肉山谷英雄传说新手任务登录英文网站怎么做,装修网站建设网,山西网站建设费用,局域网wordpress文章目录 前言UUID 处理的更改正则表达式的更改结束 前言 Android 14 已经出来好久好久了… 今天其他的暂且不论#xff0c;单纯的讲一下 OpenJDK 17 更新的两点变更#xff08;扒源代码#xff09;~ 对正则表达式的更改UUID 处理 首先#xff0c;正则表达式的更改单纯的讲一下 OpenJDK 17 更新的两点变更扒源代码~ 对正则表达式的更改UUID 处理 首先正则表达式的更改现在为了更严格地遵循 OpenJDK 的语义不允许无效的组引用。您可能会看到 java.util.regex.Matcher 类抛出 IllegalArgumentException 的新情况因此请务必测试应用中使用正则表达式的情形。如需在测试期间启用或停用此变更请使用兼容性框架工具切换 DISALLOW_INVALID_GROUP_REFERENCE 标志。 其次UUID 处理现在验证输入参数时java.util.UUID.fromString() 方法会执行更严格的检查因此您可能会在反序列化期间看到 IllegalArgumentException。如需在测试期间启用或停用此变更请使用兼容性框架工具切换 ENABLE_STRICT_VALIDATION 标志。 巴拉巴拉以上是官网的言论诸君可以看官方的描述地址 UUID 处理的更改 原有代码逻辑~ /*** Creates a {code UUID} from the string standard representation as* described in the {link #toString} method.** param name* A string that specifies a {code UUID}** return A {code UUID} with the specified value** throws IllegalArgumentException* If name does not conform to the string representation as* described in {link #toString}**/public static UUID fromString(String name) {String[] components name.split(-);if (components.length ! 5)//仅会判断以-分割的数组长度是否等于5来抛出异常throw new IllegalArgumentException(Invalid UUID string: name);for (int i0; i5; i)components[i] 0xcomponents[i];long mostSigBits Long.decode(components[0]).longValue();mostSigBits 16;mostSigBits | Long.decode(components[1]).longValue();mostSigBits 16;mostSigBits | Long.decode(components[2]).longValue();long leastSigBits Long.decode(components[3]).longValue();leastSigBits 48;leastSigBits | Long.decode(components[4]).longValue();return new UUID(mostSigBits, leastSigBits);}新代码逻辑~ /*** Creates a {code UUID} from the string standard representation as* described in the {link #toString} method.** param name* A string that specifies a {code UUID}** return A {code UUID} with the specified value** throws IllegalArgumentException* If name does not conform to the string representation as* described in {link #toString}**/public static UUID fromString(String name) {// BEGIN Android-changed: Java 8 behaviour is more lenient and the new implementation// might break apps (b/254278943).// Using old implementation for apps targeting Android older than U.// 取反 如果设备的sdk版本大于等于 UPSIDE_DOWN_CAKE34的话且启用严格验证if (!(VMRuntime.getSdkVersion() VersionCodes.UPSIDE_DOWN_CAKE Compatibility.isChangeEnabled(ENABLE_STRICT_VALIDATION))) {return fromStringJava8(name);}//如果小于或者没开启严格验证则执行其他的验证 return fromStringCurrentJava(name);// END Android-changed: Java 8 behaviour is more lenient and the new implementation// might break apps (b/254278943).}如下是java8 的判断方式跟原来一致 /*** Extracted for testing purposes only.* hide*/public static UUID fromStringJava8(String name) {String[] components name.split(-);if (components.length ! 5)throw new IllegalArgumentException(Invalid UUID string: name);for (int i0; i5; i)components[i] 0xcomponents[i];long mostSigBits Long.decode(components[0]).longValue();mostSigBits 16;mostSigBits | Long.decode(components[1]).longValue();mostSigBits 16;mostSigBits | Long.decode(components[2]).longValue();long leastSigBits Long.decode(components[3]).longValue();leastSigBits 48;leastSigBits | Long.decode(components[4]).longValue();return new UUID(mostSigBits, leastSigBits);}如下是执行34或者开启严格验证的方法 /*** Extracted for testing purposes only.