compile 'com.google.guava:guava:30.0-jre'<\/code><\/pre>\n\u5f15\u5165Maven\u4f9d\u8d56<\/p>\n
<!-- https:\/\/mvnrepository.com\/artifact\/com.google.guava\/guava -->\n<dependency>\n <groupId>com.google.guava<\/groupId>\n <artifactId>guava<\/artifactId>\n <version>30.0-jre<\/version>\n<\/dependency><\/code><\/pre>\n\u96c6\u5408\u7684\u521b\u5efa<\/h3>\n\/\/ \u666e\u901aCollection\u7684\u521b\u5efa\nList<String> list = Lists.newArrayList();\nSet<String> set = Sets.newHashSet();\nMap<String, String> map = Maps.newHashMap();\n\n\/\/ \u4e0d\u53d8Collection\u7684\u521b\u5efa\nImmutableList<String> iList = ImmutableList.of("a", "b", "c");\nImmutableSet<String> iSet = ImmutableSet.of("e1", "e2");\nImmutableMap<String, String> iMap = ImmutableMap.of("k1", "v1", "k2", "v2");<\/code><\/pre>\n\u521b\u5efa\u4e0d\u53ef\u53d8\u96c6\u5408\uff0c\u5148\u7406\u89e3\u4ec0\u4e48\u662fimmutable(\u4e0d\u53ef\u53d8)\u5bf9\u8c61<\/p>\n
\n- \u5728\u591a\u7ebf\u7a0b\u64cd\u4f5c\u4e0b\uff0c\u662f\u7ebf\u7a0b\u5b89\u5168\u7684<\/li>\n
- \u6240\u6709\u4e0d\u53ef\u53d8\u96c6\u5408\u4f1a\u6bd4\u53ef\u53d8\u96c6\u5408\u66f4\u6709\u6548\u7684\u5229\u7528\u8d44\u6e90<\/li>\n
- \u4e2d\u9014\u4e0d\u53ef\u6539\u53d8<\/li>\n<\/ul>\n
ImmutableList<String> immutableList = ImmutableList.of("1","2","3","4");<\/code><\/pre>\n\u8fd9\u58f0\u660e\u4e86\u4e00\u4e2a\u4e0d\u53ef\u53d8\u7684List\u96c6\u5408\uff0cList\u4e2d\u6709\u6570\u636e1\uff0c2\uff0c3\uff0c4\u3002\u7c7b\u4e2d\u7684\u64cd\u4f5c\u96c6\u5408\u7684\u65b9\u6cd5\uff08\u8b6c\u5982add, set, sort, replace\u7b49\uff09\u90fd\u88ab\u58f0\u660e\u8fc7\u671f\uff0c\u5e76\u4e14\u629b\u51fa\u5f02\u5e38\u3002\u800c\u6ca1\u7528guava\u4e4b\u524d\u662f\u9700\u8981\u58f0\u660e\u5e76\u4e14\u52a0\u5404\u79cd\u5305\u88f9\u96c6\u5408\u624d\u80fd\u5b9e\u73b0\u8fd9\u4e2a\u529f\u80fd<\/p>\n
\/\/ add \u65b9\u6cd5\n@Deprecated @Override\npublic final void add(int index, E element) {\n throw new UnsupportedOperationException();\n}<\/code><\/pre>\n\u5f53\u6211\u4eec\u9700\u8981\u4e00\u4e2amap\u4e2d\u5305\u542bkey\u4e3aString\u7c7b\u578b\uff0cvalue\u4e3aList\u7c7b\u578b\u7684\u65f6\u5019\uff0c\u4ee5\u524d\u6211\u4eec\u662f\u8fd9\u6837\u5199\u7684<\/p>\n
Map<String,List<Integer>> map = new HashMap<String, List<Integer>>();\nList<Integer> list = new ArrayList<Integer>();\nlist.add(1);\nlist.add(2);\nmap.put("aa", list);\nSystem.out.println(map.get("aa")); \/\/[1, 2]<\/code><\/pre>\n\u800c\u73b0\u5728<\/p>\n
