{"id":314401,"date":"2024-05-20T23:32:21","date_gmt":"2024-05-20T15:32:21","guid":{"rendered":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/314401.html"},"modified":"2024-05-20T23:32:27","modified_gmt":"2024-05-20T15:32:27","slug":"java-%e8%8e%b7%e5%8f%96%e9%9a%8f%e6%9c%ba%e6%95%b0%e7%9a%84%e6%96%b9%e6%b3%95%e6%9c%89%e5%93%aa%e4%ba%9b","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/ask-ask\/314401.html","title":{"rendered":"Java \u83b7\u53d6\u968f\u673a\u6570\u7684\u65b9\u6cd5\u6709\u54ea\u4e9b"},"content":{"rendered":"

\"Java<\/p>\n

Java\u83b7\u53d6\u968f\u673a\u6570\u7684\u65b9\u6cd5\u4e3b\u8981\u5305\u62ec\uff1a<\/strong> Math.random()<\/code><\/strong>\u3001Random<\/code> \u7c7b<\/strong>\u3001ThreadLocalRandom<\/code> \u7c7b<\/strong>\u3001SecureRandom<\/code> \u7c7b<\/strong> \u548c SplittableRandom<\/code> \u7c7b<\/strong>\u3002Math.random()<\/code><\/strong> \u662f\u83b7\u53d6\u968f\u673a\u6570\u7684\u6700\u7b80\u5355\u65b9\u6cd5\uff0c\u5b83\u8fd4\u56de\u4e00\u4e2a\u4ecb\u4e8e0.0\u52301.0\u4e4b\u95f4\u7684\u53cc\u7cbe\u5ea6\u968f\u673a\u6570\u3002\u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u5c06\u8be6\u7ec6\u63a2\u8ba8\u6bcf\u79cd\u65b9\u6cd5\u7684\u7279\u70b9\u548c\u4f7f\u7528\u573a\u666f\u3002<\/p>\n<\/p>\n

\u4e00\u3001\u4f7f\u7528 Math.random()<\/code><\/h2>\n<\/p>\n

Math.random()<\/code><\/strong> \u65b9\u6cd5\u5728Java\u4e2d\u662f\u6700\u57fa\u672c\u7684\u968f\u673a\u6570\u751f\u6210\u65b9\u5f0f\u3002\u5b83\u4e0d\u9700\u8981\u5b9e\u4f8b\u5316\u4efb\u4f55\u5bf9\u8c61\uff0c\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528\uff0c\u5e76\u4e14\u8fd4\u56de\u4e00\u4e2a0\u52301\u4e4b\u95f4\u7684\u53cc\u7cbe\u5ea6\u6d6e\u70b9\u6570\u3002Math.random()<\/code><\/strong> \u901a\u5e38\u7528\u4e8e\u751f\u6210\u7b80\u5355\u7684\u968f\u673a\u6570\uff0c\u4f46\u5728\u9700\u8981\u66f4\u9ad8\u7ea7\u522b\u7684\u968f\u673a\u6027\u6216\u5927\u91cf\u968f\u673a\u6570\u65f6\uff0c\u53ef\u80fd\u4e0d\u662f\u6700\u4f73\u9009\u62e9\u3002<\/p>\n<\/p>\n

\u83b7\u53d6\u57fa\u672c\u968f\u673a\u6570<\/h3>\n<\/p>\n

double randomNumber = Math.random();<\/p>\n
System.out.println(randomNumber); \/\/ \u8f93\u51fa\u4ecb\u4e8e0.0\u52301.0\u4e4b\u95f4\u7684\u968f\u673a\u6570<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u751f\u6210\u8303\u56f4\u5185\u7684\u968f\u673a\u6570<\/h3>\n<\/p>\n
\u4f60\u53ef\u4ee5\u901a\u8fc7\u7b80\u5355\u7684\u6570\u5b66\u53d8\u6362\uff0c\u5f97\u5230\u4e00\u4e2a\u7279\u5b9a\u8303\u56f4\u5185\u7684\u968f\u673a\u6570\uff1a<\/p>\n<\/p>\n
int min = 1;<\/p>\n
int max = 10;<\/p>\n
int rangeRandomNumber = min + (int)(Math.random() * ((max - min) + 1));<\/p>\n
