{"id":1446,"date":"2024-04-14T11:32:52","date_gmt":"2024-04-14T03:32:52","guid":{"rendered":"http:\/\/zyg.luchers.cn\/?p=1446"},"modified":"2024-04-14T11:32:52","modified_gmt":"2024-04-14T03:32:52","slug":"%e5%b8%b8%e7%94%a8%e7%b1%bb%e3%80%90%e5%8c%85%e8%a3%85%e7%b1%bb%e3%80%81string-stringbuffer%e7%b1%bb%e3%80%81math%e7%b1%bb%e3%80%81arrays%e7%b1%bb%e3%80%81system%e7%b1%bb%e3%80%81biginteger%e5%92%8cbi","status":"publish","type":"post","link":"http:\/\/zyg.luchers.cn\/index.php\/2024\/04\/14\/%e5%b8%b8%e7%94%a8%e7%b1%bb%e3%80%90%e5%8c%85%e8%a3%85%e7%b1%bb%e3%80%81string-stringbuffer%e7%b1%bb%e3%80%81math%e7%b1%bb%e3%80%81arrays%e7%b1%bb%e3%80%81system%e7%b1%bb%e3%80%81biginteger%e5%92%8cbi\/","title":{"rendered":"\u5e38\u7528\u7c7b\u3010\u5305\u88c5\u7c7b\u3001String\/StringBuffer\u7c7b\u3001Math\u7c7b\u3001Arrays\u7c7b\u3001System\u7c7b\u3001BigInteger\u548cBigDecimal\u7c7b\u3001\u65e5\u671f\u7c7b\u3011"},"content":{"rendered":"

\u7b2c\u5341\u4e09\u7ae0\u3001\u5e38\u7528\u7c7b<\/h1>\n

\u5305\u88c5\u7c7b<\/h3>\n

\u5305\u88c5\u7c7b\u7684\u5206\u7c7b<\/h4>\n

1\u3001\u9488\u5bf9\u516b\u79cd\u57fa\u672c\u6570\u636e\u7c7b\u578b\u76f8\u5e94\u7684\u5f15\u7528\u7c7b\u578b\u2014\u5305\u88c5\u7c7b<\/p>\n

2\u3001\u6709\u4e86\u7c7b\u7684\u7279\u70b9\uff0c\u53ef\u4ee5\u8c03\u7528\u7c7b\u4e2d\u7684\u65b9\u6cd5\u3002<\/p>\n

3\u3001\u7c7b\u578b<\/p>\n

\"\"<\/div>
\n4\u3001\u516b\u4e2a\u5305\u88c5\u7c7b\u7684\u5173\u7cfb<\/p>\n

\uff081\uff09\u9ec4\u8272\u7684\u662f\u540c\u4e00\u4e2a\u7236\u7c7b<\/p>\n

\"\"<\/div>
\n\uff082\uff09char\u2014\u2014\u300bCharacter<\/p>\n

\"\"<\/div><\/p>\n

\uff083\uff09boolean\u2014\u2014\u300bBoolean<\/p>\n

\"\"<\/div><\/p>\n

\u5305\u88c5\u7c7b\u548c\u57fa\u672c\u6570\u636e\u7c7b\u578b\u7684\u8f6c\u6362<\/h4>\n

1\u3001jkd5\u4e4b\u524d\u662f\u624b\u52a8\u7684\u62c6\u7bb1\u548c\u88c5\u7bb1\uff0c<\/p>\n

\uff081\uff09\u88c5\u7bb1\uff1a\u57fa\u672c\u7c7b\u578b\u2014\u300b\u5305\u88c5\u7c7b\u578b<\/p>\n

\uff082\uff09\u62c6\u7bb1\uff1a\u53cd\u4e4b<\/p>\n

2\u3001jdk5\u548c5\u4ee5\u540e\u90fd\u662f\u81ea\u52a8\u62c6\u7bb1\u548c\u88c5\u7bb1<\/p>\n

3\u3001\u81ea\u52a8\u88c5\u7bb1\u5e95\u5c42\u662f\u8c03\u7528v alueOf\u65b9\u6cd5<\/p>\n

\uff081\uff09eg\uff1aInteger.valueOf()<\/p>\n

\uff082\uff09eg\uff1aint n2 =200\uff1b<\/p>\n

\u200b Integer integer = n2; \/\/\u81ea\u52a8\u88c5\u7bb1\u5e95\u5c42\u4ecd\u7136\u4f7f\u7528Inte.valueOf(n2);<\/p>\n

4\u3001\u81ea\u52a8\u62c6\u7bb1<\/p>\n

\uff081\uff09eg\uff1aint n3 = integer ; \/\/\u5e95\u5c42\u662fintValue()\u65b9\u6cd5<\/p>\n

\u5305\u88c5\u7c7b\u578b\u548cString\u7c7b\u578b\u7684\u76f8\u4e92\u8f6c\u6362<\/h4>\n

\u5305\u88c5\u7c7b\u2014\u2014\u300bString\u7c7b<\/h4>\n

\u65b9\u5f0f\u4e00\u3001\u76f4\u63a5\u5b57\u7b26\u4e32\u62fc\u63a5<\/h5>\n

eg\uff1aInteger i = 100\uff1b<\/p>\n

\u200b String str1 = i+ "";<\/p>\n

\u65b9\u5f0f\u4e8c\u3001toString()\u65b9\u6cd5<\/h5>\n

eg\uff1aString str2 = i.toString();<\/p>\n

\u65b9\u5f0f\u4e09\u3001valueOf();<\/h5>\n

eg\uff1aString str3 = String.valueOf();<\/p>\n

String\u7c7b\u2014\u2014\u300b\u5305\u88c5\u7c7b<\/h4>\n

\u65b9\u5f0f\u4e00\u3001parseInt()\u65b9\u6cd5<\/h5>\n

eg\uff1aInteger i2 = Integer.parseInt(str4) \/\/\u81ea\u52a8\u88c5\u7bb1<\/p>\n

\u65b9\u5f0f\u4e8c\u3001\u6784\u9020\u5668<\/h5>\n

eg\uff1aInteg i3 = new Integer(str4);<\/p>\n

String\u7c7b<\/h3>\n

String\u7c7b\u7684\u7406\u89e3<\/h4>\n

1\u3001String\u5bf9\u8c61\u7528\u4e8e\u4fdd\u5b58\u5b57\u7b26\u4e32\uff0c\u4e00\u7ec4\u5b57\u7b26\u5e8f\u5217<\/p>\n

2\u3001\u5b57\u7b26\u4e32\u5e38\u91cf\u5bf9\u8c61\u662f\u7528\u53cc\u5f15\u53f7\u62ec\u8d77\u7684\u5b57\u7b26\u5e8f\u5217\u3002\u4f8b\u5982\uff1a\u201c\u4f60\u597d\u201d\u3001\u201c12.97\u201c\u7b49<\/p>\n

3\u3001\u4f7f\u7528\u7684\u662fUnicode\u5b57\u7b26\u7f16\u7801\uff0c\u4e00\u4e2a\u5b57\u7b26\u4e24\u4e2a\u5b57\u8282<\/p>\n