Multimap<String, Integer> map = ArrayListMultimap.create(); \nmap.put("aa", 1);\nmap.put("aa", 2);\nSystem.out.println(map.get("aa")); \/\/[1, 2]<\/code><\/pre>\n\u5176\u4ed6\u7684\u9ed1\u79d1\u6280\u96c6\u5408<\/p>\n
MultiSet: \u65e0\u5e8f+\u53ef\u91cd\u590d count()\u65b9\u6cd5\u83b7\u53d6\u5355\u8bcd\u7684\u6b21\u6570 \u589e\u5f3a\u4e86\u53ef\u8bfb\u6027+\u64cd\u4f5c\u7b80\u5355\n\u521b\u5efa\u65b9\u5f0f: Multiset<String> set = HashMultiset.create();\n\nMultimap: key-value key\u53ef\u4ee5\u91cd\u590d \n\u521b\u5efa\u65b9\u5f0f: Multimap<String, String> teachers = ArrayListMultimap.create();\n\nBiMap: \u53cc\u5411Map(Bidirectional Map) \u952e\u4e0e\u503c\u90fd\u4e0d\u80fd\u91cd\u590d\n\u521b\u5efa\u65b9\u5f0f: BiMap<String, String> biMap = HashBiMap.create();\n\nTable: \u53cc\u952e\u7684Map Map-->Table-->rowKey+columnKey+value \/\/\u548csql\u4e2d\u7684\u8054\u5408\u4e3b\u952e\u6709\u70b9\u50cf\n\u521b\u5efa\u65b9\u5f0f: Table<String, String, Integer> tables = HashBasedTable.create();\n\n...\u7b49\u7b49(guava\u4e2d\u8fd8\u6709\u5f88\u591ajava\u91cc\u9762\u6ca1\u6709\u7ed9\u51fa\u7684\u96c6\u5408\u7c7b\u578b)<\/code><\/pre>\n\u5c06\u96c6\u5408\u8f6c\u6362\u4e3a\u7279\u5b9a\u89c4\u5219\u7684\u5b57\u7b26\u4e32<\/h3>\n
\u4ee5\u524d\u6211\u4eec\u5c06list\u8f6c\u6362\u4e3a\u7279\u5b9a\u89c4\u5219\u7684\u5b57\u7b26\u4e32\u662f\u8fd9\u6837\u5199\u7684:<\/p>\n
\/\/use java\nList<String> list = new ArrayList<String>();\nlist.add("aa");\nlist.add("bb");\nlist.add("cc");\nString str = "";\nfor(int i=0; i<list.size(); i++){\n str = str + "-" +list.get(i);\n}\n\/\/str \u4e3a-aa-bb-cc\n\n\/\/use guava\nList<String> list = new ArrayList<String>();\nlist.add("aa");\nlist.add("bb");\nlist.add("cc");\nString result = Joiner.on("-").join(list);\n\/\/result\u4e3a aa-bb-cc<\/code><\/pre>\n\u628amap\u96c6\u5408\u8f6c\u6362\u4e3a\u7279\u5b9a\u89c4\u5219\u7684\u5b57\u7b26\u4e32<\/p>\n
Map<String, Integer> map = Maps.newHashMap();\nmap.put("xiaoming", 12);\nmap.put("xiaohong", 13);\nString result = Joiner.on(",").withKeyValueSeparator("=").join(map);\n\/\/ result\u4e3a xiaoming=12,xiaohong=13<\/code><\/pre>\n\u5c06String\u8f6c\u6362\u4e3a\u7279\u5b9a\u7684\u96c6\u5408<\/h3>\n\/\/use java\nList<String> list = new ArrayList<String>();\nString a = "1-2-3-4-5-6";\nString[] strs = a.split("-");\nfor (int i=0; i<strs.length; i++) {\n list.add(strs[i]);\n}\n\n\/\/use guava\nString str = "1-2-3-4-5-6";\nList<String> list = Splitter.on("-").splitToList(str);\n\/\/list\u4e3a [1, 2, 3, 4, 5, 6]<\/code><\/pre>\n\u5982\u679c<\/p>\n
