Java常用工具类汇总附示例代码-APISpace

Java常用工具类汇总附示例代码

一、FileUtils

private static void fileUtilsTest() {

try {

//读取文件内容

String readFileToString = FileUtils.readFileToString(new File("D:\\guor\\data\\test20211022000000.txt"));

System.out.println(readFileToString);

//删除文件夹

FileUtils.deleteDirectory(new File("D:\\guor1\\data1"));

FileUtils.deleteQuietly(new File("D:\\guor\\data"));

//清空文件夹

FileUtils.cleanDirectory(new File("D:\\guor\\data"));

//判断文件内容是否一致

boolean contentEquals = FileUtils.contentEquals(new File("D:\\guor\\data\\test20211022000000.txt"), new File("D:\\guor\\data\\testNew20211021000000.txt"));

boolean contentEquals2 = FileUtils.contentEquals(new File("D:\\guor\\data\\中文20211021100000.txt"), new File("D:\\guor\\data\\中文New20211022100000.txt"));

System.out.println(contentEquals+","+contentEquals2);

//拷贝特定类型的文件

FileUtils.copyDirectory(new File("D:\\guor\\data"), new File("D:\\guor\\data2"), new FileFilter() {

@Override

public boolean accept(File pathname) {

if(pathname.getName().startsWith("test")) {

return true;

}

return false;

}

});

FileUtils.moveDirectory(new File("D:\\guor\\data"), new File("D:\\guor\\data3"));

FileUtils.moveFileToDirectory(new File("D:\\guor\\data"), new File("D:\\guor\\data3"), true);

FileUtils.moveToDirectory(new File("D:\\guor\\data"), new File("D:\\guor\\data4"), true);

boolean directoryContains = FileUtils.directoryContains(new File("D:\\guor\\data"), new File("D:\\guor\\data\\test20211022000000.txt"));

System.out.println(directoryContains);

directoryContains = FileUtils.directoryContains(new File("D:\\guor\\data"), new File("*.txt"));

System.out.println(directoryContains);

//获取某文件夹下特定格式文件

File[] listFiles = new File("D:\\guor\\data").listFiles(new FilenameFilter() {

@Override

public boolean accept(File dir, String name) {

return name.startsWith("test");

}

});

System.out.println(Arrays.toString(listFiles));

//获取系统temp文件夹路径

File tempDirectory = FileUtils.getTempDirectory();

System.out.println(tempDirectory);

//获取系统用户文件夹路径

File userDirectory = FileUtils.getUserDirectory();

System.out.println(userDirectory);

//查看是否是新建的文件夹

SimpleDateFormat sdf =new SimpleDateFormat("yyyyMMddHHmmss" );

Date parse = sdf.parse("20210206134900");

boolean fileNewer = FileUtils.isFileNewer(new File("D:\\guor\\data"), parse);

System.out.println(fileNewer);

//更新文件修改时间，如果不存在，则新建；

FileUtils.touch(new File("D:\\guor\\data\\test20211022000000.txt"));

//延迟查看文件是否存在

boolean waitFor = FileUtils.waitFor(new File("D:\\guor\\data\\testNew20211021000000.txt"), 5);

System.out.println(waitFor);

} catch (Exception e) {

System.out.println(e);

}

//根据文件修改时间排序

public static void test02() {

String dir = "D:\\data";

File[] listFiles = new File(dir).listFiles();

List asList = Arrays.asList(listFiles);

for(File file:listFiles) {

System.out.println(file);

}

Collections.sort(asList, new Comparator() {

@Override

public int compare(File o1, File o2) {

if(o1.lastModified()

return -1;

}else if(o1.lastModified()>o2.lastModified()) {

return 1;

}else {

return 0;

}

});

System.out.println("sort...");

for(File file:listFiles) {

System.out.println(file+","+file.lastModified());

}

二、StringUtil

private static void stringUtilsTest() {

String sthttp://r = "hello world";

//将第一个字符大写

String capitalize = StringUtils.capitalize(str);

System.out.println(capitalize);//Hello

//两边空格补齐

String center = StringUtils.center(str, 7);

System.out.println(center);// hello

String center = StringUtils.center(str, 7, "*");

System.out.println(center);//*hello*

//chomp剔除字符串最后一个是\n或\r\或\r\n

String chomp = StringUtils.chomp(str);

