java.lang.reflect.Field的setBoolean()方法用于將字段的值設(shè)置為指定對(duì)象上的布爾值。當(dāng)需要將對(duì)象的字段的值設(shè)置為布爾值時(shí)，可以使用此方法在對(duì)象上設(shè)置值。

用法:

public void setBoolean(Object obj, boolean z)

throws IllegalArgumentException,

IllegalAccessException

參數(shù)：此方法接受兩個(gè)參數(shù)：

obj：是應(yīng)該修改其字段的對(duì)象，并且

z：這是要修改的obj字段的新值。

返回值：此方法不返回任何內(nèi)容。

異常：此方法引發(fā)以下異常：

IllegalAccessException：如果此Field對(duì)象正在實(shí)施Java語(yǔ)言訪問控制，并且基礎(chǔ)字段是不可訪問的或最終的。

IllegalArgumentException：如果指定的對(duì)象不是聲明基礎(chǔ)字段(或其子類或?qū)崿F(xiàn)者)的類或接口的實(shí)例，或者展開的轉(zhuǎn)換失敗。

NullPointerException：如果指定的對(duì)象為null并且該字段是實(shí)例字段。

ExceptionInInitializerError：如果此方法引發(fā)的初始化失敗。

以下示例程序旨在說明setBoolean()方法：

示例1:

// Java program to illustrate setBoolean() method

import java.lang.reflect.Field;

public class GFG {

public static void main(String[] args)

throws Exception

{

// create user object

User user = new User();

// print value of isActive

System.out.println("Value before "

+ "applying setBoolean is "

+ user.isActive);

// Get the marks field object

Field field

= User.class

.getField("isActive");

// Apply setBoolean Method

field.setBoolean(field, false);

// print result

System.out.println("Value after "

+ "applying setBoolean is "

+ user.isActive);

}

}

// sample User class

class User {

// static boolean values

public static boolean isActive = true;

}

輸出：

Value before applying setBoolean is true

Value after applying setBoolean is false

示例2:

// Java program to illustrate setBoolean() method

import java.lang.reflect.Field;

public class GFG {

public static void main(String[] args)

throws Exception

{

// create user object

Employee emp = new Employee();

// print value of isManager

System.out.println("Value of isManager before "

+ "applying setBoolean is "

+ emp.isManager);

// Get the marks field object

Field field

= Employee.class

.getField("isManager");

// Apply setBoolean Method

field.setBoolean(emp, false);

// print value of isActive

System.out.println("Value of isPresent before "

+ "applying setBoolean is "

+ emp.isManager);

// print value of isManager

System.out.println("Value of isManager before "

+ "applying setBoolean is "

+ emp.isPresent);

// Get the marks field object

field = Employee.class

.getField("isPresent");

// Apply setBoolean Method

field.setBoolean(emp, true);

// print value of isActive

System.out.println("Value of isPresent before "

+ "applying setBoolean is "

+ emp.isPresent);

}

}

// sample User class

class Employee {

// static boolean values

public static boolean isPresent = false;

public static boolean isManager = true;

}

輸出：

Value of isManager before applying setBoolean is true

Value of isPresent before applying setBoolean is false

Value of isManager before applying setBoolean is false

Value of isPresent before applying setBoolean is true

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