4\u3001\u5e38\u7528\u6784\u9020\u5668(\u6709\u5f88\u591a\u4e2a)<\/p>\n

\uff081\uff09String s1 = new String\uff08\uff09\uff1b<\/p>\n

\uff082\uff09String s2= new String\uff08String orginal\uff09\uff1b<\/p>\n

\uff083\uff09String s3= new String\uff08char[] a\uff09\uff1b<\/p>\n

\uff084\uff09String s4 = new String\uff08char[] a ,int startIndex,int count\uff09\uff1b<\/p>\n

5\u3001String\u7c7b\u5b9e\u73b0\u4e86\u63a5\u53e3\uff1aSerializable\uff08String \u53ef\u4e32\u884c\u5316\uff1a\u53ef\u4ee5\u7f51\u7edc\u7f16\u7a0b\uff09<\/p>\n

6\u3001String\u7c7b\u5b9e\u73b0\u4e86\u63a5\u53e3\uff1aComparable\uff08String \u5bf9\u8c61\u53ef\u4ee5\u6bd4\u8f83\u5927\u5c0f\uff09<\/p>\n

7\u3001String \u662ffinal\u7c7b\uff0c\u4e0d\u80fd\u88ab\u5176\u4ed6\u7c7b\u7ee7\u627f<\/p>\n

8\u3001String\u6709\u5c5e\u6027 \uff1a private final char value[];\u7528\u4e8e\u5b58\u653e\u5b57\u7b26\u4e32\u5185\u5bb9<\/p>\n

9\u3001\u4e00\u5b9a\u6ce8\u610f\uff1avalue\u662f\u4e00\u4e2afinal\u7c7b\u578b<\/strong>\uff0c\u4e0d\u53ef\u4fee\u6539\uff08value\u5730\u5740\u4e0d\u80fd\u4fee\u6539\uff0c\u4e0d\u80fd\u6307\u5411\u5176\u4ed6\u5730\u5740\u7a7a\u95f4\uff09\u4f46\u662f\u5355\u4e2a\u5b57\u7b26\u53ef\u4ee5\u4fee\u6539 <\/p>\n

String\u521b\u5efa\u5bf9\u8c61\u7684\u4e24\u79cd\u65b9\u5f0f<\/h4>\n

1\u3001\u65b9\u5f0f\u4e00\uff1a\u76f4\u63a5\u8c03\u7528<\/p>\n

\uff081\uff09eg\uff1a String s = \u201chspedu\u201d;<\/p>\n

2\u3001\u65b9\u5f0f\u4e8c\uff1a\u8c03\u7528\u6784\u9020\u5668 String s = new String\uff08\u201chspedu\u201d\uff09;<\/p>\n

\u4e24\u79cd\u521b\u5efaString\u5bf9\u8c61\u7684\u533a\u522b<\/h5>\n

1\u3001\u65b9\u5f0f\u4e00\uff1a\u5148\u4ece\u5e38\u91cf\u6c60\u67e5\u770b\u662f\u5426\u6709\u201chsp\u201d\u6570\u636e\u7a7a\u95f4\uff0c\u5982\u679c\u6709\uff0c\u76f4\u63a5\u6307\u5411\uff1b\u5982\u679c\u6ca1\u6709\uff0c\u91cd\u65b0\u521b\u5efa\uff0c\u7136\u540e\u6307\u5411\uff0cs\u6700\u7ec8\u6307\u5411\u5e38\u91cf\u6c60\u7684\u7a7a\u95f4\u5730\u5740<\/p>\n

2\u3001\u65b9\u6cd5\u4e8c\uff1a\u5148\u5728\u5806\u4e2d\u521b\u5efa\u7a7a\u95f4\uff0c\u91cc\u9762\u7ef4\u62a4\u4e86value\u5c5e\u6027\uff0c\u6307\u5411\u5e38\u91cf\u6c60\u7684hsp\u7a7a\u95f4\u3002\u5982\u679c\u5e38\u91cf\u6c60\u6ca1\u6709\u201chsp\u201d\uff0c\u91cd\u65b0\u521b\u5efa\uff0c\u5982\u679c\u6709\uff0c\u76f4\u63a5\u6307\u5411\uff0c\u6700\u7ec8\u6307\u5411\u5806\u4e2d\u7684\u7a7a\u95f4\u5206\u5e03\u3002<\/p>\n

3\u3001\u5185\u5b58\u5206\u5e03\u56fe<\/p>\n

\"\"<\/div>
\n4\u8865\u5145\uff1aIntern\uff08\uff09\u65b9\u6cd5<\/p>\n

\uff081\uff09\u5f53\u8c03\u7528intern\u65b9\u6cd5\u65f6\uff0c\u5982\u679c\u5e38\u91cf\u6c60\u5df2\u7ecf\u5305\u542b\u4e86\u4e00\u4e2a\u7b49\u4e8e\u6b64String\u5bf9\u8c61\u7684\u5b57\u7b26\u4e32\uff08\u7528equals(Object)\u65b9\u6cd5\u786e\u5b9a\uff09\uff0c\u5219\u8fd4\u56de\u5e38\u91cf\u6c60\u4e2d\u7684\u5b57\u7b26\u4e32\u3002\u5426\u5219\uff0c\u5c06\u6b21String\u5bf9\u8c61\u6027\u6dfb\u52a0\u5230\u6c60\u4e2d\uff0c\u5e76\u8fd4\u56de\u6b21Sring\u5bf9\u7684\u5f15\u7528<\/p>\n

\uff082\uff09\u7406\u89e3\uff1a\u6700\u7ec8\u8fd4\u56de\u7684\u662f\u5e38\u91cf\u6c60\u7684\u5730\u5740<\/strong>\uff08\u5bf9\u8c61\uff09<\/p>\n

\u5b57\u7b26\u4e32\u7684\u7279\u6027<\/h4>\n

1\u3001String\u662f\u4e00\u4e2afinal\u7c7b\uff0c\u4ee3\u8868\u4e0d\u53ef\u53d8\u7684\u5b57\u7b26\u5e8f\u5217<\/p>\n

2\u3001\u5b57\u7b26\u4e32\u662f\u4e0d\u53ef\u53d8\u7684\u3002\u4e00\u4e2a\u5b57\u7b26\u4e32\u5bf9\u8c61\u4e00\u65e6\u88ab\u5206\u914d\uff0c\u5176\u5185\u5bb9\u662f\u4e0d\u53ef\u53d8\u7684\u3002<\/p>\n

\uff081\uff09\u5c0f\u7ed3\uff1a\u5e95\u5c42\u662f<\/p>\n

\u200b \u2460StringBuilder sb = new StringBuilder\uff08\uff09;<\/p>\n

\u200b sb.append(a)\uff1b<\/p>\n

\u200b \u2461sb.append(b); \/\/\u662f\u5728\u5806\u4e2d\uff0c\u5e76\u4e14append\u662f\u5728\u539f\u6765\u5b57\u7b26\u51fa\u7684\u57fa\u7840\u4e0a\u8ffd\u52a0\u7684<\/p>\n

\u200b \u2462String c1 =\u201cab",+"cd" \/\/\u5e38\u91cf\u76f8\u52a0\uff0c\u770b\u7684\u662f\u6c60<\/strong><\/p>\n

\u200b \u2463String c1 = a+b; \/\/\u53d8\u91cf\u76f8\u52a0\uff0c\u662f\u5728\u5806\u4e2d<\/strong><\/p>\n

