blocks|key|1603959|text|我想，我为这个问题找到了一个小的解决方案，但使用了另一个概念-只有一个类(和一个接口)；在这个类中，我有一个main方法，它选择了正确的“要打开的方法”；在这个例子中，我通过int进行检查：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1603960|/|1603961|MenuBar+menu+=+new+MenuBar(true);

++++for+(int+k+=+0;+k+<+5;+k%2B%2B)+{
++++++++++++int+ii=k;
++++++++++++menu.addItem(tekst+%2B+k,+new+Command()+{

++++++++++++++++@Override
++++++++++++++++public+void+execute()+{
++++++++++++++++++++ClassMetodInterface+metoda+=+(ClassMetodInterface)+GWT.create(Method2.class);
++++++++++++++++++++vPanel.clear();+//clearing+before+I+open+a+new+widget.

/*I+sent+int+(easier+to+tests),+but+I+can+sent+string[i]+too*/
/*+logging+-+instance+of+main+class+to+communicate+with+'subclasses',+in+my+project+necessery*/

++++++++++++++++++++vPanel.add(metoda.defaultMethod(ii,+logging));++
++++++++++++++++}

++++++++++++});
++++++++}
(...)
/*-------------------------------------------*/
ClassMetodInterface,+only+for+implementation+class+Method2+:
/*-------------------------------------------*/
++++public+interface+ClassMetodInterface+{
++++Widget+defaultMethod(int+g,+Logging+logging);
}

/*-------------------------------------------*/
class+Method2+with+swich:
/*-------------------------------------------*/


public+class+Method2+implements+ClassMetodInterface+{

++++public+Widget+zapisUsera(int+g,+Logging+logging)+{

++++++++Logging+logging;
++++++++HorizontalPanel+lPanel+=+new+HorizontalPanel();

++++++++switch(g)+{
++++++++case+1:+{
++++++++++++Window.alert("switch+for+test+no:"%2Bg);
++++++++++++MenuWindow1(logging);

++++++++++++break;

++++++++}
++++++++case+2:{
++++++++++++Window.alert("switch+for+test+no:"%2Bg);
++++++++++++break;
++++++++}
++++++++default:
++++++++++++Window.alert("switch+default+-+loop+>2+&&+<1");
++++++++++++break;
++++++++}
++++++++return+lPanel;++//all+methods+will+be+void+-+they+will+be+add+widgets+and+Panels+to+lPanel

++++}

++++public+Widget+MenuWindow1(Logging+logging)+{
++++++++this.logging+=+logging;

++++++++lPanel.setBorderWidth(2);
++++++++this.lPanel.setPixelSize(100,+50);+
++++++++Button+b1+=+new+Button("test+button,+not+used");++++
++++++++lPanel.add(b1);

++++++++Label+lbl+=+new+Label("label+no+"%2Blogging.i);+++++++

++++++++lPanel.add(lbl);
++++++++Button+addGlobal+=+new+Button("%2B");
++++++++Button+removeGlobal+=+new+Button("-");
++++++++lPanel.add(addGlobal);
++++++++addGlobal.addClickHandler(new+addGlobal());
++++++++removeGlobal.addClickHandler(new+removeGlobal());
++++++++lPanel.add(removeGlobal);


++++++++return+lPanel;

++++}

//for+tests+communication+with+class,+where+I+have+menu+and+global+variable
++++public+class+addGlobal+implements+ClickHandler+{

++++++++@Override
++++++++public+void+onClick(ClickEvent+event)+{
++++++++++++logging.i%2B%2B;
++++++++}

++++}

++++public+class+removeGlobal+implements+ClickHandler+{

++++++++@Override
++++++++public+void+onClick(ClickEvent+event)+{
++++++++++++logging.i--;
++++++++}

++++}
}|code-block|syntax|javascript|1603962|它还没有完成，但你可以展示主要的想法。如果我需要向菜单添加新的选项，我会更新db，并用更多的方法替换一个版本的类。|1603963|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|N|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|O|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I thing, I found a small solution for this problem, but with another concept - only one class (and one interface); in this class I have one main method, which choose correct 'method to open'; in this example I check by int:

/-------------------------------------------/
Example loop in main part of program:
/-------------------------------------------/
(...)

