package myPackage;
import java.awt.*;
public class Calculation {
int z;
public void addition(int x, int y) {
z=x+y;
System.out.println("sum of given input: "+z);
}
public void subtraction(int x, int y) {
z=x+y;
System.out.println("diff btwn given input: " +z);
}
}
...............
package myPackage;
public class MyCalculation extends Calc {
public void multiplication(int x, int y) {
//z=x*y;
System.out.println("product of given input: "+ x*y);
}
}
..............
package myPackage;
public class Main {
public static void main(String[] args) {
int a=20; int b=10;
MyCalculation demo = new MyCalculation();
demo.addition(a, b);
demo.subtraction(a, b);
demo.multiplication(a, b);
}
}
This was my code, it's showing an error saying :
Description Resource Path Location Type No enclosing instance of type
Calculation is accessible. Must qualify the allocation with an
enclosing instance of type Calculation (e.g. x.new A() where x is an
instance of Calculation).
Any solution ?
Related
Trying to apply a MockUp on a Java 8 default interface method, and JMockit tells me that method cannot be found. This has been tried with JMockit 1.15, 1.19, and 1.25. Here's a very simple use case:
#RunWith(JMockit.class)
public class TestTest {
public interface MyInterface {
default void foo(int f) {
bar(String.valueOf(f));
}
void bar(String s);
}
public class MyClass implements MyInterface {
public void bar(String s) {
System.out.println(s);
}
}
#Test
public void testtest() throws Exception {
new MockUp<MyClass>() {
#Mock
void foo(int i) {
System.out.println("MOCKMOCK " + (i*2));
}
#Mock
void bar(String s) {
System.out.println("MOCK " + s);
}
};
MyClass baz = new MyClass();
baz.foo(5);
baz.bar("Hello world");
}
}
This gets me the error
java.lang.IllegalArgumentException: Matching real methods not found for the following mocks:
com.example.dcsohl.TestTest$1#foo(int)
at com.example.dcsohl.TestTest$1.<init>(TestTest.java:29)
at com.example.dcsohl.TestTest.testtest(TestTest.java:29)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
...
How can we #Mock this method?
Slightly modifying your use case to return strings instead of printing to standard out the following solution will work.
import static org.junit.Assert.assertEquals;
import org.junit.Test;
import mockit.Expectations;
public class TestTest {
public interface MyInterface {
default String foo(int f) {
return bar(String.valueOf(f));
}
String bar(String s);
}
public class MyClass implements MyInterface {
public String bar(String s) {
return s;
}
}
#Test
public void testtest() throws Exception {
MyClass baz = new MyClass();
new Expectations(MyClass.class) {{
baz.foo(anyInt); result = "FOOMOCK";
baz.bar(anyString); result = "BARMOCK";
}};
assertEquals(baz.foo(5), "FOOMOCK");
assertEquals(baz.bar("Hello world"), "BARMOCK");
}
}
There are many useful examples of how to mock out interfaces with method bodies (ie default or static methods) outlined in the examples section on the jmockit github repository.
Use #Mocked instead of a MockUp, it supports default methods.
