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If you aren't certain that a particular object is an array, you can check it with theClass.isArray
method. Let's take a look at an example.The sample program that follows prints the names of the arrays that are encapsulated in an object. The program performs these steps:
- It retrieves the
Class
object that represents the target object.- It gets the
Field
objects for theClass
object retrieved in step 1.- For each
Field
object, the program gets a correspondingClass
object by invoking thegetType
method.- To verify that the
Class
object retrieved in the preceding step represents an array, the program invokes theisArray
method.Here's the source code for the sample program:
The output of the sample program follows. Note that the left bracket indicates that the object is an array. For a detailed description of the type descriptors thatimport java.lang.reflect.*; import java.awt.*; class SampleArray { public static void main(String[] args) { KeyPad target = new KeyPad(); printArrayNames(target); } static void printArrayNames(Object target) { Class targetClass = target.getClass(); Field[] publicFields = targetClass.getFields(); for (int i = 0; i < publicFields.length; i++) { String fieldName = publicFields[i].getName(); Class typeClass = publicFields[i].getType(); String fieldType = typeClass.getName(); if (typeClass.isArray()) { System.out.println("Name: " + fieldName + ", Type: " + fieldType); } } } } class KeyPad { public boolean alive; public Button power; public Button[] letters; public int[] codes; public TextField[] rows; public boolean[] states; }getName
returns, see section 4.3.1 of The Java Virtual Machine Specification.Name: letters, Type: [Ljava.awt.Button; Name: codes, Type: [I Name: rows, Type: [Ljava.awt.TextField; Name: states, Type: [Z
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