System.out.println(chomp);

//chop剔除字符串最后一个字符（如果最后一个是\n或\r\或\r\n也剔除掉）

String chop = StringUtils.chop(str);

System.out.println(chop);//hello worl

//是否包含任意字符

boolean containsAny = StringUtils.containsAny(str, "W");

System.out.println(containsAny);

//是否包含任意字符，忽略大小写

containsAny = StringUtils.containsIgnoreCase(str, "W");

System.out.println(containsAny);

//有意思

int indexOfAnyBut = StringUtils.indexOfAnyBut(str, "hello orld");

System.out.println(indexOfAnyBut);

//两个字符串从第几位开始不同

int indexOfDifference = StringUtils.indexOfDifference(str, str);

System.out.println(indexOfDifference);

indexOfDifference = StringUtils.indexOfDifference(str, str+"zs");

System.out.println(indexOfDifference);

indexOfDifference = StringUtils.indexOfDifference(str, "he llo");

System.out.println(indexOfDifference);

//判断是否是正整数

boolean isNumeric = StringUtils.isNumeric(str);

System.out.println(isNumeric);//false

isNumeric = StringUtils.isNumeric("1234dd");

System.out.println("1234dd:"+isNumeric);//false

isNumeric = StringUtils.isNumeric("1234 ");

System.out.println("1234 :"+isNumeric);//false

isNumeric = StringUtils.isNumeric("1.234");

System.out.println("1.234:"+isNumeric);//false

isNumeric = StringUtils.isNumeric("1234");

System.out.println("1234:" + isNumeric);//true

isNumeric = StringUtils.isNumeric("-1234");

System.out.println("-1234:" + isNumeric);//false

//判断是否是正整数或空格

boolean isNumeric = StringUtils.isNumericSpace(str);

//将数组变为字符串，并添加字符进行分割

Object[] array = new Object[] http://{"zs",18,"男",666,777};

String join = StringUtils.join(array);

System.out.println(Arrays.toString(array));

join = StringUtils.join(array, "*");

System.out.println(join);

Object[] array = new Object[] {"zs",18,"男",666,777};

String join = StringUtils.join(array, ";", 2, 5);

System.out.println(join);

String remove = StringUtils.remove(str, "hello");

System.out.println(remove);// world

String repeat = StringUtils.repeat(str, 3);

System.out.println(repeat);//hello worldhello worldhello world

repeat = StringUtils.repeat(str, ",", 3);

System.out.println(repeat);//hello world,hello world,hello world

//分别替换

String[] list = new String[] {"hello", "girl"};

String[] replacementList = new String[] {"say", "woman"};

String str2 = "hello world,hello boy,hello girl.";

String replaceEach = StringUtils.replaceEach(str2, list, replacementList);

System.out.println(replaceEach);//say world,say boy,say woman.

//只替换第一个匹配的字符串

String replaceOnce = StringUtils.replaceOnce("hello world,hello boy,hello girl.", "hello", "say");

System.out.println(replaceOnce);//say world,hello boy,hello girl.

//截取某字符后面的部分

String substringAfterLast = StringUtils.substringAfterLast("hello world,hello boy,hello girl.", " ");

System.out.println(substringAfterLast);//girl.

String substringBeforeLast = StringUtils.substringBeforeLast("hello world,hello boy,hello girl.", " ");

System.out.println(substringBeforeLast);//hello world,hello boy,hello

}

三、CollectionUtils

private static void collectionUtilsTest() {

List list = new ArrayList();

list.add("zhangsan");

list.add("dalian");

list.add("gateway");

list.add("28");

list.add("35");

//查找第一个符合条件的元素

Object find = CollectionUtils.find(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return false;

}

return true;

}

});

//排除不符合条件的元素

Collection select = CollectionUtils.select(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return false;

}

return true;

}

});

System.out.println(list);//[zhangsan, dalian, 28]

System.out.println(find);//zhangsan

System.out.println(select);//[zhangsan, dalian]

List list2 = new ArrayList();

list2.add("zhangsan");

list2.add("dalian2");

list2.add("282");

//查看两个集合中是否有相同的元素

boolean containsAny = CollectionUtils.containsAny(list, list2);

System.out.println(containsAny);//true

//查找集合中某元素的个数

int countMatches = CollectionUtils.countMatches(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return true;