str="1-2-3-4- 5- 6 ";<\/code><\/pre>\nguava\u8fd8\u53ef\u4ee5\u4f7f\u7528omitEmptyStrings().trimResults()<\/code>\u53bb\u9664\u7a7a\u4e32\u4e0e\u7a7a\u683c<\/p>\nString str = "1-2-3-4- 5- 6 "; \nList<String> list = Splitter.on("-").omitEmptyStrings().trimResults().splitToList(str);\nSystem.out.println(list);<\/code><\/pre>\n\u5c06String\u8f6c\u6362\u4e3amap<\/p>\n
String str = "xiaoming=11,xiaohong=23";\nMap<String,String> map = Splitter.on(",").withKeyValueSeparator("=").split(str);<\/code><\/pre>\nguava\u8fd8\u652f\u6301\u591a\u4e2a\u5b57\u7b26\u5207\u5272\uff0c\u6216\u8005\u7279\u5b9a\u7684\u6b63\u5219\u5206\u9694<\/p>\n
String input = "aa.dd,,ff,,.";\nList<String> result = Splitter.onPattern("[.|,]").omitEmptyStrings().splitToList(input);<\/code><\/pre>\n\u5b57\u7b26\u4e32\u5339\u914d\u64cd\u4f5c<\/h3>\n
\u5173\u4e8e\u5b57\u7b26\u4e32\u7684\u5339\u914d\u64cd\u4f5c\uff0c\u90fd\u662f\u5728CharMatcher\u8fd9\u4e2a\u7c7b\u4e0a\u8fdb\u884c\u7684<\/p>\n
\/\/ \u5224\u65ad\u5339\u914d\u7ed3\u679c\nboolean result = CharMatcher.inRange('a', 'z').or(CharMatcher.inRange('A', 'Z')).matches('K'); \/\/true\n\n\/\/ \u4fdd\u7559\u6570\u5b57\u6587\u672c CharMatcher.digit() \u5df2\u8fc7\u65f6 retain \u4fdd\u7559\n\/\/String s1 = CharMatcher.digit().retainFrom("abc 123 efg"); \/\/123\nString s1 = CharMatcher.inRange('0', '9').retainFrom("abc 123 efg"); \/\/ 123\n\n\/\/ \u5220\u9664\u6570\u5b57\u6587\u672c remove \u5220\u9664\n\/\/ String s2 = CharMatcher.digit().removeFrom("abc 123 efg"); \/\/abc efg\nString s2 = CharMatcher.inRange('0', '9').removeFrom("abc 123 efg"); \/\/ abc efg<\/code><\/pre>\n\u96c6\u5408\u7684\u8fc7\u6ee4<\/h3>\n
\u6211\u4eec\u5bf9\u4e8e\u96c6\u5408\u7684\u8fc7\u6ee4\uff0c\u601d\u8def\u5c31\u662f\u8fed\u4ee3\uff0c\u7136\u540e\u518d\u5177\u4f53\u5bf9\u6bcf\u4e00\u4e2a\u6570\u5224\u65ad\uff0c\u8fd9\u6837\u7684\u4ee3\u7801\u653e\u5728\u7a0b\u5e8f\u4e2d\uff0c\u96be\u514d\u4f1a\u663e\u5f97\u5f88\u81c3\u80bf\uff0c\u867d\u7136\u529f\u80fd\u90fd\u6709\uff0c\u4f46\u662f\u5f88\u4e0d\u597d\u770b\u3002<\/p>\n
\/\/guava\u5199\u6cd5\n\/\/\u6309\u7167\u6761\u4ef6\u8fc7\u6ee4\nImmutableList<String> names = ImmutableList.of("begin", "code", "Guava", "Java");\nIterable<String> fitered = Iterables.filter(names, Predicates.or(Predicates.equalTo("Guava"), Predicates.equalTo("Java")));\nSystem.out.println(fitered); \/\/ [Guava, Java]\n\n\/\/\u81ea\u5b9a\u4e49\u8fc7\u6ee4\u6761\u4ef6 \u4f7f\u7528\u81ea\u5b9a\u4e49\u56de\u8c03\u65b9\u6cd5\u5bf9Map\u7684\u6bcf\u4e2aValue\u8fdb\u884c\u64cd\u4f5c\nImmutableMap<String, Integer> m = ImmutableMap.of("begin", 12, "code", 15);\n\/\/ Function<F, T> F\u8868\u793aapply()\u65b9\u6cd5input\u7684\u7c7b\u578b\uff0cT\u8868\u793aapply()\u65b9\u6cd5\u8fd4\u56de\u7c7b\u578b\nMap<String, Integer> m2 = Maps.transformValues(m, new Function<Integer, Integer>() {\n public Integer apply(Integer input) {\n if (input > 12 ){\n return input;\n } else {\n return input+1;\n }\n }\n});\nSystem.out.println(m2); \/\/{begin=13, code=15}<\/code><\/pre>\nset\u7684\u4ea4\u96c6, \u5e76\u96c6, \u5dee\u96c6<\/p>\n
HashSet<Integer> setA = Sets.newHashSet(1, 2, 3, 4, 5);\nHashSet<Integer> setB = Sets.newHashSet(4, 5, 6, 7, 8);\n\nSets.SetView<Integer> union = Sets.union(setA, setB);\nSystem.out.println("union:");\nfor (Integer integer : union)\n System.out.println(integer); \/\/union \u5e76\u96c6: 12345867\n\nSets.SetView<Integer> difference = Sets.difference(setA, setB);\nSystem.out.println("difference:");\nfor (Integer integer : difference)\n System.out.println(integer); \/\/difference \u5dee\u96c6: 123\n\nSets.SetView<Integer> intersection = Sets.intersection(setA, setB);\nSystem.out.println("intersection:");\nfor (Integer integer : intersection)\n System.out.println(integer); \/\/intersection \u4ea4\u96c6: 45<\/code><\/pre>\nmap\u7684\u4ea4\u96c6\uff0c\u5e76\u96c6\uff0c\u5dee\u96c6<\/p>\n
HashMap<String, Integer> mapA = Maps.newHashMap();\nmapA.put("a", 1);mapA.put("b", 2);mapA.put("c", 3);\n\nHashMap<String, Integer> mapB = Maps.newHashMap();\nmapB.put("b", 20);mapB.put("c", 3);mapB.put("d", 4);\n\nMapDifference differenceMap = Maps.difference(mapA, mapB);\nSystem.out.println(differenceMap); \/\/not equal: only on left={a=1}: only on right={d=4}: value differences={b=(2, 20)}\ndifferenceMap.areEqual();\nMap entriesDiffering = differenceMap.entriesDiffering();\nMap entriesOnlyLeft = differenceMap.entriesOnlyOnLeft();\nMap entriesOnlyRight = differenceMap.entriesOnlyOnRight();\nMap entriesInCommon = differenceMap.entriesInCommon();\n\nSystem.out.println(entriesDiffering); \/\/ {b=(2, 20)}\nSystem.out.println(entriesOnlyLeft); \/\/ {a=1}\nSystem.out.println(entriesOnlyRight); \/\/ {d=4}\nSystem.out.println(entriesInCommon); \/\/ {c=3}<\/code><\/pre>\n\u68c0\u67e5\u53c2\u6570<\/h3>\n\/\/use java\nif (list!=null && list.size()>0)\n'''\nif (str!=null && str.length()>0)\n'''\nif (str !