mybatis

写底层通用方法/框架，借鉴方法

PropertyNamer

// getxxx setxxx 转属性名 

  public static String methodToProperty(String name) {
    if (name.startsWith("is")) {
      name = name.substring(2);
    } else if (name.startsWith("get") || name.startsWith("set")) {
      name = name.substring(3);
    } else {
      throw new ReflectionException("Error parsing property name '" + name + "'.  Didn't start with 'is', 'get' or 'set'.");
    }

    if (name.length() == 1 || (name.length() > 1 && !Character.isUpperCase(name.charAt(1)))) {
      name = name.substring(0, 1).toLowerCase(Locale.ENGLISH) + name.substring(1);
    }

    return name;
  }

  public static boolean isProperty(String name) {
    return isGetter(name) || isSetter(name);
  }

  public static boolean isGetter(String name) {
    return (name.startsWith("get") && name.length() > 3) || (name.startsWith("is") && name.length() > 2);
  }

  public static boolean isSetter(String name) {
    return name.startsWith("set") && name.length() > 3;
  }

PropertyCopier

  public static void copyBeanProperties(Class type, Object sourceBean, Object destinationBean) {
    Class parent = type;
    while (parent != null) {
      final Field[] fields = parent.getDeclaredFields();
      for (Field field : fields) {
        try {
          try {
            field.set(destinationBean, field.get(sourceBean));
          } catch (IllegalAccessException e) {
            if (Reflector.canControlMemberAccessible()) {
              field.setAccessible(true);
              field.set(destinationBean, field.get(sourceBean));
            } else {
              throw e;
            }
          }
        } catch (Exception e) {
          // Nothing useful to do, will only fail on final fields, which will be ignored.
        }
      }
      parent = parent.getSuperclass();
    }
  }

  private void addSetMethods(Method[] methods) {
    Map> conflictingSetters = new HashMap<>();
    Arrays.stream(methods).filter(m -> m.getParameterTypes().length == 1 && PropertyNamer.isSetter(m.getName()))
      .forEach(m -> addMethodConflict(conflictingSetters, PropertyNamer.methodToProperty(m.getName()), m));
    resolveSetterConflicts(conflictingSetters);
  }

  private void addMethodConflict(Map> conflictingMethods, String name, Method method) {
    if (isValidPropertyName(name)) {
      List list = MapUtil.computeIfAbsent(conflictingMethods, name, k -> new ArrayList<>());
      list.add(method);
    }
  }

## MapUtil      map里套 list， get时，list 有则返回，无则 初始化
public class MapUtil {

  public static  V computeIfAbsent(Map map, K key, Function mappingFunction) {
    V value = map.get(key);
    if (value != null) {
      return value;
    }
    return map.computeIfAbsent(key, mappingFunction);
  }

  /**
   * Map.entry(key, value) alternative for Java 8.
   */
  public static  Entry entry(K key, V value) {
    return new AbstractMap.SimpleImmutableEntry<>(key, value);
  }

  private MapUtil() {
    super();
  }
}

二级目录

借用spring 的解析器，解析 #{ 和 }

三级目录