The example below using reflection to obtain the fields of a class object. We’ll get the field names and their corresponding type. There are three ways shown below which can be use to get an object fields:
Class.getDeclaredFields()Class.getFields()Class.getField(String)
package org.kodejava.example.lang;
import java.util.Date;
import java.lang.reflect.Field;
public class GetFields {
public Long id;
protected String name;
private Date birthDate;
Double weight;
public static void main(String[] args) {
GetFields object = new GetFields();
Class clazz = object.getClass();
//
// Get all object fields including public, protected, package and private
// access fields.
//
Field[] fields = clazz.getDeclaredFields();
System.out.println("Number of fields = " + fields.length);
for (Field field : fields) {
System.out.println("Field name = " + field.getName());
System.out.println("Field type = " + field.getType().getName());
}
System.out.println("n----------------------------------------n");
//
// Get all object accessible public fields.
//
fields = clazz.getFields();
System.out.println("Number of fields = " + fields.length);
for (Field field : fields) {
System.out.println("Field name = " + field.getName());
System.out.println("Field type = " + field.getType().getName());
}
System.out.println("n----------------------------------------n");
try {
//
// Get field name id with public access modifier
//
Field field = clazz.getField("id");
System.out.println("Field name = " + field.getName());
System.out.println("Field type = " + field.getType().getName());
} catch (NoSuchFieldException e) {
e.printStackTrace();
}
}
}
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