I'm using JNA to run a dll function:
Here is all the code corresponding to that manner:
The Native Declarations:
//how the method declared
H264_Login (char *sIP, unsigned short wPort, char *sUserName, char *sPassword, LP_DEVICEINFO lpDeviceInfo, int *error, ，SocketStyle socketTyle=TCPSOCKET); // where LP_DEVICEINFO is a struct
//how the struct declared
typedef struct _H264_DVR_DEVICEINFO
{
SDK_SYSTEM_TIME tmBuildTime; // the "SDK_SYSTEM_TIME" is another struct
char sSerialNumber[64];
int byChanNum;
unsigned int uiDeviceRunTime;
SDK_DeviceType deviceTye; // the "SDK_DeviceType" is a enum
}H264_DVR_DEVICEINFO,*LP_DEVICEINFO;
// this is how "SDK_SYSTEM_TIME" is defined
typedef struct SDK_SYSTEM_TIME{
int year;
int month;
int day;
}SDK_SYSTEM_TIME;
// this is how "SDK_DeviceType" is defined
enum SDK_DeviceType
{
SDK_DEVICE_TYPE_DVR,
SDK_DEVICE_TYPE_MVR,
SDK_DEVICE_TYPE_NR
};
// this is how "SocketStyle" is defined
enum SocketStyle
{
TCPSOCKET=0,
UDPSOCKET,
SOCKETNR
};
The following is their corresponding Java mappings:
public class Test implements StdCallLibrary {
public interface simpleDLL extends StdCallLibrary {
long H264_Login(String sIP, short wPort, String sUserName, String sPassword,
Structure DeviceDate, int error, int TCPSOCKET);
}
static
{
System.loadLibrary("NetSdk");
}
// the struct implementation
public static class DeviceDate extends Structure{
public SDK_SYSTEM_TIME tmBuildTime;
public String sSerialNumber;
public IntByReference byChanNum;
public IntByReference uiDeviceRunTime;
public IntByReference deviceTpye;
#Override
protected List<Object> getFieldOrder() {
List<Object> list = new ArrayList<>();
list.add("tmBuildTime");
list.add("sSerialNumber");
list.add("byChanNum");
list.add("uiDeviceRunTime");
list.add("deviceTpye");
return list;
}
}
public static class SDK_SYSTEM_TIME extends Structure{
public IntByReference year;
public IntByReference month;
public IntByReference day;
#Override
protected List<Object> getFieldOrder() {
List<Object> list = new ArrayList<>();
list.add("year");
list.add("month");
list.add("day");
return list;
}
}
// and then how I called it through the main function
public static void main(String args[]) throws FileNotFoundException{
simpleDLL INSTANCE = (simpleDLL) Native.loadLibrary( ("NetSdk"), simpleDLL.class);
DeviceDate dev = new DeviceDate() // where DeviceDate is a static class inherits com.sun.jna.Structure
int err = (int) INSTANCE.H264_GetLastError();
long result = INSTANCE.H264_Login("255.255.255.255", (short) 33333, "admin", "admin", dev, err, 0);
}
}
upon running the app, the Java crashes:
and this is the full problem signature:
Problem signature:
Problem Event Name: APPCRASH
Application Name: javaw.exe
Application Version: 7.0.600.19
Application Timestamp: 536a95c6
Fault Module Name: jna3976113557901128571.dll
Fault Module Version: 4.0.0.215
Fault Module Timestamp: 52d3949a
Exception Code: c0000005
Exception Offset: 0000e3a2 OS
Version: 6.1.7601.2.1.0.256.1
Locale ID: 1033
Additional Information 1: 7bc2
Additional Information 2: 7bc24d73a5063367529b81d28aecc01c
Additional Information 3: 5bea
Additional Information 4: 5beaa1c0441c3adb156a170a61c93d19
Read our privacy statement online:
http://go.microsoft.com/fwlink/?linkid=104288&clcid=0x0409
If the online privacy statement is not available, please read our
privacy statement offline: C:\Windows\system32\en-US\erofflps.txt
Your mappings have a number of errors. Your structures should look like the following (IntByReference represents places where you would pass the address of an int, and you can't substitute String for a primitive native char array). Please refer to the JNA mapping documentation to ensure you understand how native types map to Java types:
public static class LP_DEVICE_INFO extends Structure{
public SDK_SYSTEM_TIME tmBuildTime;
public byte[] sSerialNumber = new byte[64];
public int byChanNum;
public int uiDeviceRunTime;
public int deviceType; // Assuming the size of the enum is int
#Override
protected List<Object> getFieldOrder() {
List<Object> list = new ArrayList<>();
list.add("tmBuildTime");
list.add("sSerialNumber");
list.add("byChanNum");
list.add("uiDeviceRunTime");
list.add("deviceTpye");
return list;
}
}
public static class SDK_SYSTEM_TIME extends Structure{
public int year;
public int month;
public int day;
#Override
protected List<Object> getFieldOrder() {
List<Object> list = new ArrayList<>();
list.add("year");
list.add("month");
list.add("day");
return list;
}
}
i want to convert that line from c# to c++/cli
Idocobj is IPart
IPart is an interface and Idocobj is an object.Are there any way to do this conversion.
