Why the method clone() in object class as a "protected"?

Similar Questions

• Why the method in the several times called session bean

  Hello
  I work with Jdev 11 g.
  I created an example Web J2ee Application.
  In the model project, I created:
  1 - entity Bean
  2 - stateless session bean (which contains a method that get the list of username == > em.createNamedQuery("OsaUser.findAll").getResultList ();)
  
  In the view controller project I created:
  1 - managed bean, session scope, a getter that calls the session bean and retrieve the result of the query.
  2 - a JSF page with af:table element with the value bound to the list in the managed bean.
  
  When I run the application, the data is displayed, but since I put system.out message I get this message several times.
  When I try to debug the application the breakpoints on the managed bean and session bean are available several times.
  
  Can you please advice why this happens.
  Concerning
  Emile BITAR

  Hello

  partially, it's the cycle of life and partially a known bug. The method is called during ApplyRequest and RenderResponse. If you check this in your output, so you see that make answer calls at least three times, which is the bug that we set. As a temporary work around, set a flag within the scope of the request (since your bean's scope of session that you use a requestScope attribute). The first time you run, you set the attribute flag. So every time its called again, you check to see if the indicator exists and if ignore the request. Because the flag is set to request scope, you needn't clean it explicitly

  Frank

• What are all the myths around method clone() interface Cloneable?

  There were other similar to this questions: why is - #clone () not in the Cloneable interface? and others.
  
  But this is not the same or duplicate. It tries to go in the logical aspects of what harm would happen if something else this would have been done.
  
  Interface Cloneable why question 1) in the first place?
  
  Question (2) why is Cloneable interface interface marker or why not keep method clone() in there?
  
  Question 3) why not create a Cloneable class rather than the recognizable interface?
  
  Question 4) why it's default implementation of the method in object clone()?
  
  Question 5) why so method clone() protected object?

  nitul.kukadia wrote:
  There were other similar to this questions: why is - #clone () not in the Cloneable interface? and others.

  But this is not the same or duplicate. It tries to go in the logical aspects of what harm would happen if something else this would have been done.

  Interface Cloneable why question 1) in the first place?

  Who cares why? What is important is that it is like that, and he won't change. Only people who have designed, it can really answer. That was over 15 years ago. I'm sure if you asked these people in an interview today they would answer Yes, "I would differently today.

  Question (2) why is Cloneable interface interface marker or why not keep method clone() in there?

  No need; all objects inherit from the object and the object has the clone() method.

  Question 3) why not create a Cloneable class rather than the recognizable interface?

  Because you can extend only one class and implement several interfaces. What makes a class would severely limit you. What actually a class wouldn't change anything anyway - it would be always empty.

  Question 4) why it's default implementation of the method in object clone()?

  Convenience? Basically the same as 1), why can only really be answered by the people who designed it.

  Question 5) why so method clone() protected object?

  Once again a why. Because a group of people decided that should be the case.

  My own point of view on this, is that it is a compromise between adhering to an interface contract (Cloneable) while providing a default implementation anyway (Object.clone ()). But I can only guess. I do not why in all cases, I only care how to do it correctly. Which is pretty easy and well documented.

• [ADF, JDev12.1.3] Why AM method cannot be exposed to the client if it does not return a simple type or serializable? How...?

  Hallo,

  I would like to know why the methods that I create in the request Module cannot be exposed to the client if they return a simple type or serializable.

  If the method returns a custom class object I solve the problem by simply writing next to the defining class "implements Serializable.

  I would like to know if it's still OK, or for a custom class with some features I really need to implement the serialization (de).

  Thank you

  Federico

  Return values must be serializable nexus him must be transported between servers and memory a store if your module gets passive

  Is normally enough tto implement the serializable interface. But in doing so you do not make the class serializable automatically. To do this, you must check if each attribute or class variable is serialized or to be transitory if they are not serialize the value.

  Timo

• With the help of several classes and create an object of a class and calling its method in a different class.