=null && !str.isEmpty())\n\n\/\/use guava\nif (!Strings.isNullOrEmpty(str))\n\n\/\/use java\nif (count <= 0) {\n throw new IllegalArgumentException("must be positive: " + count); \n} \n\n\/\/use guava\nPreconditions.checkArgument(count > 0, "must be positive: %s", count); <\/code><\/pre>\n\u68c0\u67e5\u662f\u5426\u4e3a\u7a7a\uff0c\u4e0d\u4ec5\u4ec5\u662f\u5b57\u7b26\u4e32\u7c7b\u578b\uff0c\u5176\u4ed6\u7c7b\u578b\u7684\u5224\u65ad\uff0c\u5168\u90e8\u90fd\u5c01\u88c5\u5728Preconditions<\/code>\u7c7b\u91cc\uff0c\u91cc\u9762\u7684\u65b9\u6cd5\u5168\u4e3a\u9759\u6001<\/p>\n\u5176\u4e2d\u7684\u4e00\u4e2a\u65b9\u6cd5\u7684\u6e90\u7801<\/p>\n
@CanIgnoreReturnValue\npublic static <T> T checkNotNull(T reference) {\n if (reference == null) {\n throw new NullPointerException();\n }\n return reference;\n}<\/code><\/pre>\n\n\n\n| \u65b9\u6cd5\u58f0\u660e\uff08\u4e0d\u5305\u62ec\u989d\u5916\u53c2\u6570\uff09<\/th>\n | \u63cf\u8ff0<\/th>\n | \u68c0\u67e5\u5931\u8d25\u65f6\u629b\u51fa\u7684\u5f02\u5e38<\/th>\n<\/tr>\n<\/thead>\n |
\n\ncheckArgument(boolean)<\/code><\/td>\n| \u68c0\u67e5boolean\u662f\u5426\u4e3atrue\uff0c\u7528\u6765\u68c0\u67e5\u4f20\u9012\u7ed9\u65b9\u6cd5\u7684\u53c2\u6570<\/td>\n | IllegalArgumentException<\/code><\/td>\n<\/tr>\n\ncheckNotNull(T)<\/code><\/td>\n| \u68c0\u67e5value\u662f\u5426\u4e3anull\uff0c\u8be5\u65b9\u6cd5\u76f4\u63a5\u8fd4\u56devalue\uff0c\u56e0\u6b64\u53ef\u4ee5\u5185\u5d4c\u4f7f\u7528checkNotNull<\/td>\n | NullPointerException<\/code><\/td>\n<\/tr>\n\ncheckState(boolean)<\/code><\/td>\n| \u7528\u6765\u68c0\u67e5\u5bf9\u8c61\u7684\u67d0\u4e9b\u72b6\u6001<\/td>\n | IllegalStateException<\/code><\/td>\n<\/tr>\n\ncheckElementIndex(int index, int size)<\/code><\/td>\n\u68c0\u67e5index\u4f5c\u4e3a\u7d22\u5f15\u503c\u5bf9\u67d0\u4e2a\u5217\u8868\u3001\u5b57\u7b26\u4e32\u6216\u6570\u7ec4\u662f\u5426\u6709\u6548\u3002
index > 0 && index < size<\/code><\/td>\nIndexOutOfBoundsException<\/code><\/td>\n<\/tr>\n\ncheckPositionIndexes(int start, int end, int size)<\/code><\/td>\n| \u68c0\u67e5[start,end]\u8868\u793a\u7684\u4f4d\u7f6e\u8303\u56f4\u5bf9\u67d0\u4e2a\u5217\u8868\u3001\u5b57\u7b26\u4e32\u6216\u6570\u7ec4\u662f\u5426\u6709\u6548<\/td>\n | IndexOutOfBoundsException<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\nMoreObjects<\/h3>\n\u8fd9\u4e2a\u65b9\u6cd5\u662f\u5728Objects\u8fc7\u671f\u540e\u5b98\u65b9\u63a8\u8350\u4f7f\u7528\u7684\u66ff\u4ee3\u54c1\uff0c\u8be5\u7c7b\u6700\u5927\u7684\u597d\u5904\u5c31\u662f\u4e0d\u7528\u5927\u91cf\u7684\u91cd\u5199toString<\/code>\uff0c\u7528\u4e00\u79cd\u5f88\u4f18\u96c5\u7684\u65b9\u5f0f\u5b9e\u73b0\u91cd\u5199\uff0c\u6216\u8005\u5728\u67d0\u4e2a\u573a\u666f\u5b9a\u5236\u4f7f\u7528\u3002<\/p>\nPerson person = new