i used this code :
Idocobj->GetType() == IPart::typeid
but it dosen't work
You can use dynamic_cast to check for "is". Here is an example:
using namespace System;
namespace NS
{
public interface class IFoo
{
void Test();
};
public ref class Foo : public IFoo
{
public: virtual void Test() {}
};
public ref class Bar
{
public: virtual void Test() {}
};
}
template<class T, class U>
bool isinst(U u) {
return dynamic_cast< T >(u) != nullptr;
}
int main()
{
NS::Foo^ f = gcnew NS::Foo();
NS::Bar^ b = gcnew NS::Bar();
if (isinst<NS::IFoo^>(f))
Console::WriteLine("f is IFoo");
if (isinst<NS::IFoo^>(b) == false)
Console::WriteLine("f is not IFoo");
Console::ReadKey();
}
But normally, you never use "is".... you always want to do something with the check... so normally you should use "as" which directly mapps to dynamic_cast:
NS::IFoo^ ifoo = dynamic_cast<NS::IFoo^>(f);
if (ifoo != nullptr)
{
// Do something...
ifoo->Test();
}
after decompiling my interface i found out that proguard duplicated my implemented method in the upper level interface that is somehow a class on its own right.
here's how my interface looks like after obfuscation (note that proguard even added the annotation from the implementation)
package com.company.project.f.a.a;
import java.util.List;
import org.apache.log4j.Logger;
#Component(value="ServiceImpl")
public class a
{
public b a(int i)
{
if((i = b.a(i)) != null)
{
if(i.size() == 0)
{
a_.fatal("It is expected at least one record.");
return null;
} else
{
return (b)i.get(0);
}
} else
{
return null;
}
}
public a()
{
a_ = Logger.getLogger(getClass());
}
public com.company.project.b.a.a a()
{
return b;
}
public void a(com.company.project.b.a.a a1)
{
b = a1;
}
private com.company.project.b.a.a b;
Logger a_;
}
same issue happened with the class below (proguard transforming the interface into a class with the same component name)
#Component("testDao")
public class TestDaoImpl implements TestDao {
#Override
public void testing() {
// TODO Auto-generated method stub
}
solved it :
according to mr eric lafortune , the optimizer is merging interface and class .
so i used
-dontoptimize
I am trying to achieve something like the following:
class Foo
{
public virtual int Number { get; set; }
public Foo(int n)
{
Number = n; //Virtual member call in constructor
}
public void Do() {
Console.WriteLine(Number);
}
}
class Bar : Foo
{
public override int Number
{
get
{
return x.Val;
}
set
{
x.Val = value;
}
}
Bar(int n) : base(n)
{
X x = new X();
x.Val = n;
}
public void F() {
x.Something(); //changes x.Val
}
}
The reason I am doing this is because I need to propagate the call to Do when called from a variable of type Bar.
Now, I can have objects that either inherit from Foo or Bar, thus Number needs to be the way it is now, ie directly expose the Val property of x. This is because I need to allow for the following code:
Bar b = new Bar(5);
b.F(); //changes the value of Val in x
b.Do(); //Needs to print the correct, modified value
The problem here is obviously in Foo, when assigning n to Number (Virtual member call in constructor) since x from the subclass would not have been initialized yet.
What do you think is a better way to structure such a design?
I can't use this current code because I am calling a virtual member from the constructor, which causes the Object Reference not set to an Instance of an Object exception since x in Number from Bar would not have been yet initialized.
My favorite quote:
Favor composition over inheritance
I would separate underlying data from operations:
interface IMyNumber
{
int Number { get; set; }
void Something();
}
class MyNumber : IMyNumber
{
public int Number { get; set; }
public MyNumber(int n)
{
Number = n;
}
void Something() {... }
}
class MyBoxedNumber : IMyNumber
{
int Number { get { ... } set {... } }
void Something() {... }
}
class Bar
{
private IMyNumber_foo;
Bar(IMyNumber foo)
{
_foo = foo;
}
public void F() {
_foo.Something(); //changes x.Val
}
public void Do() {
Console.WriteLine(...)
}
}