  Creating a new class, I need to move my main method class SaveDate DynamicTest class. Below I've listed the code of both classes. The goal is to be able to run my class DynamicTest program. I need help to understand the process of moving my main method of a different class and creating an object of a class and calling its method.

  public class {SaveData

  private public static final map < String, Object > myCachedTreeMap = new TreeMap < String, Object > ();

  public static final List < String > getLines (final String resourceParam, final Charset charset) throws IOException {}

  System.out.println ("please:" + resourceParam);

  If {(myCachedTreeMap.containsKey (resourceParam))

  Use the file cached, to avoid a further reading.

  System.out.println ("found in memory:" + resourceParam);

  }

  else {}

  Load the file from the disk

  System.out.println ("found in memory:" + resourceParam);

  }

  Returns a null value.

  }

  Public Shared Sub main (String [] args) throws IOException {}

  String target_dir = "C:\\myfiles\\config\\en";

  Line = "C:\\myfiles\\config\\en\\output.txt";

  File dir = new File (target_dir);

  File files [] = dir.listFiles ();

  If (file == null: files.length < 1) {}

  System.out.println ("file list is empty...");

  return;

  }

  Open the Printwriter

  PrintWriter OutputStream = new PrintWriter (output);

  try {}

  for (textFile file: files) {}

  If (textFile.isFile () & & textFile.getName () .endsWith (".txt")) {}

  readFromDisk (textFile);

  }

  }

  }

  {Finally

  outputStream.close ();

  }

  String fileNameFromCache = "en_synonyms.txt";

  Sheet1 = myCachedTreeMap.get (fileNameFromCache) object;

  System.out.println (fileNameFromCache + ": \n" + "Sheet1");

  }

  @SuppressWarnings ("resource")

  private static Sub readFromDisk(File textFile) throws FileNotFoundException, IOException {}

  BufferedReader InputStream;

  inputStream = null;

  String content = "";

  try {}

  inputStream = new BufferedReader (new FileReader (textFile));

  content = readFile (textFile);

  System.out.println ("bytes read =" + content.length ());

  Save the content

  FileContentsObject Sheet1 = new FileContentsObject (System.currentTimeMillis (),

  textFile.lastModified (), content,

  textFile.getName (),

  getLines (null, null));

  Add to the map

  myCachedTreeMap.put (textFile.getName (), Sheet1);

  }

  {Finally

  If (inputStream! = null) {}

  inputStream.close ();

  }

  }

  }

  private static String readFile(File f) throws FileNotFoundException, IOException, UnsupportedEncodingException {}

  Text of StringBuilder = new StringBuilder (1024);

  read int, N = 1024 * 1024;

  char [] buffer = new char [N];

  BufferedReader br = null;

  try {}

  BR = new BufferedReader)

  (new) InputStreamReader

  (new FileInputStream (f), 'UTF8'));

  While (true) {}

  read = br.read (buffer, 0, N);

  If (read > 0)

  Text.Append (new String (buffer, 0, read));

  if(Read < N) {}

  break;

  }

  }

  }

  {Finally

  If (br! = null)

  Br. Close();

  }

  Return text.toString ();

  }

  private static final class FileContentsObject {}

  private long cachedTime; currentTime

  private long lastModifiedTimestamp;

  private string content

  List < String > lines;

  private String fileName;

  public FileContentsObject (long cachedTime, long lastModifiedTimestamp,

  Content string, String fileName, List < String > lines) {}

  this.cachedTime = cachedTime;

  this.lastModifiedTimestamp = lastModifiedTimestamp;

  This.contents = content;

  this.fileName = filename;

  This.Lines = lines;

  SimpleDateFormat sdf = new SimpleDateFormat ("MM/dd/yy hh: mm :"); ")

  System.out.println ("time & Date:" + sdf.format (cachedTime));

  System.out.println ("' last modification timestamp:" ")

  + sdf.format (lastModifiedTimestamp));

  }

  /**

  *

  * @return the lines of the file

  */

  List < String > getLines() {}

  Return this.lines;

  }

  public String toString() {}

  "return"Sheet1 {}"+" fileName =' ' + filename + '------"+", content = "" "

  + content + "\"+ ", lastModifiedTimestamp ="