System.out.println(rangeRandomNumber); \/\/ \u8f93\u51fa\u4ecb\u4e8e1\u523010\u4e4b\u95f4\u7684\u968f\u673a\u6574\u6570<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e8c\u3001Random<\/code> \u7c7b\u7684\u5e94\u7528<\/h2>\n<\/p>\n
Random<\/code> \u7c7b\u4f4d\u4e8ejava.util<\/code>\u5305\u4e2d\uff0c\u63d0\u4f9b\u4e86\u6bd4Math.random()<\/code>\u65b9\u6cd5\u66f4\u52a0\u4e30\u5bcc\u7684\u968f\u673a\u6570\u751f\u6210\u5668\u529f\u80fd\uff0c\u5305\u62ec\u751f\u6210\u4e0d\u540c\u6570\u636e\u7c7b\u578b\u7684\u968f\u673a\u6570\u3002Random<\/code> \u7c7b<\/strong> \u53ef\u751f\u6210\u5747\u5300\u5206\u5e03\u7684\u968f\u673a\u6570\uff0c\u800c\u4e14\u53ef\u4ee5\u6301\u6709\u79cd\u5b50\uff08seed\uff09\uff0c\u5b83\u4eec\u6839\u636e\u79cd\u5b50\u503c\u4ea7\u751f\u53ef\u9884\u6d4b\u7684\u968f\u673a\u6570\u5e8f\u5217\u3002<\/p>\n<\/p>\n
\u6784\u9020\u968f\u673a\u6570\u751f\u6210\u5668<\/h3>\n<\/p>\n
Random random = new Random(); \/\/ \u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u968f\u673a\u6570\u751f\u6210\u5668<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u751f\u6210\u7279\u5b9a\u7c7b\u578b\u7684\u968f\u673a\u6570<\/h3>\n<\/p>\n
Random<\/code> \u7c7b\u53ef\u4ee5\u751f\u6210\u5404\u79cd\u6570\u636e\u7c7b\u578b\u7684\u968f\u673a\u6570\uff0c\u4f8b\u5982\u6574\u6570\u3001\u6d6e\u70b9\u6570\u7b49\uff1a<\/p>\n<\/p>\n
int intRandom = random.nextInt(); \/\/ \u751f\u6210\u968f\u673a\u6574\u6570<\/p>\n
int intBoundedRandom = random.nextInt(100); \/\/ \u751f\u62100(\u5305\u542b)\u5230100(\u4e0d\u5305\u542b)\u4e4b\u95f4\u7684\u6574\u6570<\/p>\n
long longRandom = random.nextLong(); \/\/ \u751f\u6210\u968f\u673a\u957f\u6574\u578b\u6570<\/p>\n
boolean booleanRandom = random.nextBoolean(); \/\/ \u751f\u6210\u968f\u673a\u5e03\u5c14\u503c<\/p>\n
float floatRandom = random.nextFloat(); \/\/ \u751f\u62100.0\u52301.0\u4e4b\u95f4\u7684\u6d6e\u70b9\u6570<\/p>\n
double doubleRandom = random.nextDouble(); \/\/ \u751f\u62100.0\u52301.0\u4e4b\u95f4\u7684\u53cc\u7cbe\u5ea6\u6570<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e09\u3001ThreadLocalRandom<\/code> \u7c7b\u7684\u4f7f\u7528<\/h2>\n<\/p>\n
ThreadLocalRandom<\/code> \u662fJava 7\u4e2d\u5f15\u5165\u7684\uff0c\u4e13\u95e8\u4e3a\u591a\u7ebf\u7a0b\u73af\u5883\u8bbe\u8ba1\u7684\u968f\u673a\u6570\u751f\u6210\u5668\u3002\u5b83\u5728\u5e76\u53d1\u7a0b\u5e8f\u4e2d\u4f1a\u6bd4\u5171\u4eab\u7684Random<\/code> \u5b9e\u4f8b\u63d0\u4f9b\u66f4\u597d\u7684\u6027\u80fd\u3002ThreadLocalRandom<\/code><\/strong> \u4e0d\u80fd\u76f4\u63a5\u5b9e\u4f8b\u5316\uff0c\u800c\u662f\u901a\u8fc7\u5f53\u524d\u7ebf\u7a0b\u7684ThreadLocalRandom.current()<\/code>\u65b9\u6cd5\u8bbf\u95ee\u3002<\/p>\n<\/p>\n
\u83b7\u53d6ThreadLocalRandom<\/code> \u5b9e\u4f8b<\/h3>\n<\/p>\n
