char[] object written clipboard.

however, couldn't working , ended writing stringbuilder clipboard. commented out code attempted use char[], maybe else can figure out did wrong.

import java.awt.*; import java.awt.datatransfer.*; import java.awt.event.*; import javax.swing.*; import javax.swing.text.*; import java.io.*;  public class passwordhandler extends transferhandler { //  public final static dataflavor char_array_flavor = new dataflavor(char[].class, "char array");     public final static dataflavor char_array_flavor = new dataflavor(stringbuilder.class, "stringbuilder");      @override     public int getsourceactions(jcomponent c)     {         return copy;     }      @override     public transferable createtransferable(final jcomponent c)     {         return new transferable()         {             @override             public object gettransferdata(dataflavor flavor)             {                 jpasswordfield textfield = (jpasswordfield)c; //              return textfield.getpassword();                 return new stringbuilder( textfield.gettext() );             }              @override             public dataflavor[] gettransferdataflavors()             {                 dataflavor[] flavors = new dataflavor[1];                 flavors[0] = char_array_flavor;                 return flavors;             }              @override             public boolean isdataflavorsupported(dataflavor flavor)             {                 return flavor.equals(char_array_flavor);             }         };     }      @override     public boolean canimport(transfersupport support)     {         boolean canimport = support.isdataflavorsupported(char_array_flavor);         return canimport;     }      @override     public boolean importdata(transfersupport support)     { //      char[] password;         stringbuilder password;          try         { //          password = (char[])support.gettransferable().gettransferdata(char_array_flavor);             password = (stringbuilder)support.gettransferable().gettransferdata(char_array_flavor);         }         catch (exception e)         {             e.printstacktrace();             return false;         }          jpasswordfield textfield = (jpasswordfield)support.getcomponent();         textfield.settext(password.tostring());         return true;     }      private static void createandshowui()     {         jpasswordfield tf1 = new jpasswordfield(10);         jpasswordfield tf2 = new jpasswordfield(10);          transferhandler handler = new passwordhandler();         tf1.settransferhandler( handler );         tf2.settransferhandler( handler );         tf1.putclientproperty("jpasswordfield.cutcopyallowed",true);         tf2.putclientproperty("jpasswordfield.cutcopyallowed",true);          jframe frame = new jframe("password copy");         frame.setdefaultcloseoperation(jframe.exit_on_close);         frame.add(tf1, borderlayout.west);         frame.add(tf2, borderlayout.east);         frame.add(new jtextfield(), borderlayout.south);         frame.pack();         frame.setlocationbyplatform( true );         frame.setvisible( true );     }      public static void main(string[] args)     {         eventqueue.invokelater(new runnable()         {             public void run()             {                 createandshowui();             }         });     } } 

the code takes entire text password field. if want selected characters need modify gettransferdata() method add selected characters stringbuilder.