* hide*/public static UUID fromStringCurrentJava(String name) {if (name.length() 36) {char ch1 name.charAt(8);char ch2 name.charAt(13);char ch3 name.charAt(18);char ch4 name.charAt(23);if (ch1 - ch2 - ch3 - ch4 -) {long msb1 parse4Nibbles(name, 0);long msb2 parse4Nibbles(name, 4);long msb3 parse4Nibbles(name, 9);long msb4 parse4Nibbles(name, 14);long lsb1 parse4Nibbles(name, 19);long lsb2 parse4Nibbles(name, 24);long lsb3 parse4Nibbles(name, 28);long lsb4 parse4Nibbles(name, 32);if ((msb1 | msb2 | msb3 | msb4 | lsb1 | lsb2 | lsb3 | lsb4) 0) {return new UUID(msb1 48 | msb2 32 | msb3 16 | msb4,lsb1 48 | lsb2 32 | lsb3 16 | lsb4);}}}return fromString1(name);}private static UUID fromString1(String name) {int len name.length();if (len 36) {throw new IllegalArgumentException(UUID string too large);}int dash1 name.indexOf(-, 0);int dash2 name.indexOf(-, dash1 1);int dash3 name.indexOf(-, dash2 1);int dash4 name.indexOf(-, dash3 1);int dash5 name.indexOf(-, dash4 1);// For any valid input, dash1 through dash4 will be positive and dash5// negative, but its enough to check dash4 and dash5:// - if dash1 is -1, dash4 will be -1// - if dash1 is positive but dash2 is -1, dash4 will be -1// - if dash1 and dash2 is positive, dash3 will be -1, dash4 will be// positive, but so will dash5if (dash4 0 || dash5 0) {throw new IllegalArgumentException(Invalid UUID string: name);}long mostSigBits Long.parseLong(name, 0, dash1, 16) 0xffffffffL;mostSigBits 16;mostSigBits | Long.parseLong(name, dash1 1, dash2, 16) 0xffffL;mostSigBits 16;mostSigBits | Long.parseLong(name, dash2 1, dash3, 16) 0xffffL;long leastSigBits Long.parseLong(name, dash3 1, dash4, 16) 0xffffL;leastSigBits 48;leastSigBits | Long.parseLong(name, dash4 1, len, 16) 0xffffffffffffL;return new UUID(mostSigBits, leastSigBits);} 解析 从代码的角度看起来是多了好多验证梳理一下 1. 判断是否34sdk版本且未开启严格验证的情况下还是按照原有代码执行仅仅判断 以-分割的数组长度是否等于5若不等于5则主动抛出异常2. 如果sdk版本大于等于34且开启了严格验证则会执行fromStringCurrentJava fromString1方法fromStringCurrentJava方法中没有主动抛出异常的代码判断长度是否36不等于则执行 fromString1若等于则继续执行获取字符串下标8、13、18、23的值若这四个值不等于 - 则执行 fromString1 在fromString1 方法中传递的字符串长度不得大于36若超出则主动抛异常继续判断对于任何有效输入dash1 到 dash4 将为正数dash5 将为正数负数但检查 dash4 和 dash5 就足够了 若是dash4小于0dash5大于等于0则主动抛出异常正则表达式的更改 原有代码逻辑~ /*** Attempts to match the entire region against the pattern.** p If the match succeeds then more information can be obtained via the* ttstart/tt, ttend/tt, and ttgroup/tt methods. /p** return tttrue/tt if, and only if, the entire region sequence* matches this matchers pattern*/public boolean matches() {synchronized (this) {matchFound nativeMatcher.matches(groups);}return matchFound;新代码逻辑~ /*** Attempts to match the entire region against the pattern.** p If the match succeeds then more information can be obtained via the* {code start}, {code end}, and {code group} methods. /p** return {code true} if, and only if, the entire region sequence* matches this matchers pattern*/public boolean matches() {synchronized (this) {matchFound nativeMatcher.matches(groups);}//主要增加一个这个modCount;return matchFound;} modCount的描述 记录该匹配器状态被修改的次数 /*** Number of times this matchers state has been modified*/int modCount;结束 不是我说哈你都是系统代码了还起个 fromString1 这样的方法名称丢人不~ 就这有问题私聊我~ 再会~