String\u5e38\u7528\u65b9\u6cd5<\/h4>\n

\u8bf4\u660e\uff1aString\u662f\u4fdd\u5b58\u5b57\u7b26\u4e32\u5e38\u91cf\u7684\uff0c\u6bcf\u6b21\u66f4\u65b0\u90fd\u8981\u91cd\u65b0\u5f00\u8f9f\u7a7a\u95f4\uff0c\u6548\u7387\u4f4e\uff0c\u6240\u4ee5java\u8bbe\u8ba1\u8005\u63d0\u4f9bStringBuilder\u548cStringBuffer\u6765\u589e\u5f3aString\u7684\u529f\u80fd<\/p>\n

1\u3001equals\uff1a\u533a\u5206\u5927\u5c0f\u6bd4\u8f83\u5185\u5bb9\u662f\u5426\u76f8\u540c<\/p>\n

2\u3001equalsIgnoreCase\uff1a\u5ffd\u7565\u5927\u5c0f\u5199\u6bd4\u8f83 <\/p>\n

3\u3001length\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u957f\u5ea6<\/p>\n

4\u3001 indexOf\uff1a\u83b7\u53d6\u5b57\u7b26\u5728\u5b57\u7b26\u4e32\u5bf9\u8c61\u4e2d\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u7d22\u5f15\uff0c\u7d22\u5f15\u4ece0\u5f00\u59cb\uff0c\u5982\u679c\u627e\u4e0d\u5230\u8fd4\u56de-1<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b String s1 =wesaQwste;<\/p>\n

\u200b int index = s1.indexOf('Q'); \/\/\u5b57\u7b26\u4e32\u4e5f\u884c <\/p>\n

5\u3001lastIndexOf\uff1a\u83b7\u53d6\u5b57\u7b26\u5728\u5b57\u7b26\u4e32\u5bf9\u8c61\u4e2d\u6700\u540e\u4e00\u6b21\u51fa\u73b0\u7684\u7d22\u5f15\uff0c\u7d22\u5f15\u4ece0\u5f00\u59cb\uff0c\u5982\u679c\u627e\u4e0d\u5230\u8fd4\u56de-1<\/p>\n

6\u3001subString\uff1a\u622a\u53d6\u6307\u5b9a\u8303\u56f4\u7684\u5b50\u4e32\u3002<\/p>\n

\uff081\uff09eg<\/p>\n

String name = "abcdefghijklmn"; \/\/\u89d2\u68070\u5f00\u59cb<\/strong><\/p>\n

sout(name.substring(x,y)) \/\/\u622a\u53d6x--y\u8303\u56f4\u5185\u7684\u4fdd\u7559\u3002<\/p>\n

sout(name.substring(x)) \/\/\u622a\u53d6x\u4ee5\u540e\u7684\u6240\u6709\u5b57\u7b26\u4fdd\u7559<\/p>\n

7\u3001toUpperCase\uff1a\u8f6c\u6362\u4e3a\u5927\u5199<\/p>\n

8\u3001toLowerCase\uff1a\u8f6c\u6362\u4e3a\u5c0f\u5199<\/p>\n

9\u3001concat\uff1a\u5b57\u7b26\u4e32\u62fc\u63a5<\/p>\n

\uff081\uff09eg<\/p>\n

String s1 = "\u725b"<\/p>\n

s1 = s1.concat("\u554a").concat("\u795e\u4ed9"); \/\/\u7c7b\u4f3c+<\/p>\n

10\u3001replace\uff1a\u66ff\u6362\u5b57\u7b26\u4e32\u4e2d\u7684\u5b57\u7b26<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

s1 = s1.replace("xxx","yyy"); \/\/\u5728s1\u4e2d\u628a\u6240\u6709xxx\u5b57\u7b26\uff0c\u66ff\u6362\u6210yyy<\/p>\n

\uff082\uff09\u6ce8\u610f\uff1a\u5982\u679c\u4e0d\u8d4b\u503c\uff0c\u5219\u6ca1\u6709\u5bf9s1\u6709\u5f71\u54cd\uff08\u521b\u5efa\u65b0\u5bf9\u8c61\uff09<\/p>\n

10\u3001split\uff1a\u5206\u9694\u5b57\u7b26\u4e32\uff0c\u5bf9\u4e8e\u67d0\u4e9b\u5206\u9694\u5b57\u7b26\uff0c\u6211\u4eec\u9700\u8981\u8f6c\u4e49\uff0c\u6bd4\u5982| \\ \uff08\u5e38\u7528\u4e8e\uff0c\u5207\u5272\u57df\u540d\uff09<\/p>\n

\uff081\uff09eg<\/p>\n

String poem = \u201cxxxxx\uff0cyyyyy\uff0czzzzz\u201d;<\/p>\n

String [] split = poem.split(",");<\/p>\n

for()\/\/\u8f93\u51fasplit\u6570\u7ec4\u3002<\/p>\n

11\u3001toCharArray\uff1a\u5b57\u7b26\u4e32\u8f6c\u6362\u6210\u6570\u7ec4<\/p>\n

\uff081\uff09eg<\/p>\n

char[] chs = s.toCharArray();<\/p>\n

12\u3001compareTo\uff1a\u6bd4\u8f83\u4e24\u4e2a\u5b57\u7b26\u4e32\u7684\u5927\u5c0f\uff0c\u5982\u679c\u524d\u8005\u5927\uff0c\u5219\u8fd4\u56de\u6b63\u6570\uff0c\u540e\u8005\u5927\uff0c\u5219\u8fd4\u56de\u8d1f\u6570\uff0c\u5982\u679c\u76f8\u7b49\uff0c\u8fd4\u56de0\u3002<\/p>\n

13\u3001forma\uff1a\u683c\u5f0f\u5316\u5b57\u7b26\uff08c\u8bed\u8a00\u7684print\u8bed\u6cd5\uff09<\/p>\n

\uff081\uff09%s\uff1a\u5b57\u7b26\u4e32<\/p>\n

\uff082\uff09%c\uff1a\u5b57\u7b26<\/p>\n

\uff083\uff09%d\uff1a\u6574\u578b<\/p>\n

\uff084\uff09%.2f\uff1a\u6d6e\u70b9\u578b<\/p>\n

\uff085\uff09\u7406\u89e3\uff1a\u8fd9\u4e9b\u662f\u5360\u4f4d\u7b26\u7531\u540e\u9762\u53d8\u91cf\u6765\u66ff\u6362<\/p>\n

StringBuffer\u7c7b<\/h3>\n

\u57fa\u672c\u4ecb\u7ecd<\/h4>\n

1\u3001\u4ee3\u8868\u53ef\u53d8\u7684\u5b57\u7b26\u5e8f\u5217\uff0c\u53ef\u4ee5\u5bf9\u5b57\u7b26\u4e32\u5185\u5bb9\u8fdb\u884c\u589e\u5220<\/p>\n

2\u3001\u5f88\u591a\u5730\u65b9\u4e8eString\u76f8\u540c\uff0c\u4f46StringBuffer\u662f\u53ef\u53d8\u957f\u5ea6\u7684<\/p>\n

