![]() ![]() But I'm not sure whether it will work for all cases.Īnd after that you will get decompiled bytecode. In my case I have to look at symbols like that: Êþº¾Īnd to delete all data before them. So you should open it in notepad and try to delete symbols at the beginning until java.exe will be able to decompile it. Unfortunately you can't just decompile it right after this, cause code in this table helds some extra data at the beginning, and javap.exe will give an error. You open the code in text editor and save it. So you get the code like that: select a.obj#,a.code,b.name ![]() All javaclass codes are stored in the table sys.idl_ub1$ in long raw format. Secondly, if you don't have grant to read it and by some reasons you don't want to get it, you can extract javaclass code another way. It's readable, although you need to know JVM instructions. Something like that: C:\Programm Files\Java\JDK\bin\javap.exe -c -s -verbose C:\Exports\file.class You need to open cmd.exe (if you work on Windows), print there path to javap.exe on your computer, than after space "-c -s -verbose" and than after another space path to the *class file you've created. The static nested class StaticNestedClass can't directly access outerField because it's an instance variable of the enclosing class, OuterClass.Sorry, if it's a lil bit too late, but I've recently struggled with the same problem and maybe it can help someone.įirst of all, if you have grant to load javaclass code via export_class, than all you need after you've exported it is to decompile it with javap.exe. Note that a static nested class interacts with the instance members of its outer class just like any other top-level class. This example prints the following output: Inner class: TopLevelObject.accessMembers(outerObject) TopLevelClass topLevelObject = new TopLevelClass() StaticNestedObject.accessMembers(outerObject) OuterClass.InnerClass innerObject = outerObject.new InnerClass() ![]() OuterClass outerObject = new OuterClass() Compiler error: Cannot make a static reference to the non-static View java class source in oracle database java class code that is compiled in database java class is compiled successfully and is valid query java object in. ![]() Static String staticOuterField = "Static outer field" TopLevelClass, demonstrates which class members of OuterClass an inner class ( InnerClass), a nested static class ( StaticNestedClass), and a top-level class ( TopLevelClass) can access: OuterClass.java Inner Class and Nested Static Class Example StaticNestedClass staticNestedObject = new StaticNestedClass() Objects that are instances of an inner class exist within an instance of the outer class. Also, because an inner class is associated with an instance, it cannot define any static members itself. It can lead to more readable and maintainable code: Nesting small classes within top-level classes places the code closer to where it is used.Īs with instance methods and variables, an inner class is associated with an instance of its enclosing class and has direct access to that object's methods and fields. In addition, B itself can be hidden from the outside world. By hiding class B within class A, A's members can be declared private and B can access them. It increases encapsulation: Consider two top-level classes, A and B, where B needs access to members of A that would otherwise be declared private. Nesting such "helper classes" makes their package more streamlined. It is a way of logically grouping classes that are only used in one place: If a class is useful to only one other class, then it is logical to embed it in that class and keep the two together. (Recall that outer classes can only be declared public or package private.) Why Use Nested Classes?Ĭompelling reasons for using nested classes include the following: Download a PDF of this article More quiz questions available here Which of the following statements are correct about a Java class Choose two. As a member of the OuterClass, a nested class can be declared private, public, protected, or package private. J 4 minute read Mikalai Zaikin Simon Roberts Test your knowledge of Java classes, such as their valid names, the use of variables inside a method, and the number of allowable import statements. Static nested classes do not have access to other members of the enclosing class. Non-static nested classes (inner classes) have access to other members of the enclosing class, even if they are declared private. A nested class is a member of its enclosing class. ![]()
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