ThreadLocalRandom threadLocalRandom = ThreadLocalRandom.current(); \/\/ \u83b7\u53d6\u5f53\u524d\u7ebf\u7a0b\u7684\u968f\u673a\u6570\u751f\u6210\u5668\u5b9e\u4f8b<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u751f\u6210\u968f\u673a\u6570<\/h3>\n<\/p>\n
ThreadLocalRandom<\/code> \u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684API\u6765\u751f\u6210\u4e0d\u540c\u8303\u56f4\u548c\u7c7b\u578b\u7684\u968f\u673a\u6570\uff1a<\/p>\n<\/p>\n
int tlIntRandom = threadLocalRandom.nextInt(10, 50); \/\/ \u751f\u621010(\u5305\u542b)\u523050(\u4e0d\u5305\u542b)\u4e4b\u95f4\u7684\u968f\u673a\u6574\u6570<\/p>\n
double tlDoubleRandom = threadLocalRandom.nextDouble(20.5, 50.5); \/\/ \u751f\u621020.5\u523050.5\u4e4b\u95f4\u7684\u968f\u673a\u53cc\u7cbe\u5ea6\u6570<\/p>\n
long tlLongRandom = threadLocalRandom.nextLong(100L, 1000L); \/\/ \u751f\u6210100(\u5305\u542b)\u52301000(\u4e0d\u5305\u542b)\u4e4b\u95f4\u7684\u968f\u673a\u957f\u6574\u578b\u6570<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u56db\u3001\u5229\u7528 SecureRandom<\/code> \u7c7b<\/h2>\n<\/p>\n
SecureRandom<\/code> \u7c7b\u7ee7\u627f\u81eaRandom<\/code> \u7c7b\uff0c\u63d0\u4f9b\u4e86\u52a0\u5bc6\u5f3a\u968f\u673a\u6570\u751f\u6210\u5668 (CSPRNG)\u3002\u7528\u4e8e\u9700\u8981\u9ad8\u5f3a\u5ea6\u5b89\u5168\u548c\u52a0\u5bc6\u7684\u5e94\u7528\u573a\u666f\uff0c\u6bd4\u5982\u5728\u751f\u6210HTTPS\u7684\u4f1a\u8bdd\u5bc6\u94a5\u6216\u8005\u751f\u6210\u5bc6\u7801\u5b66\u4e2d\u7684\u975e\u5bf9\u79f0\u5bc6\u94a5\u5bf9\u3002<\/p>\n<\/p>\n
\u6784\u9020SecureRandom<\/code> \u5b9e\u4f8b<\/h3>\n<\/p>\n
SecureRandom secureRandom = new SecureRandom(); \/\/ \u521b\u5efa\u4e00\u4e2a\u9ed8\u8ba4\u7684\u5b89\u5168\u968f\u673a\u6570\u751f\u6210\u5668<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u751f\u6210\u5b89\u5168\u968f\u673a\u6570<\/h3>\n<\/p>\n
SecureRandom<\/code> \u7c7b\u540c\u6837\u53ef\u4ee5\u751f\u6210\u5404\u79cd\u6570\u636e\u7c7b\u578b\u7684\u968f\u673a\u6570\uff0c\u8fd9\u4e9b\u968f\u673a\u6570\u9002\u5408\u7528\u4e8e\u5b89\u5168\u654f\u611f\u7684\u5e94\u7528\uff1a<\/p>\n<\/p>\n
byte[] bytes = new byte[64];<\/p>\n
secureRandom.nextBytes(bytes); \/\/ \u751f\u6210\u4e00\u4e2a\u968f\u673a\u5b57\u8282\u6570\u7ec4<\/p>\n
int secureIntRandom = secureRandom.nextInt(); \/\/ \u751f\u6210\u5b89\u5168\u968f\u673a\u6574\u6570<\/p>\n
long secureLongRandom = secureRandom.nextLong(); \/\/ \u751f\u6210\u5b89\u5168\u968f\u673a\u957f\u6574\u578b\u6570<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u4e94\u3001\u4f7f\u7528 SplittableRandom<\/code> \u7c7b<\/h2>\n<\/p>\n