  + lastModifiedTimestamp + ', CurrentTime & Date ='

  {+ cachedTime + '}';

  }

  }

  }

  ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

  public class DynamicTest {}

  Public Shared Sub main (String [] args) {}

  Game characters charset = Charset.forName("UTF-8");

  try {}

  List < String > = CacheData.getLines lines ("en_synonyms", character set);

  If (rows! = null) {}

  System.out.println ("number of rows:" + lines.size ());

  for {(String ligne: lines)}

  System.out.println ("DynamicTest:" + line);

  }

  }

  } catch (IOException e) {}

  e.printStackTrace ();

  }

  try {}

  List < String > = CacheData.getLines lines ("en_stopwords", character set);

  If (rows! = null) {}

  System.out.println ("number of rows:" + lines.size ());

  for {(String ligne: lines)}

  System.out.println ("DynamicTest:" + line);

  }

  }

  } catch (IOException e) {}

  e.printStackTrace ();

  }

  }

  }

  I have read and watched videos about the creation of an object of a class and calling its method in a different class. I'm still confused on how to do it properly. By using the code below if someone can explain how to properly call the method of objects from my hand.

  Huh? You have NOT posted any 'hand' or any 'method of objects '.

  If you need help with the code, you need to view the code.

  The Java tutorials has dozens of trails "Classes and objects": what they are, how to create and how to use them.

  https://docs.Oracle.com/javase/tutorial/Java/javaOO/classes.html

  1. create an instance of a class

  2. call to one or more of the public methods of this class

  If the class has public static methods, you don't need to create an instance first.

  I suggest that you work your way through these tutorials. They include the WORKING example code.

• Access the method of class (impl) view of bean object (or vice versa)

  Halo everybody, I use JDeveloper 11.1.2.1.0
  
  I use a UsersViewImpl class with a method that update the table as below.
  
  public void resetEmployeeSearch() {}
  removeApplyViewCriteriaName ("viewCriteria");
  executeQuery();
  }
  
  and I have a UserBean class with a method that reset the values of fields of research such as below.
  
  {} public void resetInput (ActionEvent actionEvent)
  ........ RichInputText = entry...
  input.setValue("");
  AdfFacesContext.getCurrentInstance () .addPartialTarget (searchForm);
  ........
  }
  
  
  I want to implement that, once I press a button, the two methods are called.
  
  I tried to call method of bean using vs UsersViewImpl = new UsersViewImpl... who does not and will not work.
  I've read about something as ViewObject vo = am.findViewObject ("DeptView1") but I duno how to use because I can't have a good example.
  
  Any suggestion on access to the method of class (impl) view of bean object (or vice versa)?
  Or is it possible to combine the two method in the same class?
  
  
  Thanks :(

  and then create a link to this effect in your page. > Sorry, dun get this part. You create the link from the button to the UsersViewImpl method?
  The code below should be method (binding) in UsersViewImpl, right?
  OperationBinding op = ((DCBindingContainer) BindingContext.getCurrent () .getCurrentBindingsEntry ()) .getOperationBinding ();
  op. Execute();

  What I meant to say call this code your method of bean... this way you can call both the logic in your bean and the method of VO together!

• reading viewScope variable in the method of the ViewImpl class

  Hello
  
  Suppose I want to get viewScope.deptno in my function that is declared in the class ViewImpl
  
  ' Public Sub proc (String deptno, String amount) {}
  setp_deptno (deptno == null? ('%': deptno);
  this.setNamedWhereClauseParam ("p_deptno", deptno);
  this.executeQuery ();
  System.out.println("viewScope.DEPTNO="...?);
  }
  
  How to get to it in my service?

  do you mean placing the logics from VOImpl to client interface class?
  