3\u3001StringBuffer\u662f\u4e00\u4e2a\u5bb9\u5668<\/p>\n

4\u3001\u7ed3\u6784\u56fe<\/p>\n

\"\"<\/div><\/p>\n

String VS StringBuffer<\/h4>\n

1\u3001String\u4fdd\u5b58\u7684\u662f\u5b57\u7b26\u4e32\u5e38\u91cf\uff0c\u91cc\u9762\u503c\u4e0d\u80fd\u6539\uff0c\u6bcf\u6b21String\u7c7b\u7684\u66f4\u65b0\u5b9e\u9645\u4e0a\u5c31\u662f\u66f4\u6539\u5730\u5740\uff0c\u6548\u7387\u4f4e\u4e0b \/\/private final char value[]<\/p>\n

2\u3001StringBuffer\u4fdd\u5b58\u7684\u662f\u5b57\u7b26\u4e32\u53d8\u91cf\uff0c\u91cc\u9762\u7684\u503c\u53ef\u4ee5\u66f4\u6539\uff0c\u6bcf\u6b21StringBuffer\u7684\u66f4\u65b0\u5b9e\u9645\u4e0a\u53ef\u4ee5\u66f4\u65b0\u5185\u5bb9\uff0c\u4e0d\u7528\u6bcf\u6b21\u66f4\u65b0\u5730\u5740\uff0c\u6548\u7387\u9ad8 \/\/cahr [] value;<\/p>\n

StringBuffer\u6784\u9020\u65b9\u6cd5<\/h4>\n

\"\"<\/div><\/p>\n

String \u548c StringBuffer\u76f8\u4e92\u8f6c\u6362<\/h4>\n

String\u2014\u2014\u300bStringBuffer<\/h5>\n

1\u3001\u4f7f\u7528\u6784\u9020\u5668<\/p>\n

\uff081\uff09\u6ce8\u610f\uff1a\u8fd4\u56de\u7684\u624d\u662fStringBuffer\u5bf9\u8c61\uff0c\u5bf9str\u672c\u8eab\u6ca1\u6709\u5f71\u54cd<\/p>\n

\uff082\uff09eg\uff1a<\/p>\n

\u200b \u2460String str = \u201chello tom\u201d;<\/p>\n

\u200b \u2461StringBuffer StringBuffer = new StringBuffer(str);<\/p>\n

\u200b 2\u3001\u4f7f\u7528append()\u65b9\u6cd5<\/p>\n

\uff081\uff09eg\uff1astringBuffer1 = stringBuffer1.append(str);<\/p>\n

StringBuffer \u2014\u2014\u300bString<\/h5>\n

1\u3001toString\u65b9\u6cd5<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b \u2460StringBuffer stringBuffer3 = new StringBuffer("\u554a\u6d9b\u597d\u5e05");<\/p>\n

\u200b \u2461String s = stringBuffer3.toString();<\/p>\n

2\u3001\u4f7f\u7528\u6784\u9020\u5668<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b \u2460String s1 = new String(stringBuffer3);<\/p>\n

String Buffer\u5e38\u7528\u65b9\u6cd5<\/h4>\n

1\u3001\u589e\u52a0\uff1aappend()\u65b9\u6cd5<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b \u2460StringBuffer s = new StringBuffer("\u554a\u6d9b\u597d\u5e05");<\/p>\n

\u200b \u2461s.append("\u5927\u50bb\u74dc") \/\/\u5728\u540e\u9762\u8ffd\u52a0<\/p>\n

2\u3001\u5220\u9664\uff1adelet()\u65b9\u6cd5<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b \u2460s.delete(xx,yy) \/\/\u5220\u9664xx\u5230yy\u7684\u503c[xx-yy).\u524d\u95ed\u540e\u5f00<\/p>\n

3\u3001\u66ff\u6362\uff1areplace() <\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b \u2460s.replace(xx,yy,mesg)\/\/\u66ff\u6362xx\u5230yy\u7684\u503c\uff0cmesg\u4e3a\u60f3\u8981\u66ff\u6362\u7684\u4fe1\u606f<\/p>\n

4\u3001\u67e5\u627e\u6307\u5b9a\u5b50\u4e32\u5728\u5b57\u7b26\u4e32\u7b2c\u4e00\u6b21\u51fa\u73b0\u7684\u7d22\u5f15\uff0c\u5982\u679c\u627e\u4e0d\u5230\u8fd4\u56de-1<\/p>\n

\uff081\uff09indexOf()\u65b9\u6cd5<\/p>\n

\uff082\uff09eg\uff1a<\/p>\n

\u200b \u2460int indexOf = s.indexOf("\u6d9b") \/\/1<\/p>\n

5\u3001\u63d2\u5165\u5b57\u7b26\u4e32\uff1ainsert()\u65b9\u6cd5<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b \u2460s.insert(xx,"mesg") \/\/\u5728\u7d22\u5f15\u4f4d\u7f6e\u4e3axx\u7684\u4f4d\u7f6e\u63d2\u5165\u201cmesg\u201d\uff0c\u539f\u6709\u4f4d\u7f6e\u81ea\u52a8\u540e\u79fb<\/p>\n

StringBuilder\u7c7b<\/h4>\n

\u57fa\u672c\u4ecb\u7ecd<\/h5>\n

1\u3001\u4e00\u4e2a\u53ef\u53d8\u7684\u5b57\u7b26\u5e8f\u5217\uff0c\u6b64\u7c7b\u63d0\u4f9b\u4e00\u4e2a\u4e0eStringBuffer\u517c\u5bb9\u7684API\uff0c\u4f46\u4e0d\u4fdd\u8bc1\u540c\u6b65\uff08StringBuilder\u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\uff09\u3002\u8be5\u7c7b\u88ab\u8bbe\u8ba1\u7528\u4f5cStringBuffer\u7684\u4e00\u4e2a\u7b80\u6613\u66ff\u6362\uff0c\u7528\u5728\u5b57\u7b26\u4e32\u7f13\u51b2\u533a\u88ab\u5355\u4e2a\u7ebf\u7a0b\u4f7f\u7528\u7684\u65f6\u5019<\/strong>\u3002\u5982\u679c\u53ef\u80fd\uff0c\u5efa\u8bae\u5148\u91c7\u7528\u8be5\u7c7b\uff0c\u5927\u591a\u6570\u60c5\u51b5\uff0cStringBuilder\u6bd4StringBuffer\u5feb<\/p>\n

2\u3001\u5728StringBuilder \u4e0a\u7684\u4e3b\u8981\u64cd\u4f5c\u662fappend\u548cinsert\u65b9\u6cd5\uff0c\u53ef\u91cd\u8f7d\u8fd9\u4e9b\u65b9\u6cd5\uff0c\u4ee5\u63a5\u53d7\u4efb\u610f\u7c7b\u578b\u7684\u6570\u636e\u3002<\/p>\n

3\u3001\u7ed3\u6784\u793a\u610f\u56fe<\/p>\n

\"\"<\/div>
\n4\u3001\u6ce8\u610f<\/p>\n

\uff081\uff09StringBUilder\u7ee7\u627fAbstractStringBuilder\u7c7b<\/p>\n

\uff082\uff09\u5b9e\u73b0\u4e86Serializable\uff0c\u8bf4\u660eStringBuilder\u5bf9\u8c61\u662f\u53ef\u4ee5\u4e32\u884c\u5316\uff08\u5bf9\u8c61\u662f\u53ef\u4ee5\u7f51\u7edc\u4f20\u8f93\uff0c\u53ef\u4ee5\u4fdd\u5b58\u5230\u6587\u4ef6\uff09<\/p>\n

