1.1 getMethod

  1.  public Method getMethod(String name, Class<?>... parameterTypes)
  2.         throws NoSuchMethodException, SecurityException {
  3.         checkMemberAccess(Member.PUBLIC, Reflection.getCallerClass(), true);
  4.         Method method = getMethod0(name, parameterTypes, true);
  5.         if (method == null) {
  6.             throw new NoSuchMethodException(getName() + "." + name + argumentTypesToString(parameterTypes));
  7.         }
  8.         return method;
  9.     }

校验公共方法

1.1.1 getMethod0

  1. private Method getMethod0(String name, Class<?>[] parameterTypes, boolean includeStaticMethods) {
  2.         MethodArray interfaceCandidates = new MethodArray(2);
  3.         Method res =  privateGetMethodRecursive(name, parameterTypes, includeStaticMethods, interfaceCandidates);
  4.         if (res != null)
  5.             return res;
  7.         // Not found on class or superclass directly
  8.         interfaceCandidates.removeLessSpecifics();
  9.         return interfaceCandidates.getFirst(); // may be null
  10.     }

1.1.2 privateGetMethodRecursive

递归调用此类或者是超类或接口

  1.  private Method privateGetMethodRecursive(String name,
  2.             Class<?>[] parameterTypes,
  3.             boolean includeStaticMethods,
  4.             MethodArray allInterfaceCandidates) {
  5.         if ((res = searchMethods(privateGetDeclaredMethods(true),
  6.                                  name,
  7.                                  parameterTypes)) != null) {
  8.             if (includeStaticMethods || !Modifier.isStatic(res.getModifiers()))
  9.                 return res;
  10.         }
  11.         // Search superclass's methods
  12.         if (!isInterface()) {
  13.             Class<? super T> c = getSuperclass();
  14.             if (c != null) {
  15.                 if ((res = c.getMethod0(name, parameterTypes, true)) != null) {
  16.                     return res;
  17.                 }
  18.             }
  19.         }
  20.         // Search superinterfaces' methods
  21.         Class<?>[] interfaces = getInterfaces();
  22.         for (Class<?> c : interfaces)
  23.             if ((res = c.getMethod0(name, parameterTypes, false)) != null)
  24.                 allInterfaceCandidates.add(res);
  25.         // Not found
  26.         return null;
  27.     }

1.1.3 privateGetDeclaredMethods

从缓存或JVM中获取该Class中申明的方法列表

  1. private Method[] privateGetDeclaredMethods(boolean publicOnly) {
  2.         checkInitted();
  3.         Method[] res;
  4.         ReflectionData<T> rd = reflectionData();
  5.         if (rd != null) {
  6.             res = publicOnly ? rd.declaredPublicMethods : rd.declaredMethods;
  7.             if (res != null) return res;
  8.         }
  9.         // No cached value available; request value from VM
  10.         res = Reflection.filterMethods(this, getDeclaredMethods0(publicOnly));
  11.         if (rd != null) {
  12.             if (publicOnly) {
  13.                 rd.declaredPublicMethods = res;
  14.             } else {
  15.                 rd.declaredMethods = res;
  16.             }
  17.         }
  18.         return res;
  19.     }

1.1.4 reflectionData

  1. private ReflectionData<T> reflectionData() {
  2.         SoftReference<ReflectionData<T>> reflectionData = this.reflectionData;
  3.         int classRedefinedCount = this.classRedefinedCount;
  4.         ReflectionData<T> rd;
  5.         if (useCaches &&
  6.             reflectionData != null &&
  7.             (rd = reflectionData.get()) != null &&
  8.             rd.redefinedCount == classRedefinedCount) {
  9.             return rd;
  10.         }
  11.         // else no SoftReference or cleared SoftReference or stale ReflectionData
  12.         // -> create and replace new instance
  13.         return newReflectionData(reflectionData, classRedefinedCount);
  14.     }

reflectionData对象是SoftReference类型的，说明在内存紧张时可能会被回收，如果被回收了，再调用反射方法，则会新建此对象

1.1.5 searchMethods

  1. private static Method searchMethods(Method[] methods,
  2.                                         String name,
  3.                                         Class<?>[] parameterTypes)
  4.     {
  5.         Method res = null;
  6.         String internedName = name.intern();
  7.         for (int i = 0; i < methods.length; i++) {
  8.             Method m = methods[i];
  9.             if (m.getName() == internedName
  10.                 && arrayContentsEq(parameterTypes, m.getParameterTypes())
  11.                 && (res == null
  12.                     || res.getReturnType().isAssignableFrom(m.getReturnType())))
  13.                 res = m;
  14.         }
  16.         return (res == null ? res : getReflectionFactory().copyMethod(res));
  17.     }

如果找到一个匹配的Method，则重新copy一份返回

1.2 getDeclaredMethod

  1.  public Method getDeclaredMethod(String name, Class<?>... parameterTypes)
  2.         throws NoSuchMethodException, SecurityException {
  3.         checkMemberAccess(Member.DECLARED, Reflection.getCallerClass(), true);
  4.         Method method = searchMethods(privateGetDeclaredMethods(false), name, parameterTypes);
  5.         if (method == null) {
  6.             throw new NoSuchMethodException(getName() + "." + name + argumentTypesToString(parameterTypes));
  7.         }
  8.         return method;
  9.     }

privateGetDeclaredMethods(false)入参传false，其他和getMethod()基本一致