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@@ -0,0 +1,125 @@
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+package org.jetlinks.community.standalone.utils;
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+
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+import sun.reflect.ConstructorAccessor;
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+import sun.reflect.FieldAccessor;
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+import sun.reflect.ReflectionFactory;
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+
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+import java.lang.reflect.Array;
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+import java.lang.reflect.Modifier;
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+import java.util.*;
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+import java.lang.reflect.AccessibleObject;
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+import java.lang.reflect.Field;
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+
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+/**
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+ * @author lifang
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+ * @version 1.0.0
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+ * @ClassName EnumsUtils.java
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+ * @Description TODO
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+ * @createTime 2021年08月27日 11:32:00
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+ */
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+public class EnumsUtils {
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+ @SuppressWarnings("unchecked")
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+ public static <T extends Enum<?>> void addEnum(Class<T> enumType, String enumName,Class<?>[] paramClass,Object[] paramValue) {
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+
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+ // 0. Sanity checks
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+ if (!Enum.class.isAssignableFrom(enumType)) {
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+ throw new RuntimeException("class " + enumType + " is not an instance of Enum");
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+ }
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+
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+ // 1. Lookup "$VALUES" holder in enum class and get previous enum instances
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+ Field valuesField = null;
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+ Field[] fields = enumType.getDeclaredFields();
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+ for (Field field : fields) {
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+ if (field.getName().contains("$VALUES")) {
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+ valuesField = field;
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+ break;
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+ }
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+ }
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+ AccessibleObject.setAccessible(new Field[] { valuesField }, true);
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+
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+ try {
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+
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+ // 2. Copy it
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+ T[] previousValues = (T[]) valuesField.get(enumType);
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+ List<T> values = new ArrayList<T>(Arrays.asList(previousValues));
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+
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+ // 3. build new enum
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+ T newValue = (T) makeEnum(enumType, // The target enum class
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+ enumName, // THE NEW ENUM INSTANCE TO BE DYNAMICALLY ADDED
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+ values.size(),
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+ //new Class<?>[] {}, // could be used to pass values to the enum constuctor if needed
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+ paramClass,
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+ //new Object[] {}
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+ paramValue
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+ ); // could be used to pass values to the enum constuctor if needed
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+
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+ // 4. add new value
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+ values.add(newValue);
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+ Object object=values.toArray((T[]) Array.newInstance(enumType, 0));
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+ // 5. Set new values field
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+ setFailsafeFieldValue(valuesField, null, object);
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+
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+ // 6. Clean enum cache
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+ cleanEnumCache(enumType);
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+
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+ } catch (Exception e) {
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+ e.printStackTrace();
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+ throw new RuntimeException(e.getMessage(), e);
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+ }
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+ }
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+
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+ private static Object makeEnum(Class<?> enumClass, String value, int ordinal, Class<?>[] additionalTypes,
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+ Object[] additionalValues) throws Exception {
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+ Object[] parms = new Object[additionalValues.length + 2];
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+ parms[0] = value;
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+ parms[1] = Integer.valueOf(ordinal);
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+ System.arraycopy(additionalValues, 0, parms, 2, additionalValues.length);
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+ return enumClass.cast(getConstructorAccessor(enumClass, additionalTypes).newInstance(parms));
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+ }
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+
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+ private static ReflectionFactory reflectionFactory = ReflectionFactory.getReflectionFactory();
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+ private static void setFailsafeFieldValue(Field field, Object target, Object value) throws NoSuchFieldException,
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+ IllegalAccessException {
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+
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+ // let's make the field accessible
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+ field.setAccessible(true);
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+ // next we change the modifier in the Field instance to
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+ // not be final anymore, thus tricking reflection into
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+ // letting us modify the static final field
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+ Field modifiersField = Field.class.getDeclaredField("modifiers");
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+ modifiersField.setAccessible(true);
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+ int modifiers = modifiersField.getInt(field);
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+
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+ // blank out the final bit in the modifiers int
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+ modifiers &= ~Modifier.FINAL;
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+ modifiersField.setInt(field, modifiers);
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+
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+ FieldAccessor fa = reflectionFactory.newFieldAccessor(field, false);
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+ fa.set(target, value);
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+ }
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+ private static void blankField(Class<?> enumClass, String fieldName) throws NoSuchFieldException,
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+ IllegalAccessException {
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+ for (Field field : Class.class.getDeclaredFields()) {
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+ if (field.getName().contains(fieldName)) {
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+ AccessibleObject.setAccessible(new Field[] { field }, true);
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+ setFailsafeFieldValue(field, enumClass, null);
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+ break;
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+ }
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+ }
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+ }
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+
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+ private static void cleanEnumCache(Class<?> enumClass) throws NoSuchFieldException, IllegalAccessException {
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+ blankField(enumClass, "enumConstantDirectory"); // Sun (Oracle?!?) JDK 1.5/6
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+ blankField(enumClass, "enumConstants"); // IBM JDK
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+ }
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+
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+ private static ConstructorAccessor getConstructorAccessor(Class<?> enumClass, Class<?>[] additionalParameterTypes)
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+ throws NoSuchMethodException {
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+ Class<?>[] parameterTypes = new Class[additionalParameterTypes.length + 2];
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+ parameterTypes[0] = String.class;
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+ parameterTypes[1] = int.class;
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+ System.arraycopy(additionalParameterTypes, 0, parameterTypes, 2, additionalParameterTypes.length);
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+ return reflectionFactory.newConstructorAccessor(enumClass.getDeclaredConstructor(parameterTypes));
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+
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+ }
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+}
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