\uff083\uff09StringBuilder\u662ffinal\u7c7b\uff0c\u4e0d\u80fd\u88ab\u7ee7\u627f<\/p>\n

\uff084\uff09StringBuilder\u5bf9\u8c61\u5b57\u7b26\u5e8f\u5217\u4ecd\u7136\u662f\u5b58\u653e\u5728\u5176\u7236\u7c7bAbstractStringBuilder\u7684char[] value;\u56e0\u6b64\uff0c\u5b57\u7b26\u5e8f\u5217\u662f\u5806\u4e2d<\/p>\n

\uff085\uff09StringBuilder\u7684\u65b9\u6cd5\uff0c\u6ca1\u6709\u505a\u4e92\u65a5\u5904\u7406\uff0c\u5373\u6ca1\u6709synchronized\u5173\u952e\u5b57\uff0c\u56e0\u6b64\u5728\u5355\u7ebf\u7a0b\u7684\u60c5\u51b5\u4e0b\u4f7f\u7528StringBuilder<\/p>\n

StringBuilder\u548cString\u548cStringBuffer\u6bd4\u8f83<\/h4>\n

1\u3001\u5185\u5bb9\u6bd4\u8f83\uff1a<\/p>\n

\uff081\uff09StringBuilder\u548cStringBuffer\u975e\u5e38\u7c7b\u4f3c\uff0c\u5747\u4ee3\u8868\u53ef\u53d8\u7684\u5b57\u7b26\u5e8f\u5217\uff0c\u800c\u4e14\u65b9\u6cd5\u4e5f\u4e00\u6837\u3002<\/p>\n

\uff082\uff09String\uff1a\u4e0d\u53ef\u53d8\u5b57\u7b26\u5e8f\u5217\uff0c\u6548\u7387\u4f4e\uff0c\u4f46\u662f\u590d\u7528\u7387\u9ad8<\/p>\n

\uff083\uff09StringBuffer\uff1a\u53ef\u53d8\u5b57\u7b26\u5e8f\u5217\uff0c\u6548\u7387\u9ad8\uff08\u589e\u5220\uff09\uff0c\u7ebf\u7a0b\u5b89\u5168<\/p>\n

\uff084\uff09StringBuilder\uff1a\u53ef\u53d8\u5b57\u7b26\u5e8f\u5217\uff0c\u6548\u7387\u6700\u9ad8\uff0c\u7ebf\u7a0b\u4e0d\u5b89\u5168<\/p>\n

\uff085\uff09String\u4f7f\u7528\u8bf4\u660e\uff1astring\u5b9e\u9645\u4e0a\u539f\u6765\u7684\u201ca\u201c\u5b57\u7b26\u4e32\u5bf9\u8c61\u4ee5\u53ca\u4e22\u5f03\u4e86\uff0c\u73b0\u5728\u6709\u4ea7\u751f\u4e86\u4e00\u4e2a\u5b57\u7b26\uff0c\u5982\u679c\u591a\u6b21\u6267\u884c\uff0c\u6548\u7387\u6781\u4f4e\u3002<\/p>\n

\u200b \u2460\u7ed3\u8bba\uff1a\u5982\u679c\u6211\u4eec\u5bf9String\u505a\u5927\u91cf\u4fee\u6539\uff0c\u4e0d\u8981\u4f7f\u7528String<\/p>\n

2\u3001\u4f7f\u7528\u539f\u5219\uff01<\/p>\n

\uff081\uff09\u5982\u679c\u5b57\u7b26\u4e32\u5b58\u5728\u5927\u91cf\u4fee\u6539\u64cd\u4f5c\uff0c\u4e00\u822c\u4f7f\u7528StringBuffer\u6216StringBuilder<\/p>\n

\uff082\uff09\u5982\u679c\u5b57\u7b26\u4e32\u5b58\u5728\u5927\u91cf\u4fee\u6539\u64cd\u4f5c\uff0c\u5e76\u5728\u5355\u7ebf\u7a0b\u7684\u60c5\u51b5\uff0c\u4f7f\u7528StringBuilder<\/p>\n

\uff083\uff09\u5982\u679c\u5b57\u7b26\u4e32\u5b58\u5728\u5927\u91cf\u4fee\u6539\u64cd\u4f5c\uff0c\u5e76\u5728\u591a\u7ebf\u7a0b\u7684\u60c5\u51b5\uff0c\u4f7f\u7528StringBuffer<\/p>\n

\uff084\uff09\u5982\u679c\u6211\u4eec\u5b57\u7b26\u4e32\u5f88\u5c11\u4fee\u6539\uff0c\u88ab\u591a\u4e2a\u5bf9\u8c61\u5f15\u7528\uff0c\u4f7f\u7528String\uff0c\u6bd4\u5982\u6570\u636e\u5e93\u4fe1\u606f\u914d\u7f6e\u7b49<\/p>\n

Math\u7c7b<\/h3>\n

\u5e38\u7528\u65b9\u6cd5<\/h4>\n

1\u3001Math.abs\uff1a\u7edd\u5bf9\u503c<\/p>\n

2\u3001Math.pow(x\uff0cy)\uff1ax\u7684y\u6b21\u65b9<\/p>\n

3\u3001Math.ceil():\u5411\u4e0a\u53d6\u6574\uff0c\u8fd4\u56de>=\u8be5\u53c2\u6570\u7684\u6700\u5c0f\u6574\u6570<\/p>\n

\uff081\uff09eg\uff1aMath.ceil(-3.0001) \/\/\u7ed3\u679c\u4e3a\uff1a-3<\/p>\n

4\u3001Math.floor()\uff1a\u5411\u4e0b\u53d6\u6574\uff0c\u8fd4\u56de<=\u8be5\u53c2\u6570\u7684\u6700\u5927\u6574\u6570<\/p>\n

5\u3001Math.round()\uff1a\u56db\u820d\u4e94\u5165\uff0cMath.floor(\u8be5\u53c2\u6570+0.5)<\/p>\n

6\u3001Math.sqrt()\uff1a\u5f00\u65b9\u3002<\/p>\n

7\u3001Math.random\uff1a\u6c42\u968f\u673a\u6570\uff0c\u8fd4\u56de\u7684\u662f0-1\u4e4b\u95f4\u7684\u968f\u673a\u5c0f\u6570\uff0c\u524d\u95ed\u540e\u5f00<\/p>\n

8\u3001Math.min()\uff1a\u8fd4\u56de\u6700\u5c0f\u503c<\/p>\n

9\u3001Math.max()\uff1a\u8fd4\u56de\u6700\u5927\u503c<\/p>\n

Arrays\u7c7b<\/h3>\n

\u5e38\u7528\u65b9\u6cd5<\/h4>\n

1\u3001toString()\uff1a\u8fd4\u56de\u6570\u7ec4\u7684\u5b57\u7b26\u4e32\u5f62\u5f0f<\/p>\n

(1)eg\uff1a<\/p>\n

\u200b Arrays.toString(arr)<\/p>\n

2\u3001sort()\uff1a\u5347\u5e8f\u6392\u5e8f<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b Arrays.sort(arr);<\/p>\n

