在试图写测试用例出现这个问题。 foo是框架库，我没有到源代码访问中的一类。
public class Foo{
public final Object getX(){
...
}
}
我的应用程序会
public class Bar extends Foo{
public int process(){
Object value = getX();
...
}
}
单元测试情况下是无法初始化为我不能由于其他依赖创建Foo对象。所述BarTest抛出一个空指针作为值为空。
public class BarTest extends TestCase{
public testProcess(){
Bar bar = new Bar();
int result = bar.process();
...
}
}
有没有一种方法，我可以使用反射API到的getX（）设置为非决赛？或者我应该如何去测试？
你可以创建你可以在您的测试覆盖另一种方法：
public class Bar extends Foo {
protected Object doGetX() {
return getX();
}
public int process(){
Object value = doGetX();
...
}
}
然后，你可以在BarTest覆盖doGetX。
由于这是在谷歌“重写最后方法的java”顶部结果中的一个。我以为我会离开我的解决方案。这个类展示了使用如“贝果”类和免费使用了Javassist库的简单解决方案：
/**
* This class shows how you can override a final method of a super class using the Javassist's bytecode toolkit
* The library can be found here: http://jboss-javassist.github.io/javassist/
*
* The basic idea is that you get the super class and reset the modifiers so the modifiers of the method don't include final.
* Then you add in a new method to the sub class which overrides the now non final method of the super class.
*
* The only "catch" is you have to do the class manipulation before any calls to the class happen in your code. So put the
* manipulation as early in your code as you can otherwise you will get exceptions.
*/
package packagename;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.CtMethod;
import javassist.CtNewMethod;
import javassist.Modifier;
/**
* A simple class to show how to use the library
*/
public class TestCt {
/**
* The starting point for the application
*/
public static void main(String[] args) {
// in order for us to override the final method we must manipulate the class using the Javassist library.
// we need to do this FIRST because once we initialize the class it will no longer be editable.
try
{
// get the super class
CtClass bagel = ClassPool.getDefault().get("packagename.TestCt$Bagel");
// get the method you want to override
CtMethod originalMethod = bagel.getDeclaredMethod("getDescription");
// set the modifier. This will remove the 'final' modifier from the method.
// If for whatever reason you needed more than one modifier just add them together
originalMethod.setModifiers(Modifier.PUBLIC);
// save the changes to the super class
bagel.toClass();
// get the subclass
CtClass bagelsolver = ClassPool.getDefault().get("packagename.TestCt$BagelWithOptions");
// create the method that will override the super class's method and include the options in the output
CtMethod overrideMethod = CtNewMethod.make("public String getDescription() { return super.getDescription() + \" with \" + getOptions(); }", bagelsolver);
// add the new method to the sub class
bagelsolver.addMethod(overrideMethod);
// save the changes to the sub class
bagelsolver.toClass();
}
catch (Exception e)
{
e.printStackTrace();
}
// now that we have edited the classes with the new methods, we can create an instance and see if it worked
// create a new instance of BagelWithOptions
BagelWithOptions myBagel = new BagelWithOptions();
// give it some options
myBagel.setOptions("cheese, bacon and eggs");
// print the description of the bagel to the console.
// This should now use our new code when calling getDescription() which will include the options in the output.
System.out.println("My bagel is: " + myBagel.getDescription());
// The output should be:
// **My bagel is: a plain bagel with cheese, bacon and eggs**
}
/**
* A plain bagel class which has a final method which we want to override
*/
public static class Bagel {
/**
* return a description for this bagel
*/
public final String getDescription() {
return "a plain bagel";
}
}
/**
* A sub class of bagel which adds some extra options for the bagel.
*/
public static class BagelWithOptions extends Bagel {
/**
* A string that will contain any extra options for the bagel
*/
String options;
/**
* Initiate the bagel with no extra options
*/
public BagelWithOptions() {
options = "nothing else";
}
/**
* Set the options for the bagel
* @param options - a string with the new options for this bagel
*/
public void setOptions(String options) {
this.options = options;
}
/**
* return the current options for this bagel
*/
public String getOptions() {
return options;
}
}
}
勒布是正确的，只是确保你得到一个回答你的问题，在原生代码做一些事情的（我敢肯定那就没办法了），或者修改类的字节码在运行时，并创建类覆盖方法在运行时，我看不到的方式来改变的方法“finalness”。反射不会帮助你在这里。
如果你的单元测试的情况下不能创建美孚由于其他的依赖关系，这可能是你没有将你的单元测试的权利摆在首位的标志。
单元测试是指在相同条件下生产的代码将运行测试，所以我建议你重新创建测试内部相同的生产环境。否则，你的测试将是不完整的。
如果getX()返回的变量不final您可以使用该技术在What’s the best way of unit testing private methods?解释了通过private改变Reflection变量的值。
public class Bar extends Foo{
public int process(){
Object value = getX();
return process2(value);
}
public int process2(Object value){
...
}
}
public class BarTest extends TestCase{
public testProcess(){
Bar bar = new Bar();
Mockobj mo = new Mockobj();
int result = bar.process2(mo);
...
}
}
我做了什么，而最终在上面。这是一个有点难看......詹姆斯的解决方案肯定比这更好？