}

return false;

}

});

System.out.println(countMatches);

//查找集合中是否存在某元素

boolean exists = CollectionUtils.exists(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return true;

}

return false;

}

});

SRoktugzystem.out.println(exists);

//删除集合中的某些元素

System.out.println(list);//[zhangsan, dalian, 打法, 28, 35]

CollectionUtils.filter(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return false;

}

return true;

}

});

System.out.println(list);//[zhangsan, dalian, 打法]

//查找集合中符合条件的第一个元素

Object find = CollectionUtils.find(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return false;

}

return true;

}

});

System.out.println(find);//zhangsan

//闭包回调函数

System.out.println(list);

CollectionUtils.forAllDo(list, new Closure() {

@Override

public void execute(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

work(arg0);

}

});

System.out.println(list);

//查找集合中元素的个数

System.out.println(list);//[zhangsan, dalian, gateway, gateway, 28, 35]

Map cardinalityMap = CollectionUtils.getCardinalityMap(list);

System.out.println(cardinalityMap);//{35=1, 28=1, zhangsan=1, dalian=1, gateway=2}

//查找两个集合中的相同元素

List list2 = new ArrayList();

list2.add("lisi");

list2.add("beijing");

list2.add("gateway");

list.add("19");

Collection intersection = CollectionUtils.intersection(list, list2);

System.out.println(intersection);

//获取两个List>中相同的部分，可以用于对比两个库中的相同表数据是否相等

List> list3 = new ArrayList>();

List> list4 = new ArrayList>();

Map map1 = new HashMap();

map1.put("name", "zhangsan");

map1.put("age", 18);

map1.put("address", "dalian");

Map map2 = new HashMap();

map2.put("name", "张三");

map2.put("age", "十八");

map2.put("address", "大连");

list3.add(map1);

list3.add(map2);

Map map3 = new HashMap();

map3.put("name", "李四");

map3.put("age", "十八");

map3.put("address", "大连");

list4.add(map2);

list4.add(map1);

list3.add(map3);

System.out.println(list3);

System.out.println(list4);

Collection intersection = CollectionUtils.intersection(list3, list4);

System.out.println(intersection);//[{address=dalian, name=zhangsan, age=18}]

//判断两个集合是否相同

boolean equalCollection = CollectionUtils.isEqualCollection(list3, list4);

System.out.println(equalCollection);

判断param2是否包含param1，且不能完全相同

System.out.println(list3);//[{address=dalian, name=zhangsan, age=18}, {address=大连, name=张三, age=十八}, {address=大连, name=李四, age=十八}]

System.out.println(list4);//[{address=大连, name=张三, age=十八}, {address=dalian, name=zhangsan, age=18}]

boolean properSubCollection = CollectionUtils.isProperSubCollection(list4, list3);

System.out.println(properSubCollection);//true

//断定某集合是否含有某元素，如果包含则抛异常（我觉得应该少用为妙）

System.out.println(list);//[zhangsan, dalian, gateway, gateway, 28, 35]

Collection predicatedCollection = CollectionUtils.predicatedCollection(list, new Predicate() {

@Override

public boolean evaluate(Object object) {

if(StringUtils.isNumeric(object.toString())) {

return false;

}

return true;

}

});

System.out.println(predicatedCollection);//Exception in thread "main" java.lang.IllegalArgumentException: Cannot add Object '28' - Predicate rejected it

List list2 = new ArrayList();

list2.add("gateway");

System.out.println(list);

System.out.println(list2);

//删除list1中的list2

Collection removeAll = CollectionUtils.removeAll(list, list2);

System.out.println(removeAll);

//反转数组

String[] array = new String[] {"zs","ls","ww"};

System.out.println(StringUtils.join(array, ","));//zs,ls,ww

CollectionUtils.reverseArray(array);

System.out.println(StringUtils.join(array, ","));//ww,ls,zs

删除list1中的list2

List list2 = new ArrayList();

list2.add("zhangsan");

list2.add("dalian");

Collection subtract = CollectionUtils.subtract(list, list2);

System.out.println(subtract);

//更改集合中的特定值

Collection collect = CollectionUtils.collect(list, new Transformer() {

@Override

public Object transform(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return 15;

}

return arg0;