\uff082\uff09\u56e0\u4e3a\u6570\u7ec4\u662f\u5f15\u7528\u7c7b\u578b\uff0c\u6240\u4ee5\u901a\u8fc7sort\u6392\u5e8f\u540e\uff0c\u4f1a\u76f4\u63a5\u5f71\u54cd\u5230\u5b9e\u53c2arr<\/p>\n

\uff083\uff09\u5b9a\u5236\u6392\u5e8f<\/p>\n

3\u3001binarySearch\uff1a\u4e8c\u5206\u6cd5\u641c\u7d22\u67e5\u627e\u3002<\/p>\n

\uff081\uff09\u6ce8\u610f\uff1a<\/p>\n

\u200b \u2460\u8981\u6c42\u5fc5\u987b\u6570\u7ec4\u662f\u6709\u5e8f\u7684\uff0c\u65e0\u987b\u5219\u65e0\u6cd5\u4f7f\u7528binarySeach<\/p>\n

\u200b \u2461\u5982\u679c\u6570\u7ec4\u4e2d\u4e0d\u5b58\u5728\u8be5\u5143\u7d20\uff0c\u5219\u8fd4\u56de-1<\/p>\n

\uff082\uff09\u7528\u6cd5\uff1aint index = Arrays.binarySeach(arr,0);<\/p>\n

\u200b Sout("index = " + index); <\/p>\n

\uff083\uff09\u5982\u679c\u627e\u4e0d\u5230\u8be5\u5143\u7d20\uff0c\u5219\u8fd4\u56dereturn -(low +1); \/\/low\u662f\u6210\u529f\u90a3\u4e2a<\/p>\n

4\u3001copyOf()\uff1a\u6570\u7ec4\u5143\u7d20\u7684\u590d\u5236<\/p>\n

\uff081\uff09Integer newArr = Arrays.copyOf(arr, arr.length);<\/p>\n

\uff082\uff09\u7406\u89e3\uff1a\u4ecearr\u6570\u7ec4\u4e2d\uff0c\u62f7\u8d1darr.length\u4e2a\u5143\u7d20\u5230newArr\u6570\u7ec4\u4e2d<\/p>\n

\uff083\uff09\u5982\u679c\u62f7\u8d1d\u957f\u5ea6>arr.length\u5c31\u5728\u65b0\u6570\u7ec4\u540e\u9762\uff0c\u589e\u52a0null<\/p>\n

\uff084\uff09\u5982\u679c\u62f7\u8d1d\u957f\u5ea6<0\u5c31\u629b\u51fa\u5f02\u5e38NegativeArraySizeException<\/p>\n

\uff085\uff09\u8be5\u65b9\u6cd5\u4f4e\u5c42\u4f7f\u7528\u7684\u662fSystem.arraycopy()<\/p>\n

5\u3001fill()\u65b9\u6cd5\uff1a\u6570\u7ec4\u5143\u7d20\u7684\u586b\u5145 <\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b \u2460\uff1aInteger[] num = new Integer[] {9,3,2};<\/p>\n

\u200b \u2461\uff1aArrays.fill(num,99);<\/p>\n

\u200b \u2462\uff1a\u7406\u89e3\uff1a\u4f7f\u752899\u53bb\u586b\u5145num\u6570\u7ec4\uff0c\u53ef\u4ee5\u7406\u89e3\u6210\u662f\u66ff\u6362\u539f\u7406\u7684\u5143\u7d20<\/p>\n

6\u3001equals\uff1a\u6bd4\u8f83\u4e24\u4e2a\u6570\u7ec4\u5143\u7d20\u5185\u5bb9\u662f\u5426\u5b8c\u5168\u4e00\u81f4<\/p>\n

\uff081\uff09eg\uff1a<\/p>\n

\u200b \u2460\uff1aboolean equals = Arrays.equals(arr,arr2);<\/p>\n

\u200b \/\/\u6bd4\u8f83arr\uff0carr2\u6570\u7ec4\u5143\u7d20\u662f\u5426\u5b8c\u5168\u4e00\u81f4<\/p>\n

7\u3001aList\u5c06\u4e00\u7ec4\u6570\u503c\uff0c\u8f6c\u6362\u6210list<\/p>\n

\uff081\uff09aList\u65b9\u6cd5\uff0c\u4f1a\u5c06\uff082,3,4,5,6,1\uff09\u6570\u636e\u8f6c\u6210\u4e00\u4e2aList\u96c6\u5408<\/p>\n

\uff082\uff09\u8fd4\u56de\u7684asList\u7f16\u8bd1\u7c7b\u578bList(\u63a5\u53e3)<\/p>\n

System\u7c7b<\/h3>\n

1\u3001exit\uff1a\u9000\u51fa\u5f53\u524d\u7a0b\u5e8f<\/p>\n

2\u3001arraycopy\uff1a\u8d4b\u503c\u6570\u7ec4\u5143\u7d20\uff0c\u6bd4\u8f83\u9002\u5408\u4f4e\u5c42\u8c03\u7528\uff0c\u4e00\u822c\u4f7f\u7528Arrays.copyOf\u5b8c\u6210\u590d\u5236\u6570\u7ec4<\/p>\n

\uff081\uff09eg\uff1aint [] src = {1,2,3};<\/p>\n

\u200b int [] dest = new int[3];<\/p>\n

\u200b System.out.println(src,0,dest,0,3);<\/p>\n

\uff082\uff09\u7406\u89e3\uff1a<\/p>\n

\u200b \u2460src\u8868\u793a\uff1a\u539f\u6765\u7684\u6570\u7ec4<\/p>\n

\u200b \u24610\u8868\u793a\uff1a\u4ece\u7d22\u5f15\u54ea\u4e2a\u4f4d\u7f6e\u5f00\u59cb\u62f7\u8d1d<\/p>\n

\u200b \u2462dest\uff1a\u76ee\u6807\u6570\u7ec4\uff0c\u628a\u539f\u6570\u7ec4\u62f7\u8d1d\u5230dest\u6570\u7ec4 <\/p>\n

\u200b \u24630\u8868\u793a\uff1a\u62f7\u8d1d\u5230\u76ee\u6807\u6570\u7ec4\u7684\u54ea\u4e2a\u7d22\u5f15\u4f4d\u7f6e<\/p>\n

\u200b \u24643\uff1a\u8868\u793a\u4ece\u539f\u6570\u7ec4\u62f7\u8d1d\u591a\u5c11\u4e2a\u5230\u539f\u6570\u7ec4<\/p>\n

3\u3001currentTimeMillens:\u8fd4\u56de\u5f53\u524d\u65f6\u95f4\u8ddd\u79bb1970-1-1\u7684\u6beb\u79d2\u6570<\/p>\n

4\u3001gc\uff1a\u8fd0\u884c\u5783\u573e\u56de\u6536\u673a\u5236System.gc();<\/p>\n

BigInteger\u548cBigDecimal\u7c7b<\/h3>\n

BigInteger\u548cBigDecimal\u4ecb\u7ecd<\/h4>\n

BigInteger<\/h5>\n

1\u3001\u5e94\u7528\u573a\u666f<\/p>\n

\uff081\uff09BigInteger\u9002\u5408\u4fdd\u5b58\u6bd4\u8f83\u5927\u7684\u6574\u578b<\/p>\n