  Yes, then you can see the method exposed in the control of data under the node ViewObject. Then, you can run the method in your method of beans as below

      public String executeMyVOMethod {
          BindingContainer bindings = getBindings();
          OperationBinding operationBinding = bindings.getOperationBinding("proc");
          operationBinding.getParamsMap().put("deptno", PassAnyDeptNo);//you can get it from view scop variable
          operationBinding.getParamsMap().put("amount", passAnyAmmountvalue);  //you can get it from view scop variable
          Object result = operationBinding.execute();
          if (!operationBinding.getErrors().isEmpty()) {
              return null;
          }
          return null;
      }
  

  could you clarify why this is a bad practice to store the logic in VOImpl?
  is it because I can't refer to ViewScope of there?
  >

  access a range of memory variable in your model layer (if its there) is a bad practice, because you're breaking MVC model. This is not the best approach, even if you can do it.

  >
  (this approach is based on video tutorial of Shay "Passing parameters to the ADF through the URL of the Application")
  >
  It's different, it's not your use case

• To access the methods of the VORowImpl class

  Scenario is,

  I have a view object class VOImpl.java in the model.view package.

  I have another class of JavaBean EntryHandle.java

  EntryHandle class I can Import model.view.VOImpl;

  Help me now how I can access methods of the VOImpl class in the ADF.

  Or I have to create the VOImpl object class in class EntryHandle? as in programming java Simple? or something else

  JDeveloper Version: 11g Release 2 11.1.2.0.0

  Zaid,

  If you have a VO with 2 attributes, you have defined the category value. (This poster Lov sense and sets the value for the category field).

  You want to get the value selected from the lov. Is this correct?

  When do you get this value? When they choose a new value from the LOV.

  If you have written the code in the valueChangeListener, you can check the link below:

  https://blogs.Oracle.com/ADF/entry/getting_selected_value_from_selectonechoice

  Code of the blog

  public void valueChanged(ValueChangeEvent valueChangeEvent) {
      this.setValueToEL("#{bindings.Deptno.inputValue}", valueChangeEvent.getNewValue()); //Updates the model
      System.out.println("\n******** Selected Value: "+resolveExpression("#{bindings.Deptno.attributeValue}"));
      System.out.println("\n******** Display Value: "+resolveExpression("#{bindings.Deptno.selectedValue ne ' ' ? bindings.Deptno.selectedValue.attributeValues[1] : ''}"));
  }
  
  public Object resolveExpression(String el) {
      FacesContext facesContext = FacesContext.getCurrentInstance();
      ELContext elContext = facesContext.getELContext();
      ExpressionFactory expressionFactory =  facesContext.getApplication().getExpressionFactory();
      ValueExpression valueExp = expressionFactory.createValueExpression(elContext,el,Object.class);
      return valueExp.getValue(elContext);
  }
  
  public void setValueToEL(String el, Object val) {
      FacesContext facesContext = FacesContext.getCurrentInstance();
      ELContext elContext = facesContext.getELContext();
      ExpressionFactory expressionFactory =   facesContext.getApplication().getExpressionFactory();
      ValueExpression exp = expressionFactory.createValueExpression(elContext, el, Object.class);
      exp.setValue(elContext, val);
  }
  

  You can get the selected value and the value of display with the above code. You need to replace Deptno by category.

  See you soon

  AJ

• What is the method of the String class's trim() in special cases?

  You are looking for here ( String (Java Platform SE 7) ), I understand that the method of the String class's trim() 'returns a copy of the string with white spaces of early and omitted end', but I don't understand what the last special case Unicode characters is exactly.

  You are looking for here ( list of characters Unicode - Wikipedia, the free encyclopedia ), I see that U + 0020 is a space character, and I also see the characters that follow the character space (for example, the exclamation point character).

  So, I decided to write a sample of the size of the code to try to reproduce the behavior that I quoted (from the documentation of the API of the trim method) in the comment from several line of this code even example. Here is the code example. :

  public class TrimTester {
  
      public static void main(String[] args) {
         
          /*
           * "Otherwise, let k be the index of the first character in the string whose code
           * is greater than '\u0020', and let m be the index of the last character in the
           * string whose code is greater than '\u0020'. A new String object is created,
           * representing the substring of this string that begins with the character at
           * index k and ends with the character at index m-that is, the result of
           * this.substring(k, m+1)."
           */
          String str = "aa!Hello$bb";
          System.out.println(str.trim());
      }
  }
  

  However, what is printed is "aa." «Hello bb$ "(without the quotes) instead of «!» "Hello$" (without the quotes).