<pre><code>MenuBar menu = new MenuBar(true);

 for (int k = 0; k &lt; 5; k++) {
 int ii=k;
 menu.addItem(tekst + k, new Command() {

 @Override
 public void execute() {
 ClassMetodInterface metoda = (ClassMetodInterface) GWT.create(Method2.class);
 vPanel.clear(); //clearing before I open a new widget.

/*I sent int (easier to tests), but I can sent string[i] too*/
/* logging - instance of main class to communicate with 'subclasses', in my project necessery*/

 vPanel.add(metoda.defaultMethod(ii, logging)); 
 }

 });
 }
(...)
/*-------------------------------------------*/
ClassMetodInterface, only for implementation class Method2 :
/*-------------------------------------------*/
 public interface ClassMetodInterface {
 Widget defaultMethod(int g, Logging logging);
}

/*-------------------------------------------*/
class Method2 with swich:
/*-------------------------------------------*/


public class Method2 implements ClassMetodInterface {

 public Widget zapisUsera(int g, Logging logging) {

 Logging logging;
 HorizontalPanel lPanel = new HorizontalPanel();

 switch(g) {
 case 1: {
 Window.alert("switch for test no:"+g);
 MenuWindow1(logging);

 break;

 }
 case 2:{
 Window.alert("switch for test no:"+g);
 break;
 }
 default:
 Window.alert("switch default - loop &gt;2 &amp;&amp; &lt;1");
 break;
 }
 return lPanel; //all methods will be void - they will be add widgets and Panels to lPanel

 }

 public Widget MenuWindow1(Logging logging) {
 this.logging = logging;

 lPanel.setBorderWidth(2);
 this.lPanel.setPixelSize(100, 50); 
 Button b1 = new Button("test button, not used"); 
 lPanel.add(b1);

 Label lbl = new Label("label no "+logging.i); 

 lPanel.add(lbl);
 Button addGlobal = new Button("+");
 Button removeGlobal = new Button("-");
 lPanel.add(addGlobal);
 addGlobal.addClickHandler(new addGlobal());
 removeGlobal.addClickHandler(new removeGlobal());
 lPanel.add(removeGlobal);


 return lPanel;

 }

//for tests communication with class, where I have menu and global variable
 public class addGlobal implements ClickHandler {

 @Override
 public void onClick(ClickEvent event) {
 logging.i++;
 }

 }

 public class removeGlobal implements ClickHandler {

 @Override
 public void onClick(ClickEvent event) {
 logging.i--;
 }

 }
}
</code></pre>

It is not finished, but you can show main idea. If I need to add new options to menu, I will update db and replace one class for version with more methods.

My goal is to create a flexible application-> to extend the functionality of my web-application I only to add a position to the database and upload the missing class to the server.

I created dynamic menu in Java-GWT. I use MenuBar() and loops, all positions, wchich were taken from db (array, string).
Of course, 'end-option' in menu must do something, generally after clicking application will open i.e. FlowPanel with buttons, labels, textareas.

My idea was: using java reflection to add Command for all positions in menu.
Every Command take name of option (string), name is the same, like name of class -> next, after clicking I will automatically create object. Unfortunatelly Java Reflection don't work with GWT, so this way is not possible.

My question is:

How to create object, when I have class name in string? Or if my idea is wrong, maybye is other way to create flexible menu/program?

How to create new object in GWT by string class-name?

数据库

服务器

Java

我的目标是创建一个灵活的应用程序->为了扩展我的web应用程序的功能，我只需要在数据库中添加一个位置，并将缺少的类上传到服务器。我用Java-GWT创建了动态菜单。我使用MenuBar()和循环，所有位置都取自db (数组，字符串)。当然，菜单中的'end-option‘必须做一些事情，通常在点击后应用程序会打开，即带...

问如何通过字符串class-name在GWT中创建新对象？
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