}

});

System.out.println(list);//[zhangsan, dalian, 28, 35]

System.out.println(collect);//[zhangsan, dalian, 15, 15]

//更改集合中的特定值，改变集合本身

System.out.println(list);//[zhangsan, dalian, gateway, gateway, 28, 35]

CollectionUtils.transform(list, new Transformer() {

@Override

public Object transform(Object input) {

if(StringUtils.isNumeric(input.toString())) {

return 15;

}

return input;

}

});

System.out.println(list);//[zhangsan, dalian, gateway, gateway, 15, 15]

List list2 = new ArrayList();

list2.add("docker");

list2.add("zhangsan");

System.out.println(list);

System.out.println(list2);

//将list和list2中的元素合并，但去除list2中的重复元素

Collection union = CollectionUtils.union(list, list2);

System.out.println(union);

}

private static void work(Object obj){

System.out.println("闭包回调函数:我是数字，"+obj);

}

四、ArrayUtils

private static void arrayUtilsTest() {

String[] array =new String[] {"zs", "ls"};

//增加元素

Object[] add = ArrayUtils.add(array, "ww");

System.out.println(StringUtils.join(add, ","));//zs,ls,ww

//合并数组

String[] array2 =new String[] {"ww", "ss"};

Object[] addAll = ArrayUtils.addAll(array1, array2);

System.out.println(StringUtils.join(addAll, ","));//zs,ls,ww,ss

//克隆数组

Object[] clone = ArrayUtils.clone(array);

System.out.println(StringUtils.join(clone, ","));//zs,ls

boolean contains = ArrayUtils.contains(array, "ww");

boolean contains1 = ArrayUtils.contains(array, "zs");

System.out.println(contains+","+contains1);//false,true

}

return -1;

}else if(o1.lastModified()>o2.lastModified()) {

return 1;

}else {

return 0;

}

});

System.out.println("sort...");

for(File file:listFiles) {

System.out.println(file+","+file.lastModified());

}

二、StringUtil

private static void stringUtilsTest() {

String sthttp://r = "hello world";

//将第一个字符大写

String capitalize = StringUtils.capitalize(str);

System.out.println(capitalize);//Hello

//两边空格补齐

String center = StringUtils.center(str, 7);

System.out.println(center);// hello

String center = StringUtils.center(str, 7, "*");

System.out.println(center);//*hello*

//chomp剔除字符串最后一个是\n或\r\或\r\n

String chomp = StringUtils.chomp(str);

System.out.println(chomp);

//chop剔除字符串最后一个字符（如果最后一个是\n或\r\或\r\n也剔除掉）

String chop = StringUtils.chop(str);

System.out.println(chop);//hello worl

//是否包含任意字符

boolean containsAny = StringUtils.containsAny(str, "W");

System.out.println(containsAny);

//是否包含任意字符，忽略大小写

containsAny = StringUtils.containsIgnoreCase(str, "W");

System.out.println(containsAny);

//有意思

int indexOfAnyBut = StringUtils.indexOfAnyBut(str, "hello orld");

System.out.println(indexOfAnyBut);

//两个字符串从第几位开始不同

int indexOfDifference = StringUtils.indexOfDifference(str, str);

System.out.println(indexOfDifference);

indexOfDifference = StringUtils.indexOfDifference(str, str+"zs");

System.out.println(indexOfDifference);

indexOfDifference = StringUtils.indexOfDifference(str, "he llo");

System.out.println(indexOfDifference);

//判断是否是正整数

boolean isNumeric = StringUtils.isNumeric(str);

System.out.println(isNumeric);//false

isNumeric = StringUtils.isNumeric("1234dd");

System.out.println("1234dd:"+isNumeric);//false

isNumeric = StringUtils.isNumeric("1234 ");

System.out.println("1234 :"+isNumeric);//false

isNumeric = StringUtils.isNumeric("1.234");

System.out.println("1.234:"+isNumeric);//false

isNumeric = StringUtils.isNumeric("1234");

System.out.println("1234:" + isNumeric);//true

isNumeric = StringUtils.isNumeric("-1234");

System.out.println("-1234:" + isNumeric);//false

//判断是否是正整数或空格

boolean isNumeric = StringUtils.isNumericSpace(str);

