From eef7943d8a6f0688acff8eb705b3bcb8e7fbaab6 Mon Sep 17 00:00:00 2001 From: Looly Date: Wed, 21 Sep 2022 18:31:31 +0800 Subject: [PATCH] =?UTF-8?q?ModifierUtil=E5=92=8CReflectUtil=E5=A2=9E?= =?UTF-8?q?=E5=8A=A0removeFinalModify?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- CHANGELOG.md | 3 +- .../cn/hutool/core/util/ModifierUtil.java | 54 +++++++++++++++++++ .../java/cn/hutool/core/util/ReflectUtil.java | 22 +------- .../cn/hutool/core/util/ReflectUtilTest.java | 28 +++++----- 4 files changed, 71 insertions(+), 36 deletions(-) diff --git a/CHANGELOG.md b/CHANGELOG.md index 5c0aead78..61b139015 100755 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -3,12 +3,13 @@ ------------------------------------------------------------------------------------------------------------- -# 5.8.8.M1 (2022-09-20) +# 5.8.8.M1 (2022-09-21) ### 🐣新特性 * 【core 】 StreamUtil.of方法新增对 Iterator 支持；StreamUtil.of(Iterable) 方法优化（pr#807@Gitee） * 【core 】 增加.wgt格式的MimeType（pr#2617@Github） * 【core 】 EnumUtil.getBy增加带默认值重载（issue#I5RZU6@Gitee） +* 【core 】 ModifierUtil和ReflectUtil增加removeFinalModify（pr#810@Gitee） ### 🐞Bug修复 * 【core 】 修复FileNameUtil.cleanInvalid无法去除换行符问题（issue#I5RMZV@Gitee） diff --git a/hutool-core/src/main/java/cn/hutool/core/util/ModifierUtil.java b/hutool-core/src/main/java/cn/hutool/core/util/ModifierUtil.java index dec42bed0..224950a94 100644 --- a/hutool-core/src/main/java/cn/hutool/core/util/ModifierUtil.java +++ b/hutool-core/src/main/java/cn/hutool/core/util/ModifierUtil.java @@ -1,5 +1,7 @@ package cn.hutool.core.util; +import cn.hutool.core.exceptions.UtilException; + import java.lang.reflect.Constructor; import java.lang.reflect.Field; import java.lang.reflect.Method; @@ -262,6 +264,58 @@ public class ModifierUtil { public static boolean isAbstract(Method method) { return hasModifier(method, ModifierType.ABSTRACT); } + + /** + * 设置final的field字段可以被修改 + *