\uff082\uff09BigDecimal\u9002\u5408\u4fdd\u5b58\u8fdb\u5ea6\u66f4\u9ad8\u7684\u6d6e\u70b9\u6570\uff08\u5c0f\u6570\uff09<\/p>\n

2\u3001BigInteger\u7406\u89e3<\/p>\n

\uff081\uff09\u4f4e\u5c42\u662f\u8f6c\u5316\u4e3a\u5b57\u7b26\u4e32<\/p>\n

\uff082\uff09\u56db\u5219\u8fd0\u7b97\u9700\u8981\u8c03\u7528\u65b9\u6cd5<\/p>\n

\u200b \u2460add\uff1a\u52a0<\/p>\n

\u200b \u2461subtract\uff1a\u51cf<\/p>\n

\u200b \u2462multiply\uff1a\u4e58<\/p>\n

\u200b \u2463divide\uff1a\u9664<\/p>\n

3\u3001eg\uff1a<\/p>\n

\uff081\uff09BigInteger bgI = new BigInteger\uff08\u201c999999999999999999999999999999999999999999999999\u201d\uff09;<\/p>\n

\uff082\uff09BigInteger add = bgI.add(new BigInteger("8888888"))\uff1b<\/p>\n

\uff083\uff09sout(add);<\/p>\n

BigDecimal<\/h5>\n

1\u3001\u7406\u89e3\uff1a\u548cBigInteger\u7c7b\u4f3c<\/p>\n

2\u3001\u4e0d\u540c<\/p>\n

\uff081\uff09\u5982\u679c\u5728\u8c03\u7528divide\u65b9\u6cd5\u65f6\uff0c\u6307\u5b9a\u7cbe\u5ea6\u5373\u53ef.BigDecimal.ROUND_CEILING<\/p>\n

\uff082\uff09\u5982\u679c\u6709\u65e0\u9650\u5faa\u73af\u5c0f\u6570\uff0c\u5c31\u4f1a\u4fdd\u7559\u5206\u5b50\u7684\u8fdb\u5ea6<\/p>\n

\uff083\uff09eg\uff1a<\/p>\n

\u200b \u2460BigInteger bgI = new BigInteger\uff08\u201c99999999999.9999999999999999999999999999999999999\u201d\uff09;<\/p>\n

\u200b \u2461sout.println(bigDecimal.divide(bigDecimal2,BigDecimal.ROUND_CEILING));<\/p>\n

\u65e5\u671f\u7c7b<\/h3>\n

\u7b2c\u4e00\u4ee3\u65e5\u671f\u7c7b<\/h4>\n

1\u3001Date\uff1a\u7cbe\u786e\u5230\u6beb\u79d2\uff0c\u4ee3\u8868\u7279\u5b9a\u7684\u77ac\u95f4<\/p>\n

\uff081\uff09\u65b0\u5efa\u5bf9\u8c61\uff0c\u5bf9\u8c61\u5c31\u4f1a\u8f93\u51fa\u4e00\u4e2a\u9ed8\u8ba4\u7684\u65e5\u671f\u683c\u5f0f\uff0c\u4e00\u822c\u4e3a\u56fd\u5916\u7684\u65b9\u5f0f\uff0c\u6240\u4ee5\u9700\u8981\u8fdb\u884c\u683c\u5f0f\u8f6c\u6362<\/p>\n

2\u3001SimpleDateFormat\uff1a\u683c\u5f0f\u548c\u89e3\u6790\u65e5\u671f\u7684\u7c7b<\/p>\n

\uff081\uff09\u53ef\u4ee5\u6307\u5b9a\u683c\u5f0f<\/p>\n

\uff082\uff09\u5728\u65b0\u5efaSimpleDateFormat\u5bf9\u8c61\u521b\u5efa\uff0c\u4f20\u5165\uff08\u201c\u65e5\u671f\u683c\u5f0f\u201d\uff09<\/p>\n

\uff083\uff09eg\uff1a<\/p>\n

\u200b SimpleDateFormat sp = new SimpleDateFormat("yyyyddmmhhmmss E")<\/p>\n

\u200b String format = sp.format(d1);<\/p>\n

3\u3001SimpleDateFormat\u683c\u5f0f\u548c\u89e3\u6790\u65e5\u671f\u7684\u5177\u4f53\u7c7b\u3002<\/p>\n

\uff081\uff09\u5b83\u5141\u8bb8\u8fdb\u884c\u683c\u5f0f\u5316\uff08\u65e5\u671f\u2014>\u6587\u672c\uff09<\/p>\n

\uff082\uff09\u5141\u8bb8\u89e3\u6790\uff1a\uff08\u6587\u672c\u2014>\u65e5\u671f\uff09\u548c\u89c4\u8303\u5316<\/p>\n

4\u3001\u901a\u8fc7\u6beb\u79d2\u6570\u8fdb\u884c\u65f6\u95f4\u7684\u8fd0\u7b97<\/p>\n

\uff081\uff09Date d2 = new Date(888888);<\/p>\n

5\u3001\u683c\u5f0f\u5316\u5b57\u7b26\u4e32\u8f6c\u6210Date<\/p>\n

\uff081\uff09\u65e5\u671f\u683c\u5f0f\u4e00\u5b9a\u8981\u6b63\u786e\uff08\u5339\u914d\u548c\u8bbe\u7f6e\u7684\u65e5\u671f\u4e00\u5b9a\u8981\u5339\u914d\uff09<\/p>\n

