如何测试方法返回类型是否与List <String>匹配

我尝试了这个代码,它返回实际的泛型类,所以似乎可以检索类型信息.但是这只适用于方法1和2.方法3似乎没有返回列表类型的字符串,因为海报假定因此失败.

public class Main {
/**
 * @param args the command line arguments
 */
public static void main(String[] args) {
    try{
        Method m = Main.class.getDeclaredMethod("method1", new Class[]{});
        instanceOf(m, List.class, String.class);
        m = Main.class.getDeclaredMethod("method2", new Class[]{});
        instanceOf(m, List.class, String.class);
        m = Main.class.getDeclaredMethod("method3", new Class[]{});
        instanceOf(m, List.class, String.class);
        m = Main.class.getDeclaredMethod("method4", new Class[]{});
        instanceOf(m, StringList.class);
    }catch(Exception e){
        System.err.println(e.toString());
    }
}

public static boolean instanceOf (
        Method m, 
        Class returnedBaseClass, 
        Class ... genericParameters) {
    System.out.println("Testing method: " + m.getDeclaringClass().getName()+"."+ m.getName());
    boolean instanceOf = false;
    instanceOf = returnedBaseClass.isAssignableFrom(m.getReturnType());
    System.out.println("\tReturn type test succesfull: " + instanceOf + " (expected '"+returnedBaseClass.getName()+"' found '"+m.getReturnType().getName()+"')");
    System.out.print("\tNumber of generic parameters matches: ");
    Type t = m.getGenericReturnType();
    if(t instanceof ParameterizedType){
        ParameterizedType pt = (ParameterizedType)t;
        Type[] actualGenericParameters = pt.getActualTypeArguments();
        instanceOf = instanceOf
            && actualGenericParameters.length == genericParameters.length;
        System.out.println("" + instanceOf + " (expected "+ genericParameters.length +", found " + actualGenericParameters.length+")");
        for (int i = 0; instanceOf && i < genericParameters.length; i++) {
            if (actualGenericParameters[i] instanceof Class) {
                instanceOf = instanceOf
                        && genericParameters[i].isAssignableFrom(
                            (Class) actualGenericParameters[i]);
                System.out.println("\tGeneric parameter no. " + (i+1) + " matches: " + instanceOf + " (expected '"+genericParameters[i].getName()+"' found '"+((Class) actualGenericParameters[i]).getName()+"')");
            } else {
                instanceOf = false;
                System.out.println("\tFailure generic parameter is not a class");
            }
        }
    } else {
        System.out.println("" + true + " 0 parameters");
    }
    return instanceOf;
}
public List method1() {
    return null;
}
public ArrayList method2() {
    return new ArrayList();
}
public StringList method3() {
    return null;
}
public  T method4() {
    return null;
}

这输出:

Testing method: javaapplication2.Main.method1
        Return type test succesfull: true (expected 'java.util.List' found 'java.util.List')
        Number of generic parameters matches: true (expected 1, found 1)
        Generic parameter no. 1 matches: true (expected 'java.lang.String' found 'java.lang.String')
Testing method: javaapplication2.Main.method2
        Return type test succesfull: true (expected 'java.util.List' found 'java.util.ArrayList')
        Number of generic parameters matches: true (expected 1, found 1)
        Generic parameter no. 1 matches: true (expected 'java.lang.String' found 'java.lang.String')
Testing method: javaapplication2.Main.method3
        Return type test succesfull: false (expected 'java.util.List' found 'com.sun.org.apache.xerces.internal.xs.StringList')
        Number of generic parameters matches: true 0 parameters
Testing method: javaapplication2.Main.method4
        Return type test succesfull: true (expected 'com.sun.org.apache.xerces.internal.xs.StringList' found 'com.sun.org.apache.xerces.internal.xs.StringList')
        Number of generic parameters matches: true 0 parameters