如何通过反射访问私有变量和私有方法

系统管理员 2022-06-13 09:24 224阅读 0赞

package tiaoshi;  
  
  
public class PrivateObject \{  
private String privateString = null;  
public PrivateObject(String privateString) \{  
// TODO Auto-generated constructor stub  
this.privateString = privateString;  
\}  
  
private String getPrivateString()\{  
return this.privateString;

private void setPricateString(String privateString)\{  
this.privateString = privateString;  
\}

测试类：

package tiaoshi;  
  
  
import java.lang.reflect.Field;  
import java.lang.reflect.Method;  
  
  
public class ceshi \{  
public static void main (String \[\]args)\{  
//访问私有变量  
PrivateObject kObject= new PrivateObject("the test");  
try \{  
Field kField = PrivateObject.class.getDeclaredField("privateString");  
kField.setAccessible(true);  
String kString = (String)kField.get(kObject);  
System.out.println(kString);  
  
  
\} catch (Exception e) \{  
// TODO: handle exception  
\}  
  
//访问私有方法  
PrivateObject kObject1= new PrivateObject("the test");  
try \{  
Method kField1 = PrivateObject.class.getDeclaredMethod("getPrivateString", null);  
kField1.setAccessible(true);  
String kk = (String)kField1.invoke(kObject1, null);  
System.out.println(kk);  
\} catch (Exception e) \{  
// TODO: handle exception  
\}

PrivateObject kObject2 = new PrivateObject();

try \{

Method gg = PrivateObject.class.getDeclaredMethod("setPricateString",  String.class);

gg.setAccessible(true);

gg.invoke(kObject2, "5555");

Method tt = PrivateObject.class.getDeclaredMethod("getPrivateString", null);

tt.setAccessible(true);

String dd = (String) tt.invoke(kObject2, null);

System.out.println(dd);

\} catch (Exception e) \{

// TODO: handle exception

\}  
\}