代码中如何获得 Java 方法的形式参数名

 1package cc.unmi;
 2
 3import java.lang.reflect.Method;
 4import java.lang.reflect.Parameter;
 5
 6public class MethodParameterNames {
 7
 8  public static void main(String[] args) throws Exception{
 9    Method method = MethodParameterNames.class.getDeclaredMethod("foo", Integer.TYPE, String.class);
10    Parameter[] parameters = method.getParameters();
11    for(Parameter parameter: parameters) {
12      System.out.println(parameter.isNamePresent());
13      System.out.println(parameter.getType().getSimpleName() +": " + parameter.getName());
14    }
15  }
16
17  public void foo(int id, String name) {
18
19  }
20}

 1 /**
 2  * Retrieve parameter names of a method
 3  */
 4public static String[] parameterNames(Method method) throws Exception {
 5    try {
 6        /*System.out.println("searching for " + "$" + method.getName() + LVEnhancer.computeMethodHash(method.getParameterTypes()));
 7        for(Field f : method.getDeclaringClass().getDeclaredFields()) {
 8            System.out.println(f.getName() + " : " + Modifier.toString(f.getModifiers()));
 9        }
10        for(Field f : method.getDeclaringClass().getFields()) {
11            System.out.println(f.getName() + " : " + Modifier.toString(f.getModifiers()));
12        }*/
13        return (String[]) method.getDeclaringClass().getDeclaredField("$" + method.getName() + LVEnhancer.computeMethodHash(method.getParameterTypes())).get(null);
14    } catch (Exception e) {
15        throw new UnexpectedException("Cannot read parameter names for " + method, e);
16    }
17}

 1public static Integer computeMethodHash(Class<?>[] parameters) {
 2    String[] names = new String[parameters.length];
 3    for (int i = 0; i < parameters.length; i++) {
 4        Class<?> param = parameters[i];
 5        names[i] = "";
 6        if (param.isArray()) {
 7            int level = 1;
 8            param = param.getComponentType();
 9            // Array of array
10            while (param.isArray()) {
11                level++;
12                param = param.getComponentType();
13            }
14            names[i] = param.getName();
15            for (int j = 0; j < level; j++) {
16                names[i] += "[]";
17            }
18        } else {
19            names[i] = param.getName();
20        }
21    }
22    return computeMethodHash(names);
23}
24
25public static Integer computeMethodHash(String[] parameters) {
26    StringBuffer buffer = new StringBuffer();
27    for (String param : parameters) {
28        buffer.append(param);
29    }
30    Integer hash = buffer.toString().hashCode();
31    if (hash < 0) {
32        return -hash;
33    }
34    return hash;
35}