//将数组变为字符串，并添加字符进行分割

Object[] array = new Object[] http://{"zs",18,"男",666,777};

String join = StringUtils.join(array);

System.out.println(Arrays.toString(array));

join = StringUtils.join(array, "*");

System.out.println(join);

Object[] array = new Object[] {"zs",18,"男",666,777};

String join = StringUtils.join(array, ";", 2, 5);

System.out.println(join);

String remove = StringUtils.remove(str, "hello");

System.out.println(remove);// world

String repeat = StringUtils.repeat(str, 3);

System.out.println(repeat);//hello worldhello worldhello world

repeat = StringUtils.repeat(str, ",", 3);

System.out.println(repeat);//hello world,hello world,hello world

//分别替换

String[] list = new String[] {"hello", "girl"};

String[] replacementList = new String[] {"say", "woman"};

String str2 = "hello world,hello boy,hello girl.";

String replaceEach = StringUtils.replaceEach(str2, list, replacementList);

System.out.println(replaceEach);//say world,say boy,say woman.

//只替换第一个匹配的字符串

String replaceOnce = StringUtils.replaceOnce("hello world,hello boy,hello girl.", "hello", "say");

System.out.println(replaceOnce);//say world,hello boy,hello girl.

//截取某字符后面的部分

String substringAfterLast = StringUtils.substringAfterLast("hello world,hello boy,hello girl.", " ");

System.out.println(substringAfterLast);//girl.

String substringBeforeLast = StringUtils.substringBeforeLast("hello world,hello boy,hello girl.", " ");

System.out.println(substringBeforeLast);//hello world,hello boy,hello

}

三、CollectionUtils

private static void collectionUtilsTest() {

List list = new ArrayList();

list.add("zhangsan");

list.add("dalian");

list.add("gateway");

list.add("28");

list.add("35");

//查找第一个符合条件的元素

Object find = CollectionUtils.find(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return false;

}

return true;

}

});

//排除不符合条件的元素

Collection select = CollectionUtils.select(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return false;

}

return true;

}

});

System.out.println(list);//[zhangsan, dalian, 28]

System.out.println(find);//zhangsan

System.out.println(select);//[zhangsan, dalian]

List list2 = new ArrayList();

list2.add("zhangsan");

list2.add("dalian2");

list2.add("282");

//查看两个集合中是否有相同的元素

boolean containsAny = CollectionUtils.containsAny(list, list2);

System.out.println(containsAny);//true

//查找集合中某元素的个数

int countMatches = CollectionUtils.countMatches(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return true;

}

return false;

}

});

System.out.println(countMatches);

//查找集合中是否存在某元素

boolean exists = CollectionUtils.exists(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return true;

}

return false;

}

});

SRoktugzystem.out.println(exists);

//删除集合中的某些元素

System.out.println(list);//[zhangsan, dalian, 打法, 28, 35]

CollectionUtils.filter(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return false;

}

return true;

}

});

System.out.println(list);//[zhangsan, dalian, 打法]

//查找集合中符合条件的第一个元素

Object find = CollectionUtils.find(list, new Predicate() {

@Override

public boolean evaluate(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return false;

}

return true;

}

});

System.out.println(find);//zhangsan

//闭包回调函数

System.out.println(list);

CollectionUtils.forAllDo(list, new Closure() {

@Override

public void execute(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

work(arg0);

}

});

System.out.println(list);

//查找集合中元素的个数

System.out.println(list);//[zhangsan, dalian, gateway, gateway, 28, 35]

Map cardinalityMap = CollectionUtils.getCardinalityMap(list);

System.out.println(cardinalityMap);//{35=1, 28=1, zhangsan=1, dalian=1, gateway=2}

//查找两个集合中的相同元素

List list2 = new ArrayList();

list2.add("lisi");

list2.add("beijing");

list2.add("gateway");

list.add("19");

Collection intersection = CollectionUtils.intersection(list, list2);

System.out.println(intersection);

//获取两个List>中相同的部分，可以用于对比两个库中的相同表数据是否相等

List> list3 = new ArrayList>();

List> list4 = new ArrayList>();

Map map1 = new HashMap();

map1.put("name", "zhangsan");

map1.put("age", 18);

map1.put("address", "dalian");

Map map2 = new HashMap();

map2.put("name", "张三");

map2.put("age", "十八");

map2.put("address", "大连");

list3.add(map1);

list3.add(map2);