Java 8\u5f15\u5165\u4e86SplittableRandom<\/code> \u7c7b\uff0c\u7528\u4e8e\u63d0\u4f9b\u66f4\u597d\u7684\u6027\u80fd\uff0c\u5c24\u5176\u662f\u5728\u6570\u636e\u91cf\u5de8\u5927\uff0c\u9700\u8981\u9891\u7e41\u5229\u7528\u968f\u673a\u6570\u65f6\u3002\u5b83\u8bbe\u8ba1\u7528\u6765\u652f\u6301\u5e76\u884c\u8ba1\u7b97\uff0c\u5e76\u4e14\u80fd\u591f\u5206\u5272\u5176\u72b6\u6001\u5230\u4e0d\u540c\u7684\u968f\u673a\u6570\u751f\u6210\u5668\u4e0a\uff0c\u6bcf\u4e2a\u751f\u6210\u5668\u53ef\u4ee5\u72ec\u7acb\u66f4\u65b0\u3002<\/p>\n<\/p>\n
\u521b\u5efa SplittableRandom<\/code> \u5b9e\u4f8b<\/h3>\n<\/p>\n
SplittableRandom splittableRandom = new SplittableRandom(); \/\/ \u521b\u5efaSplittableRandom\u5b9e\u4f8b<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u751f\u6210\u968f\u673a\u6570<\/h3>\n<\/p>\n
SplittableRandom<\/code> \u7c7b\u4e3a\u5404\u79cd\u7528\u4f8b\u63d0\u4f9b\u4e86\u5f3a\u5927\u7684API\uff1a<\/p>\n<\/p>\n
int spIntRandom = splittableRandom.nextInt(1, 100); \/\/ \u751f\u62101(\u5305\u542b)\u5230100(\u4e0d\u5305\u542b)\u4e4b\u95f4\u7684\u968f\u673a\u6574\u6570<\/p>\n
double spDoubleRandom = splittableRandom.nextDouble(); \/\/ \u751f\u62100.0\u52301.0\u4e4b\u95f4\u7684\u968f\u673a\u53cc\u7cbe\u5ea6\u6570<\/p>\n
long spLongRandom = splittableRandom.nextLong(); \/\/ \u751f\u6210\u968f\u673a\u957f\u6574\u578b\u6570<\/p>\n
<\/code><\/pre>\n<\/p>\n
\u603b\u800c\u8a00\u4e4b\uff0cJava\u4e2d\u83b7\u53d6\u968f\u673a\u6570\u7684\u65b9\u6cd5\u65e2\u591a\u6837\u53c8\u5f3a\u5927\uff0c\u9002\u7528\u4e0d\u540c\u7684\u9700\u6c42\u548c\u5e94\u7528\u573a\u666f\u3002\u5f00\u53d1\u8005\u53ef\u4ee5\u6839\u636e\u7a0b\u5e8f\u7684\u5177\u4f53\u8981\u6c42\u9009\u62e9\u6700\u5408\u9002\u7684\u65b9\u5f0f\u4ee5\u786e\u4fdd\u6548\u7387\u548c\u5b89\u5168\u6027\u3002<\/p>\n<\/p>\n
\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n
1.\u5982\u4f55\u5728Java\u4e2d\u83b7\u53d6\u4e00\u4e2a\u968f\u673a\u6574\u6570\uff1f<\/strong>
\nJava\u4e2d\u83b7\u53d6\u4e00\u4e2a\u968f\u673a\u6574\u6570\u7684\u65b9\u6cd5\u6709\u5f88\u591a\u79cd\uff0c\u5176\u4e2d\u4e00\u79cd\u662f\u4f7f\u7528Java\u7684Random\u7c7b\u3002\u60a8\u53ef\u4ee5\u901a\u8fc7\u521b\u5efa\u4e00\u4e2aRandom\u5bf9\u8c61\uff0c\u7136\u540e\u8c03\u7528\u8be5\u5bf9\u8c61\u7684nextInt()\u65b9\u6cd5\u6765\u83b7\u53d6\u4e00\u4e2a\u968f\u673a\u6574\u6570\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u4ee3\u7801\u5c06\u751f\u6210\u4e00\u4e2a\u8303\u56f4\u57280\u523010\u4e4b\u95f4\u7684\u968f\u673a\u6574\u6570\uff1a<\/p>\n
Random rand = new Random();\nint randomNumber = rand.nextInt(11);\n<\/code><\/pre>\n
2.\u5982\u4f55\u5728Java\u4e2d\u83b7\u53d6\u4e00\u4e2a\u968f\u673a\u6d6e\u70b9\u6570\uff1f<\/strong>