Person("aa", 11);\nString str = MoreObjects.toStringHelper("Person").add("age", person.getAge()).toString();\nSystem.out.println(str); \n\/\/\u8f93\u51faPerson{age=11}<\/code><\/pre>\n\u5f3a\u5927\u7684Ordering\u6392\u5e8f\u5668<\/h3>\n\u6392\u5e8f\u5668[Ordering]\u662fGuava\u6d41\u7545\u98ce\u683c\u6bd4\u8f83\u5668[Comparator]\u7684\u5b9e\u73b0\uff0c\u5b83\u53ef\u4ee5\u7528\u6765\u4e3a\u6784\u5efa\u590d\u6742\u7684\u6bd4\u8f83\u5668\uff0c\u4ee5\u5b8c\u6210\u96c6\u5408\u6392\u5e8f\u7684\u529f\u80fd\u3002<\/p>\n natural() \u5bf9\u53ef\u6392\u5e8f\u7c7b\u578b\u505a\u81ea\u7136\u6392\u5e8f\uff0c\u5982\u6570\u5b57\u6309\u5927\u5c0f\uff0c\u65e5\u671f\u6309\u5148\u540e\u6392\u5e8f\nusingToString() \u6309\u5bf9\u8c61\u7684\u5b57\u7b26\u4e32\u5f62\u5f0f\u505a\u5b57\u5178\u6392\u5e8f[lexicographical ordering]\nfrom(Comparator) \u628a\u7ed9\u5b9a\u7684Comparator\u8f6c\u5316\u4e3a\u6392\u5e8f\u5668\nreverse() \u83b7\u53d6\u8bed\u4e49\u76f8\u53cd\u7684\u6392\u5e8f\u5668\nnullsFirst() \u4f7f\u7528\u5f53\u524d\u6392\u5e8f\u5668\uff0c\u4f46\u989d\u5916\u628anull\u503c\u6392\u5230\u6700\u524d\u9762\nnullsLast() \u4f7f\u7528\u5f53\u524d\u6392\u5e8f\u5668\uff0c\u4f46\u989d\u5916\u628anull\u503c\u6392\u5230\u6700\u540e\u9762\ncompound(Comparator) \u5408\u6210\u53e6\u4e00\u4e2a\u6bd4\u8f83\u5668\uff0c\u4ee5\u5904\u7406\u5f53\u524d\u6392\u5e8f\u5668\u4e2d\u7684\u76f8\u7b49\u60c5\u51b5\nlexicographical() \u57fa\u4e8e\u5904\u7406\u7c7b\u578bT\u7684\u6392\u5e8f\u5668\uff0c\u8fd4\u56de\u8be5\u7c7b\u578b\u7684\u53ef\u8fed\u4ee3\u5bf9\u8c61Iterable<T>\u7684\u6392\u5e8f\u5668\nonResultOf(Function) \u5bf9\u96c6\u5408\u4e2d\u5143\u7d20\u8c03\u7528Function\uff0c\u518d\u6309\u8fd4\u56de\u503c\u7528\u5f53\u524d\u6392\u5e8f\u5668\u6392\u5e8f<\/code><\/pre>\n\u793a\u4f8b<\/p>\n Person person = new Person("aa", 14); \/\/String name, Integer age\nPerson ps = new Person("bb", 13);\nOrdering<Person> byOrdering = Ordering.natural().nullsFirst().onResultOf(new Function<Person, String>() {\n public String apply(Person person) {\n return person.age.toString();\n }\n});\nbyOrdering.compare(person, ps);\nSystem.out.println(byOrdering.compare(person, ps)); \/\/1\uff0cperson\u7684\u5e74\u9f84\u6bd4ps\u5927\uff0c\u6240\u4ee5\u8f93\u51fa1<\/code><\/pre>\n\u8ba1\u7b97\u4e2d\u95f4\u4ee3\u7801\u7684\u8fd0\u884c\u65f6\u95f4<\/h3>\nStopwatch stopwatch = Stopwatch.createStarted();\nfor (int i=0; i<100000; i++) {\n \/\/ do some thing\n}\nlong nanos = stopwatch.elapsed(TimeUnit.MILLISECONDS);\nSystem.out.println(nanos);<\/code><\/pre>\nTimeUnit \u53ef\u4ee5\u6307\u5b9a\u65f6\u95f4\u8f93\u51fa\u7cbe\u786e\u5230\u591a\u5c11\u65f6\u95f4<\/p>\n \u6587\u4ef6\u64cd\u4f5c<\/h3>\n\u4ee5\u524d\u6211\u4eec\u5199\u6587\u4ef6\u8bfb\u53d6\u7684\u65f6\u5019\u8981\u5b9a\u4e49\u7f13\u51b2\u533a\uff0c\u5404\u79cd\u6761\u4ef6\u5224\u65ad\uff0c\u800c\u73b0\u5728\u6211\u4eec\u53ea\u9700\u8981\u4f7f\u7528\u597dguava\u7684api \u5c31\u80fd\u4f7f\u4ee3\u7801\u53d8\u5f97\u7b80\u6d01\uff0c\u5e76\u4e14\u4e0d\u7528\u62c5\u5fc3\u56e0\u4e3a\u5199\u9519\u903b\u8f91\u800c\u80cc\u9505\u4e86<\/p>\n File file = new File("test.txt");\nList<String> list = null;\ntry {\n list = Files.readLines(file, Charsets.UTF_8);\n} catch (Exception e) {\n}\n\nFiles.copy(from, to); \/\/\u590d\u5236\u6587\u4ef6\nFiles.deleteDirectoryContents(File directory); \/\/\u5220\u9664\u6587\u4ef6\u5939\u4e0b\u7684\u5185\u5bb9(\u5305\u62ec\u6587\u4ef6\u4e0e\u5b50\u6587\u4ef6\u5939) \nFiles.deleteRecursively(File file); \/\/\u5220\u9664\u6587\u4ef6\u6216\u8005\u6587\u4ef6\u5939 \nFiles.move(File from, File to); \/\/\u79fb\u52a8\u6587\u4ef6\nURL url = Resources.getResource("abc.xml"); \/\/\u83b7\u53d6classpath\u6839\u4e0b\u7684abc.xml\u6587\u4ef6url\n\n\/\/\u6216\u8005\u4f7f\u7528\u5982\u4e0b\u7684\u64cd\u4f5c\nFiles.copy(from, to); \/\/\u590d\u5236\u6587\u4ef6\nPath path = Paths.get("\/home\/yezhou\/spring-boot-starter-hello\/src\/main\/resources\/config");\n\nMoreFiles.deleteDirectoryContents(path, RecursiveDeleteOption.ALLOW_INSECURE); \/\/\u5220\u9664\u6587\u4ef6\u5939\u4e0b\u7684\u5185\u5bb9(\u5305\u62ec\u6587\u4ef6\u4e0e\u5b50\u6587\u4ef6\u5939)\nMoreFiles.deleteRecursively(File file); \/\/\u5220\u9664\u6587\u4ef6\u6216\u8005\u6587\u4ef6\u5939\nMoreFiles.createParentDirectories(path); \/\/\u521b\u5efa\u7236\u76ee\u5f55<\/code><\/pre>\nFiles\u7c7b\u4e2d\u8fd8\u6709\u8bb8\u591a\u65b9\u6cd5\u53ef\u4ee5\u7528\uff0c\u53ef\u4ee5\u591a\u591a\u7ffb\u9605<\/p>\n guava\u7f13\u5b58<\/h3>\nguava\u7684\u7f13\u5b58\u8bbe\u8ba1\u7684\u6bd4\u8f83\u5de7\u5999\uff0c\u53ef\u4ee5\u5f88\u7cbe\u5de7\u7684\u4f7f\u7528\u3002guava\u7f13\u5b58\u521b\u5efa\u5206\u4e3a\u4e24\u79cd\uff0c\u4e00\u79cd\u662fCacheLoader\uff0c\u53e6\u4e00\u79cd\u5219\u662fcallback\u65b9\u5f0f<\/p>\n \uff081\uff09CacheLoader\u65b9\u5f0f<\/p>\n LoadingCache<String, String> cahceBuilder = CacheBuilder\n .newBuilder()\n .build(new CacheLoader<String, String>() {\n @Override\n public String load(String key) throws Exception {\n String strProValue = "hello " + key + "!";\n return strProValue;\n }\n });\nSystem.out.println(cahceBuilder.apply("begincode")); \/\/hello begincode!