+ * 只要不会被编译器内联优化的 final 属性就可以通过反射有效的进行修改 -- 修改后代码中可使用到新的值; + *
+ *

以下属性，编译器会内联优化，无法通过反射修改：

+ * + *

以下属性，可以通过反射修改：

+ * + *

+ * + * //示例，移除final修饰符 + * class JdbcDialects {private static final List dialects = new ArrayList<>();} + * Field field = ReflectUtil.getField(JdbcDialects.class, fieldName); + * ReflectUtil.removeFinalModify(field); + * ReflectUtil.setFieldValue(JdbcDialects.class, fieldName, dialects); + * + * @param field 被修改的field，不可以为空 + * @throws UtilException IllegalAccessException等异常包装 + * @since 5.8.8 + * @author dazer + */ + public static void removeFinalModify(Field field) { + if (field != null) { + if (hasModifier(field, ModifierUtil.ModifierType.FINAL)) { + //将字段的访问权限设为true：即去除private修饰符的影响 + if (false == field.isAccessible()) { + field.setAccessible(true); + } + try { + //去除final修饰符的影响，将字段设为可修改的 + final Field modifiersField = Field.class.getDeclaredField("modifiers"); + //Field 的 modifiers 是私有的 + modifiersField.setAccessible(true); + //& ：位与运算符，按位与； 运算规则：两个数都转为二进制，然后从高位开始比较，如果两个数都为1则为1，否则为0。 + //~ ：位非运算符，按位取反；运算规则：转成二进制，如果位为0，结果是1，如果位为1，结果是0. + modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL); + } catch (final NoSuchFieldException | IllegalAccessException e) { + //内部，工具类，基本不抛出异常 + throw new UtilException(e, "IllegalAccess for {}.{}", field.getDeclaringClass(), field.getName()); + } + } + } + } //-------------------------------------------------------------------------------------------------------- Private method start /** diff --git a/hutool-core/src/main/java/cn/hutool/core/util/ReflectUtil.java b/hutool-core/src/main/java/cn/hutool/core/util/ReflectUtil.java index d56e01966..f61027b0a 100755 --- a/hutool-core/src/main/java/cn/hutool/core/util/ReflectUtil.java +++ b/hutool-core/src/main/java/cn/hutool/core/util/ReflectUtil.java @@ -9,7 +9,6 @@ import cn.hutool.core.exceptions.InvocationTargetRuntimeException; import cn.hutool.core.exceptions.UtilException; import cn.hutool.core.lang.Assert; import cn.hutool.core.lang.Filter; -import java.lang.reflect.Modifier; import cn.hutool.core.lang.reflect.MethodHandleUtil; import cn.hutool.core.map.MapUtil; import cn.hutool.core.map.WeakConcurrentMap; @@ -1141,26 +1140,7 @@ public class ReflectUtil { * @author dazer */ public static void removeFinalModify(Field field) { - if (field != null) { - if (ModifierUtil.hasModifier(field, ModifierUtil.ModifierType.FINAL)) { - //将字段的访问权限设为true：即去除private修饰符的影响 - if (!field.isAccessible()) { - field.setAccessible(true); - } - try { - //去除final修饰符的影响，将字段设为可修改的 - Field modifiersField = Field.class.getDeclaredField("modifiers"); - //Field 的 modifiers 是私有的 - modifiersField.setAccessible(true); - //& ：位与运算符，按位与； 运算规则：两个数都转为二进制，然后从高位开始比较，如果两个数都为1则为1，否则为0。 - //~ ：位非运算符，按位取反；运算规则：转成二进制，如果位为0，结果是1，如果位为1，结果是0. - modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL); - } catch (NoSuchFieldException | IllegalAccessException e) { - //内部，工具类，基本不抛出异常 - throw new UtilException(e, "IllegalAccess for {}.{}", field.getDeclaringClass(), field.getName()); - } - } - } + ModifierUtil.removeFinalModify(field); } /** diff --git a/hutool-core/src/test/java/cn/hutool/core/util/ReflectUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/util/ReflectUtilTest.java index 6170ec61b..3b82a70a6 100755 --- a/hutool-core/src/test/java/cn/hutool/core/util/ReflectUtilTest.java +++ b/hutool-core/src/test/java/cn/hutool/core/util/ReflectUtilTest.java @@ -74,7 +74,7 @@ public class ReflectUtilTest { @Test public void getFieldTest() { // 能够获取到父类字段 - Field privateField = ReflectUtil.getField(TestSubClass.class, "privateField"); + final Field privateField = ReflectUtil.getField(TestSubClass.class, "privateField"); Assert.assertNotNull(privateField); } @@ -87,14 +87,14 @@ public class ReflectUtilTest { @Test public void setFieldTest() { - TestClass testClass = new TestClass(); + final TestClass testClass = new TestClass(); ReflectUtil.setFieldValue(testClass, "a", "111"); Assert.assertEquals(111, testClass.getA()); } @Test public void invokeTest() { - TestClass testClass = new TestClass(); + final TestClass testClass = new TestClass(); ReflectUtil.invoke(testClass, "setA", 10); Assert.assertEquals(10, testClass.getA()); } @@ -155,7 +155,7 @@ public class ReflectUtilTest { private String n; } - public static Method getMethodWithReturnTypeCheck(Class clazz, boolean ignoreCase, String methodName, Class... paramTypes) throws SecurityException { + public static Method getMethodWithReturnTypeCheck(final Class clazz, final boolean ignoreCase, final String methodName, final Class... paramTypes) throws SecurityException { if (null == clazz || StrUtil.isBlank(methodName)) { return null; } @@ -163,7 +163,7 @@ public class ReflectUtilTest { Method res = null; final Method[] methods = ReflectUtil.getMethods(clazz); if (ArrayUtil.isNotEmpty(methods)) { - for (Method method : methods) { + for (final Method method : methods) { if (StrUtil.equals(methodName, method.getName(), ignoreCase) && ClassUtil.isAllAssignableFrom(method.getParameterTypes(), paramTypes) && (res == null @@ -252,22 +252,22 @@ public class ReflectUtilTest { @Test public void newInstanceIfPossibleTest(){ //noinspection ConstantConditions - int intValue = ReflectUtil.newInstanceIfPossible(int.class); + final int intValue = ReflectUtil.newInstanceIfPossible(int.class); Assert.assertEquals(0, intValue); - Integer integer = ReflectUtil.newInstanceIfPossible(Integer.class); + final Integer integer = ReflectUtil.newInstanceIfPossible(Integer.class); Assert.assertEquals(new Integer(0), integer); - Map map = ReflectUtil.newInstanceIfPossible(Map.class); + final Map map = ReflectUtil.newInstanceIfPossible(Map.class); Assert.assertNotNull(map); - Collection collection = ReflectUtil.newInstanceIfPossible(Collection.class); + final Collection collection = ReflectUtil.newInstanceIfPossible(Collection.class); Assert.assertNotNull(collection); - Week week = ReflectUtil.newInstanceIfPossible(Week.class); + final Week week = ReflectUtil.newInstanceIfPossible(Week.class); Assert.assertEquals(Week.SUNDAY, week); - int[] intArray = ReflectUtil.newInstanceIfPossible(int[].class); + final int[] intArray = ReflectUtil.newInstanceIfPossible(int[].class); Assert.assertArrayEquals(new int[0], intArray); } @@ -277,8 +277,8 @@ public class ReflectUtilTest { } @Test - public void setFieldValueTest() { - String fieldName = "DIALECTS"; + public void setFieldValueWithFinalTest() { + final String fieldName = "DIALECTS"; final List dialects = Arrays.asList( 1, @@ -286,7 +286,7 @@ public class ReflectUtilTest { 3, 99 ); - Field field = ReflectUtil.getField(JdbcDialects.class, fieldName); + final Field field = ReflectUtil.getField(JdbcDialects.class, fieldName); ReflectUtil.removeFinalModify(field); ReflectUtil.setFieldValue(JdbcDialects.class, fieldName, dialects);