how to get all variable and type data in class and method using java

Question

I have a class and i want to find all variable and type data.

for e.g

class ex
{
    String A,B;
    public void method()
    {
        int a;
        double C;
        String D;
    }
}

so i want output like this

A : String
B : String
a : int
C : double
D : String

Anderson Vieira · Accepted Answer · 2015-03-24T11:10:54.170

You can use the methods Class.getDeclaredMethods() and Class.getDeclaredFields() from the Reflection API to list a class methods and attributes.

for (Method m : ExampleClass.class.getDeclaredMethods()) {
    System.out.println(m.getName() + ": " + m.getGenericReturnType());
}

for (Field f : ExampleClass.class.getDeclaredFields()) {
    System.out.println(f.getName() + ": " + f.getType());
}

But you can not normally access the local variables information. In Java 8, you have access to the methods parameters using the method Method.getParameters(). So you could do:

for (Method m : ExampleClass.class.getDeclaredMethods()) {
    for (Parameter p : m.getParameters()) {
        System.out.println(p.getName() + ": " + p.getType());
    }
}

The parameter names are not stored by default in the .class files though, so the parameters will be listed as arg0, arg1, etc. To get the real parameter names you need to compile the source file with the -parameters option to the javac compiler.

sir i still can't get the local variable with your solution,have any idea for get the local variables sir?thanks — hendrianto, Apr 06 '15 at 06:39
@hendrianto The only local variables that you can normally access are the parameters. You could get some information about the others if you compile your program in debug mode and use a bytecode library. Check [this other answer](http://stackoverflow.com/questions/6816951/can-i-get-information-about-the-local-variables-using-java-reflection). — Anderson Vieira, Apr 06 '15 at 11:40

score 0 · Answer 2 · answered Mar 24 '15 at 10:44

0

check reflection, you can get all the info of a class on runtime

answered Mar 24 '15 at 10:44

Dani

161
4

you can't use reflection to get local variables here. – Ruchira Gayan Ranaweera Mar 24 '15 at 10:58

score 0 · Answer 3 · answered Mar 24 '15 at 10:58

0

You can use reflection to get A and B for sure. But you can't get same info for other local variables.

answered Mar 24 '15 at 10:58

Ruchira Gayan Ranaweera

34,993
17
75
115

so how can i get the local variables sir? – hendrianto Apr 06 '15 at 06:38

how to get all variable and type data in class and method using java

3 Answers3