  Any input to help me better understand what's happening would be greatly appreciated!

  Hallo,

  I think that the characters 'a' and 'b' both have greater than '\u0020' code, so your entire string is returned by the trim () - method, then the first character of the string whose code is superior to ' \u0020 has index 0, and the last character whose code is greater than '\u0020' a index 10. All printable characters have codes greater than 0020, try "\r\ntest". After trim(), you get 'test '.

  Regarding

  Rafal Z

• By comparing the dynamic fields of objects using equals and hashCode methods

  To compare the different objects of the same class with their content as jobTitleId, classificationId, deptId & classificationId had to be done and do a few steps later, using Set and the map. I was able to do it by simple substitution of equals and hashCode methods of the object class and was able to read the information (as in the map below).

  Map < LocationData, list < LocationData > >

  The following is the class I used (its been shown you so that it can be called for my problem statement):

  Class LocationData

  package com.astreait.bulkloader;

  public class LocationData {}

  String locId, deptId, jobTitleId, classificationId;

  @Override

  public boolean equals (Object obj) {}

  LocationData ld = (LocationData) obj;

  return this.deptId.equals (ld.deptId) & & this.jobTitleId.equals (ld.jobTitleId) & & this.classificationId.equals (ld.classificationId) & &

  this.locId.equals (ld.locId);

  }

  @Override

  public int hashCode() {}

  return deptId.hashCode () + jobTitleId.hashCode () + classificationId.hashCode () + locId.hashCode ();

  }

  }

  Problem:

  I am already known to which all the fields of this object, I need to make the comparison.

  IE I have to use the variables named classificationId, deptId, jobTitleId & locId etc.

  Need:

  I need to customize this logic such as names (classificationId, deptId, jobTitleId & locId etc.) fields can be learned, dynamically, as well as their values. So, as far as I understand, I've made use of 2 classes (TableClass and ColWithData), such as the list of the ColWithData is there in the TableClass object.

  I think what will happen if I substitute the same two methods "equals() and hashCode();"

  as the same thing is possible.

  TableClass class #1

  Class TableClass {}

  The list < ColWithData > cwdList;

  @Override

  public boolean equals (Object obj) {}

  Return Boolean = false;

  I need to have the logic must be set such that

  all dynamic fields can be compared

  return return;

  }

  @Override

  public int hashCode() {}

  Return int = 0;

  I need to have the logic must be set such that

  All dynamic fields for their individual codes can be found

  return return;

  }

  }

  ColWithData class #2

  Class ColWithData {}

  Pass the string; Here, the jobTitleId, classificationId, deptId, locId or any other information fields more may come.

  String data; The corresponding data or value for each jobTitleId, classificationId, deptId, locId or any other more fields.

  }

  Please let me know if I'm the procedure in the right direction or should I do a different approach. If it is allowed to use the current approach then what should be done to equals and hashCode methods?

  Finally, I need to make the map as: (is not worried how I give you, but may be considered my goal sought this logic)

  Map < TableClass, list < TableClass > > finalMap;

  I'm sorry for that. Although the problem is resolved, on my side.

• Call the method of the object, the view object entity

  Hi all
  I use jdeveloper 11.2.1.0, and I need to call the method in the object class to view object entity class.
  Someone knows how to do?
  
  Thank you.

  http://andrejusb.blogspot.in/2009/11/calling-custom-entity-method-from-view.html

• Actual mechanism of object class as the superclass for all classes

  Hi all
  
  We know that all the classes of the java platform are the descendants of the object class. Even if we write a new class, in the absence of any explicit superclass, each class is implicitly a subclass of the object. As we expand it, not directly the object class, then how is the methods of the object are inherited from the class Sub that we wrote? How the java to maintain this hierarchy?
  
  Can you please explain this carefully?
  
