Java Field getFloat()方法及示例

来源:这里教程网 时间:2026-02-17 20:50:41 作者:

Java Field getFloat()方法及示例

java.lang.reflect .FieldgetFloat() 方法用于获取必须是静态或实例字段类型的float的值。这个方法也用来获取另一个原始类型的值,该类型可以通过拓扑转换为float类型。当一个类包含一个静态或实例浮点字段,并且我们想获得该字段的值时,我们可以使用这个方法来返回Field的值。

语法

public float getFloat(Object obj)             throws IllegalArgumentException,                    IllegalAccessException

参数: 该方法接受一个单参数 obj ,它是要提取浮动值的对象。

返回值: 该方法返回转换为float类型的字段的值。

异常: 该方法会抛出以下异常。

    IllegalAccessException: 如果Field对象正在执行Java语言的访问控制,而底层字段是不可访问的,就会抛出这个异常。IllegalArgumentException: 如果指定的对象不是声明底层字段的类或接口的实例,或者如果字段值不能通过拓扑转换为float类型,则抛出该异常。NullPointerException: 如果指定的对象是空的,并且该字段是一个实例字段,就会抛出这个异常。ExceptionInitializerError: 如果该方法引发的初始化失败,则抛出该异常。

以下程序说明了getFloat()方法:

程序1 :

// Java program to demonstrate the getFloat() method  import java.lang.reflect.Field;  public class GFG {      public static void main(String[] args)        throws NoSuchFieldException,               SecurityException,               IllegalArgumentException,               IllegalAccessException    {          // Create the User class object        User user = new User();          // Get the marks field object        Field field = User.class.getField("Marks");          // Apply getFloat Method on User Object        // to get the value of Marks field        float value = field.getFloat(user);          // print result        System.out.println("Value of float Field"                           + " Marks is " + value);          // Now Get the Fees field object        field = User.class.getField("Fees");          // Apply getFloat Method on User Object        // to get the value of Fees field        value = field.getFloat(user);          // print result        System.out.println("Value of float Field"                           + " Fees is " + value);    }}  // sample User classclass User {      // static float values    public static float Marks = 94.13f;    public static float Fees = 1343413.99f;    public static String name = "Aman";      public static float getMarks()    {        return Marks;    }      public static void setMarks(float marks)    {        Marks = marks;    }      public static float getFees()    {        return Fees;    }      public static void setFees(float fees)    {        Fees = fees;    }      public static String getName()    {        return name;    }      public static void setName(String name)    {        User.name = name;    }}

输出:

Value of float Field Marks is 94.13Value of float Field Fees is 1343414.0

程序2

// Java program to demonstrate the getFloat() method  import java.lang.reflect.Field;  public class GFG {      public static void main(String[] args)        throws NoSuchFieldException,               SecurityException,               IllegalArgumentException,               IllegalAccessException    {          // Create the RealNumbers class object        RealNumbers real = new RealNumbers();          // Get the value field object        Field field            = RealNumbers.class                  .getField("value");          // Apply getFloat Method on field Object        // to get the value of value field        float value = field.getFloat(real);          // print result        System.out.println("Value: " + value);    }      // RealNumbers class    static class RealNumbers {          // float field        public static float value            = 123432123.1234f;          // getter and setter methods        public static float getValue()        {            return value;        }          public static void setValue(float value)        {            RealNumbers.value = value;        }    }}

输出:

Value: 1.2343212E8

参考文献 : https://docs.oracle.com/javase/8/docs/api/java/lang/reflect/Field.html#getFloat-java.lang.Object-

相关推荐