\uff082\uff09eg\uff1a<\/p>\n

    String a = "2022\u5e7412\u670819\u65e5\u300206:22:11 \u661f\u671f\u4e00";\n    Date parse = sdf.parse(a);\n    System.out.println(sdf.format(parse));<\/code><\/pre>\n
\u7b2c\u4e8c\u4ee3\u65e5\u671f\u7c7b<\/h4>\n
1\u3001\u662f\u4e00\u4e2a\u62bd\u8c61\u7c7b\u3001\u6784\u9020\u5668\u662fprotected\uff0c<\/p>\n
2\u3001\u53ef\u4ee5\u901a\u8fc7getINstance()\u6765\u83b7\u53d6\u5b9e\u4f8b<\/p>\n
3\u3001\u63d0\u4f9b\u5927\u91cf\u7684\u65b9\u6cd5\u548c\u5b57\u6bb5<\/p>\n
4\u3001\u65b9\u6cd5c.get(Calendar.MONTH)<\/p>\n
Calendar c =  Calendar.getInstance();\nSystem.out.println("c="+ c);\nSystem.out.println("\u5e74\uff1a"+c.get(Calendar.YEAR));\nSystem.out.println("\u6708\uff1a"+c.get(Calendar.MONTH)+1);\nSystem.out.println("\u65e5\uff1a"+c.get(Calendar.DAY_OF_MONTH));\nSystem.out.println("\u5c0f\u65f6\uff1a"+c.get(Calendar.HOUR));\nSystem.out.println("\u949f\uff1a"+c.get(Calendar.MINUTE));\nSystem.out.println("\u79d2\uff1a"+c.get(Calendar.SECOND));<\/code><\/pre>\n
5\u3001Calendar\u6ca1\u6709\u63d0\u4f9b\u4e13\u95e8\u7684\u683c\u5f0f\u5316\u65b9\u6cd5\uff0c\u6240\u4ee5\u9700\u8981\u7a0b\u5e8f\u5458\u81ea\u5df1\u6765\u7ec4\u5408\u663e\u793a<\/p>\n
6\u3001\u5982\u679c\u60f3\u663e\u793a24\u5c0f\u65f6<\/p>\n
\uff081\uff09\u628a\u5b57\u6bb5\u6539\u6210\uff1aHOUR_OF_DAY<\/p>\n
\u7b2c\u4e09\u4ee3\u65e5\u671f\u7c7b<\/h4>\n
1\u3001\u56e0\u4e3aCalendar\u4e5f\u5b58\u5728\u95ee\u9898<\/p>\n
\uff081\uff09\u53ef\u53d8\u6027\uff1a\u50cf\u65e5\u671f\u548c\u65f6\u95f4\u8fd9\u6837\u7684\u7c7b\u5e94\u8be5\u662f\u4e0d\u53ef\u53d8\u7684\u3002<\/p>\n
\uff082\uff09\u504f\u79fb\u6027\uff1aDate\u4e2d\u7684\u5e74\u4efd\u662f\u4ece1900\u5f00\u59cb\uff0c\u800c\u6708\u4efd\u90fd\u662f\u4ece0\u5f00\u59cb\uff08\u6240\u4ee5\u8981+1\uff09<\/p>\n
\uff083\uff09\u683c\u5f0f\u5316\uff1a\u683c\u5f0f\u5316\u53ea\u5bf9Date\u6709\u7528\uff0cCalendar\u5219\u4e0d\u884c\u3002<\/p>\n
\uff084\uff09\u6b64\u5916\uff0c\u5b83\u4eec\u4e5f\u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\uff1b\u4e0d\u80fd\u5904\u7406\u95f0\u79d2\u7b49\uff08\u6bcf\u9694\u4e24\u5929\uff0c\u591a\u51fa1s\uff09<\/p>\n
\u5e38\u7528\u65b9\u6cd5<\/h5>\n
1\u3001LocalDate\uff08\u65e5\u671f\/\u5e74\u6708\u65e5\uff09<\/p>\n
2\u3001LocalTime\uff08\u65f6\u95f4\/\u65f6\u5206\u79d2\uff09<\/p>\n
3\u3001LocalDateTime\uff08\u65e5\u671f\u65f6\u95f4\/\u5e74\u6708\u65e5\u65f6\u5206\u79d2\uff09<\/p>\n
\uff081\uff09\u4f7f\u7528now()\u8fd4\u56de\u8868\u793a\u5f53\u524d\u65e5\u671f\u65f6\u95f4\u7684\u5bf9\u8c61<\/p>\n
LocalDateTime ldt = LocalDateTime.now();
\nSystem.out.println(ldt);<\/p>\n
\uff082\uff093\u5305\u542b\u4e861\u548c2<\/p>\n
    LocalDateTime ldt = LocalDateTime.now();\n    System.out.println(ldt);\n    System.out.println("\u5e74"+ldt.getYear());\n    System.out.println("\u6708"+ldt.getMonth());\n    System.out.println("\u65e5"+ldt.getMonthValue());\n    System.out.println("\u65f6"+ldt.getHour());\n    System.out.println("\u5206"+ldt.getMinute());\n    System.out.println("\u79d2"+ldt.getSecond());\n\n    LocalDate now  =LocalDate.now();\/\/\u53ef\u4ee5\u83b7\u53d6\u5e74\u6708\u65e5\n    LocalTime now2 =LocalTime.now();\/\/\u83b7\u53d6\u5230\u65f6\u5206\u79d2\n    System.out.println(now);\n    System.out.println(now2);<\/code><\/pre>\n
4\u3001DateTimeFormat\u5bf9\u8c61\u6765\u8fdb\u884c\u683c\u5f0f\u5316        \/\/jdk1.8\u624d\u6709<\/p>\n
DateTimeFormatter dateTimeFormatter  = DateTimeFormatter.ofPattern("yyyy-MM-dd hh:mm:ss");
\nSystem.out.println(dateTimeFormatter);
\nString format = dateTimeFormatter.format(ldt);
\nSystem.out.println(format);<\/p>\n
5\u3001Instant\u65f6\u95f4\u6233<\/p>\n
\uff081\uff09\u7c7b\u4f3c\u4e8eDate<\/p>\n
\uff082\uff09\u63d0\u4f9b\u4e86\u4e00\u4e9b\u5217\u548cDate\u7684\u8f6c\u6362\u65b9\u5f0f<\/p>\n
\uff083\uff09Instant\u2014>Date\uff1aDate.from(instant);<\/p>\n
\uff084\uff09Date\u2014>Instant\uff1adate.toInstant();<\/p>\n
    \/\/\u9759\u6001 now() \u83b7\u53d6\u8868\u793a\u5f53\u524d\u65f6\u95f4\u6233\u7684\u5bf9\u8c61\n    Instant now = Instant.now();\n    System.out.println(now);\n    \/\/\u901a\u8fc7from\u53ef\u4ee5\u628aInstant\u8f6c\u6362\u6210Date\n    Date date = Date.from(now);\n    Instant instant = date.toInstant();<\/code><\/pre>\n
6\u3001\u63d0\u4f9bplus\u80afminus\u65b9\u6cd5\u53ef\u4ee5\u5bf9\u5f53\u524d\u65f6\u95f4\u8fdb\u884c\u52a0\u6216\u8005\u51cf<\/p>\n
\uff081\uff09plus();<\/p>\n
    \/\/\u6dfb\u52a0800\u5929\u540e\u8f93\u51fa\n    LocalDateTime localDateTime=ldt.plusDays(800);\n    System.out.println(localDateTime);<\/code><\/pre>\n
\uff082\uff09Minus();<\/p>\n
\/\/        \u57283456\u5206\u949f\u524d\u662f\u4ec0\u4e48\u65f6\u5019\uff0c \u628a\u5e74\u6708\u65e5\u65f6\u5206\u79d2\u6253\u5370
\nLocalDateTime localDateTime2 =ldt.minusMinutes(3456);
\nSystem.out.println(localDateTime2);<\/p>\n","protected":false},"excerpt":{"rendered":"
\u7b2c\u5341\u4e09\u7ae0\u3001\u5e38\u7528\u7c7b \u5305\u88c5\u7c7b \u5305\u88c5\u7c7b\u7684\u5206\u7c7b 1\u3001\u9488\u5bf9\u516b\u79cd\u57fa\u672c\u6570\u636e\u7c7b\u578b\u76f8\u5e94\u7684\u5f15\u7528\u7c7b\u578b\u2014\u5305\u88c5\u7c7b 2\u3001\u6709\u4e86\u7c7b\u7684\u7279\u70b9\uff0c\u53ef\u4ee5 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[20],"tags":[],"class_list":["post-1446","post","type-post","status-publish","format-standard","hentry","category-java"],"_links":{"self":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/1446","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/comments?post=1446"}],"version-history":[{"count":1,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/1446\/revisions"}],"predecessor-version":[{"id":5495,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/posts\/1446\/revisions\/5495"}],"wp:attachment":[{"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/media?parent=1446"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/categories?post=1446"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/zyg.luchers.cn\/index.php\/wp-json\/wp\/v2\/tags?post=1446"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}