\nSystem.out.println(cahceBuilder.get("begincode")); \/\/hello begincode!\nSystem.out.println(cahceBuilder.get("wen")); \/\/hello wen!\nSystem.out.println(cahceBuilder.apply("wen")); \/\/hello wen!\nSystem.out.println(cahceBuilder.apply("da")); \/\/hello da!\ncahceBuilder.put("begin", "code");\nSystem.out.println(cahceBuilder.get("begin")); \/\/code<\/code><\/pre>\napi\u4e2d\u5df2\u7ecf\u628aapply\u58f0\u660e\u4e3a\u8fc7\u671f\uff0c\u58f0\u660e\u4e2d\u63a8\u8350\u4f7f\u7528get\u65b9\u6cd5\u83b7\u53d6\u503c<\/p>\n \uff082\uff09callback\u65b9\u5f0f<\/p>\n Cache<String, String> cache = CacheBuilder.newBuilder().maximumSize(1000).build();\nString resultVal = cache.get("code", new Callable<String>() {\n public String call() {\n String strProValue = "begin " + "code" + "!";\n return strProValue;\n }\n});\nSystem.out.println("value : " + resultVal); \/\/value : begin code!<\/code><\/pre>\n\u4ee5\u4e0a\u53ea\u662fguava\u4f7f\u7528\u7684\u4e00\u5c0f\u90e8\u5206\uff0cguava\u662f\u4e2a\u5927\u7684\u5de5\u5177\u7c7b\uff0c\u7b2c\u4e00\u7248guava\u662f2010\u5e74\u53d1\u5e03\u7684\uff0c\u6bcf\u4e00\u7248\u7684\u66f4\u65b0\u548c\u8fed\u4ee3\u90fd\u662f\u4e00\u79cd\u521b\u65b0\u3002<\/p>\n JDK\u7684\u5347\u7ea7\u5f88\u591a\u90fd\u662f\u501f\u9274guava\u91cc\u9762\u7684\u601d\u60f3\u6765\u8fdb\u884c\u7684\u3002<\/p>\n","protected":false},"excerpt":{"rendered":" \u6982\u8ff0 \u5de5\u5177\u7c7b\uff0c\u5c31\u662f\u5c01\u88c5\u5e73\u5e38\u7528\u7684\u65b9\u6cd5\uff0c\u4e0d\u9700\u8981\u91cd\u590d\u9020\u8f6e\u5b50\uff0c\u8282\u7701\u5f00\u53d1\u4eba\u5458\u65f6\u95f4\uff0c\u63d0\u9ad8\u5de5\u4f5c\u6548\u7387\u3002\u8c37\u6b4c\u4f5c\u4e3a\u5927\u516c\u53f8\uff0c\u5f53\u7136\u4f1a\u4ece […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[113],"class_list":["post-681","post","type-post","status-publish","format-standard","hentry","category-java","tag-guava"],"_links":{"self":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/681","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/comments?post=681"}],"version-history":[{"count":0,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/posts\/681\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/media?parent=681"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/categories?post=681"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appblog.cn\/index.php\/wp-json\/wp\/v2\/tags?post=681"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
| | | | | | | | | | |