  Thanks in advance,
  Uday

  Udaya Shankara Gandhi wrote:
  Hi all

  We know that all the classes of the java platform are the descendants of the object class. Even if we write a new class, in the absence of any explicit superclass, each class is implicitly a subclass of the object. As we expand it, not directly the object class, then how is the methods of the object are inherited from the class Sub that we wrote? How the java to maintain this hierarchy?

  Because the language is defined in this way. Compilers implement the language according to the rules of the DG JLS. Exactly how they do it is not defined. It is each compiler. As long as it respects the rules defined in the JLS to the code analysis and generate the .class file, that's all that matters. However, somewhere in the compiler's code which is about:

  if (class has an extends clause) {
    generate corresponding bytes for extends in .class file
  }
  else {
    generate bytes for extends java.lang.Object in .class file
  }
  

  No great mystery, or philosophical question.

• How to access the methods and properties of the main document class

  How can I access methods and properties of the class of main document of other classes?
  Can someone give me a clue what I'm doing wrong?
  
  I use ActionScript3 in Flash CS3 with strict error checking on. I have an application with several custom classes:
  
  1. the MainMovie class is associated with the document.
  
  2. the SomeMovieClip class is associated with a movie clip symbol in the library and an instance of the symbol is placed on the main timeline.
  
  Compilation Flash returns this error message: "1061: call to a method may not set [name of the method here] through a reference with static type flash.display:DisplayObject.".
  
  I get the same error if I replace the undelined above with this code:
  
  root.gotoAndStop ("aFrameLabel");
  
  
  If I replace the same code simply with:
  
  trace (root)
  
  Flash returns [object MainMovie], which tells me that it recognizes the document class.
  
  However, if I turn the strict error checking, the compilation ends and the movie works as expected in all cases.
  
  

  root cast as a movieclip.

• When I do an email upward on outlook express 4, using the method described in Q270670 it backup my spam email. Why?

  Email backup - anti spam files

  When I do an email upward on outlook express 4 by using the method described in Q270670 I found the file was a massive file. On the investigation, I found that the file contained thousands of files for anti-spam (ca. 6 GB). These fact files does not appear in outlook express in the anti-spam file but only appear in the backup download. It is probably an accumulation of messages anti-spam for 6 years.

  Why is this?

  I can't open the dbx files to see what is in them

  Your comments / tips

  According to Bruce, EO4 served in Win95 and Win98.  The steps you describe in this article concern OE6, then maybe that's what you mean.

  There is no 'anti-spam' files in OE, according to Bruce, and so if you have 6 gigabytes, then it is likely those are the dbx files that contain messages.  See www.oehelp.com/OETips.aspx#6 for OE data backup.  If you use some kind of anti-spam with OE program, then see point 3 on this page, contact the anti-spam software provider and ask them to explain it.

  Steve

• Question about rom 9900, override the method object failed

  Before I update the ROM (9900jAllLang_PBr7.1.0_rel2435_PL5.1.0.622_A7.1.0.862_AT_T.exe) for my 9900, I can easily overrides the method of object to change text styles or field label, for example the size of the font, color of the text and so on.

  But, after update, I can always control the color of text, except the font size!

  I can make sure my codes worked properly 'before', I think this must be a problem of system because all my apps cannot resize the font size more!

  Is there any other way to solve this problem? I need your help, thank you! ~

  Code looks OK, but I would like you to try something.  Can you please set the font for the LabelField rather than change the paint of duing fonts.  Then change this:

  LabelField = about new LabelField ("about aid and", USE_ALL_WIDTH |) LabelField.ELLIPSIS) {}
  public void paint (Graphics g)
  {
  g.setFont (Font.getDefault () .derive (Font.BOLD, Font.getDefault () .getHeight (Ui.UNITS_pt) + 2, Ui.UNITS_pt));
  Super.Paint (g);
  }
  };

  to something like this:

  LabelField = about new LabelField ("about aid and", USE_ALL_WIDTH |) LabelField.ELLIPSIS);

  about.setFont (Font.getDefault () .derive (Font.BOLD, Font.getDefault () .getHeight (Ui.UNITS_pt) + 2, Ui.UNITS_pt);)