\n\u8981\u5728Java\u4e2d\u83b7\u53d6\u968f\u673a\u6d6e\u70b9\u6570\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528Java\u7684Math\u7c7b\u7684random()\u65b9\u6cd5\u3002\u8be5\u65b9\u6cd5\u5c06\u8fd4\u56de\u4e00\u4e2a0\u52301\u4e4b\u95f4\u7684\u968f\u673a\u503c\u3002\u5982\u679c\u60a8\u9700\u8981\u751f\u6210\u4e00\u4e2a\u7279\u5b9a\u8303\u56f4\u5185\u7684\u968f\u673a\u6d6e\u70b9\u6570\uff0c\u60a8\u53ef\u4ee5\u5c06random()\u65b9\u6cd5\u8fd4\u56de\u7684\u503c\u4e0e\u8303\u56f4\u7684\u5dee\u503c\u76f8\u4e58\uff0c\u5e76\u5c06\u7ed3\u679c\u4e0e\u8303\u56f4\u7684\u8d77\u59cb\u503c\u76f8\u52a0\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0b\u4ee3\u7801\u5c06\u751f\u6210\u4e00\u4e2a\u8303\u56f4\u57280\u52301\u4e4b\u95f4\u7684\u968f\u673a\u6d6e\u70b9\u6570\uff1a<\/p>\n
double randomNumber = Math.random();\n<\/code><\/pre>\n
3.\u5982\u4f55\u5728Java\u4e2d\u83b7\u53d6\u4e00\u4e2a\u968f\u673a\u5b57\u7b26\u4e32\uff1f<\/strong>
\n\u8981\u5728Java\u4e2d\u83b7\u53d6\u4e00\u4e2a\u968f\u673a\u5b57\u7b26\u4e32\uff0c\u60a8\u53ef\u4ee5\u4f7f\u7528Java\u7684Random\u7c7b\u548cString\u7c7b\u7684charAt()\u65b9\u6cd5\u3002\u9996\u5148\uff0c\u60a8\u9700\u8981\u521b\u5efa\u4e00\u4e2a\u5305\u542b\u6240\u6709\u53ef\u80fd\u5b57\u7b26\u7684\u5b57\u7b26\u4e32\uff0c\u7136\u540e\u5229\u7528Random\u7c7b\u751f\u6210\u4e00\u4e2a\u968f\u673a\u6574\u6570\u4f5c\u4e3a\u7d22\u5f15\uff0c\u6700\u540e\u4f7f\u7528charAt()\u65b9\u6cd5\u83b7\u53d6\u8be5\u7d22\u5f15\u5904\u7684\u5b57\u7b26\u3002\u4ee5\u4e0b\u793a\u4f8b\u6f14\u793a\u4e86\u5982\u4f55\u83b7\u53d6\u4e00\u4e2a\u5305\u542b\u5927\u5199\u5b57\u6bcd\u548c\u6570\u5b57\u7684\u968f\u673a\u5b57\u7b26\u4e32\uff1a<\/p>\n
String characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";\nRandom rand = new Random();\nStringBuilder sb = new StringBuilder();\nint length = 8; \/\/ \u968f\u673a\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\nfor (int i = 0; i < length; i++) {\n    int randomIndex = rand.nextInt(characters.length());\n    char randomChar = characters.charAt(randomIndex);\n    sb.append(randomChar);\n}\nString randomString = sb.toString();\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"Java\u83b7\u53d6\u968f\u673a\u6570\u7684\u65b9\u6cd5\u4e3b\u8981\u5305\u62ec\uff1a Math.random()\u3001Random \u7c7b\u3001ThreadLocalRan […]","protected":false},"author":3,"featured_media":314405,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/314401"}],"collection":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/comments?post=314401"}],"version-history":[{"count":0,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/posts\/314401\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media\/314405"}],"wp:attachment":[{"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/media?parent=314401"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/categories?post=314401"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/docs.pingcode.com\/wp-json\/wp\/v2\/tags?post=314401"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}