Map map3 = new HashMap();

map3.put("name", "李四");

map3.put("age", "十八");

map3.put("address", "大连");

list4.add(map2);

list4.add(map1);

list3.add(map3);

System.out.println(list3);

System.out.println(list4);

Collection intersection = CollectionUtils.intersection(list3, list4);

System.out.println(intersection);//[{address=dalian, name=zhangsan, age=18}]

//判断两个集合是否相同

boolean equalCollection = CollectionUtils.isEqualCollection(list3, list4);

System.out.println(equalCollection);

判断param2是否包含param1，且不能完全相同

System.out.println(list3);//[{address=dalian, name=zhangsan, age=18}, {address=大连, name=张三, age=十八}, {address=大连, name=李四, age=十八}]

System.out.println(list4);//[{address=大连, name=张三, age=十八}, {address=dalian, name=zhangsan, age=18}]

boolean properSubCollection = CollectionUtils.isProperSubCollection(list4, list3);

System.out.println(properSubCollection);//true

//断定某集合是否含有某元素，如果包含则抛异常（我觉得应该少用为妙）

System.out.println(list);//[zhangsan, dalian, gateway, gateway, 28, 35]

Collection predicatedCollection = CollectionUtils.predicatedCollection(list, new Predicate() {

@Override

public boolean evaluate(Object object) {

if(StringUtils.isNumeric(object.toString())) {

return false;

}

return true;

}

});

System.out.println(predicatedCollection);//Exception in thread "main" java.lang.IllegalArgumentException: Cannot add Object '28' - Predicate rejected it

List list2 = new ArrayList();

list2.add("gateway");

System.out.println(list);

System.out.println(list2);

//删除list1中的list2

Collection removeAll = CollectionUtils.removeAll(list, list2);

System.out.println(removeAll);

//反转数组

String[] array = new String[] {"zs","ls","ww"};

System.out.println(StringUtils.join(array, ","));//zs,ls,ww

CollectionUtils.reverseArray(array);

System.out.println(StringUtils.join(array, ","));//ww,ls,zs

删除list1中的list2

List list2 = new ArrayList();

list2.add("zhangsan");

list2.add("dalian");

Collection subtract = CollectionUtils.subtract(list, list2);

System.out.println(subtract);

//更改集合中的特定值

Collection collect = CollectionUtils.collect(list, new Transformer() {

@Override

public Object transform(Object arg0) {

if(StringUtils.isNumeric(arg0.toString())) {

return 15;

}

return arg0;

}

});

System.out.println(list);//[zhangsan, dalian, 28, 35]

System.out.println(collect);//[zhangsan, dalian, 15, 15]

//更改集合中的特定值，改变集合本身

System.out.println(list);//[zhangsan, dalian, gateway, gateway, 28, 35]

CollectionUtils.transform(list, new Transformer() {

@Override

public Object transform(Object input) {

if(StringUtils.isNumeric(input.toString())) {

return 15;

}

return input;

}

});

System.out.println(list);//[zhangsan, dalian, gateway, gateway, 15, 15]

List list2 = new ArrayList();

list2.add("docker");

list2.add("zhangsan");

System.out.println(list);

System.out.println(list2);

//将list和list2中的元素合并，但去除list2中的重复元素

Collection union = CollectionUtils.union(list, list2);

System.out.println(union);

}

private static void work(Object obj){

System.out.println("闭包回调函数:我是数字，"+obj);

}

四、ArrayUtils

private static void arrayUtilsTest() {

String[] array =new String[] {"zs", "ls"};

//增加元素

Object[] add = ArrayUtils.add(array, "ww");

System.out.println(StringUtils.join(add, ","));//zs,ls,ww

//合并数组

String[] array2 =new String[] {"ww", "ss"};

Object[] addAll = ArrayUtils.addAll(array1, array2);

System.out.println(StringUtils.join(addAll, ","));//zs,ls,ww,ss

//克隆数组

Object[] clone = ArrayUtils.clone(array);

System.out.println(StringUtils.join(clone, ","));//zs,ls

boolean contains = ArrayUtils.contains(array, "ww");

boolean contains1 = ArrayUtils.contains(array, "zs");

System.out.println(contains+","+contains1);//false,true

}

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