Java常用工具类（二）org.apache.commons.lang
/**
* 1、字符串的空判断 org.aphche.commons.lang.StringUtils
/**
* 2、字符串的Trim
*/
* 3、字符串的分割
*/
/**
* 5、字符串的Escape org.apache.commons.lang.StringEscapeUtils
*/
/**
* 6、随机数 org.apache.commons.lang.RandomStringUtils
*/
/**
* 7、数组 org.apache.commons.lang.ArrayUtils
*/
/**
* 8、日期 org.apache.commons.lang.time.DateUtils
*/
* 1、字符串的空判断 org.aphche.commons.lang.StringUtils
*/
// Checks if a String is empty ("") or null.
System.out.println(StringUtils.isEmpty(null)); // true
System.out.println(StringUtils.isEmpty("")); // true
System.out.println(StringUtils.isEmpty(" ")); // false
System.out.println(StringUtils.isEmpty("bob")); // false
System.out.println(StringUtils.isEmpty(" bob ")); // false
// Checks if a String is whitespace, empty ("") or null.
System.out.println(StringUtils.isBlank(null)); // true
System.out.println(StringUtils.isBlank("")); // true
System.out.println(StringUtils.isBlank(" ")); // true
System.out.println(StringUtils.isBlank("bob")); // false
System.out.println(StringUtils.isBlank(" bob ")); // false
/**
* 2、字符串的Trim
*/
// The String is trimmed using String.trim(). Trim removes start and end characters <= 32. To strip whitespace use strip(String).
System.out.println(StringUtils.trim(null)); // null
System.out.println(StringUtils.trim("")); // ""
System.out.println(StringUtils.trim(" ")); // ""
System.out.println(StringUtils.trim("abc")); // "abc"
System.out.println(StringUtils.trim(" abc")); // "abc"
System.out.println(StringUtils.trim(" abc ")); // "abc"
System.out.println(StringUtils.trim(" ab c ")); // "ab c"
// Strips whitespace from the start and end of a String.
System.out.println(StringUtils.strip(null)); // null
System.out.println(StringUtils.strip("")); // ""
System.out.println(StringUtils.strip(" ")); // ""
System.out.println(StringUtils.strip("abc")); // "abc"
System.out.println(StringUtils.strip(" abc")); // "abc"
System.out.println(StringUtils.strip("abc ")); // "abc"
System.out.println(StringUtils.strip(" abc ")); // "abc"
System.out.println(StringUtils.strip(" ab c ")); // "ab c"
// strip(String,String);
System.out.println(StringUtils.strip(" abcyx", "xyz")); // " abc"
System.out.println(StringUtils.strip(null, "*")); // null
System.out.println(StringUtils.strip("", "*"));// ""
System.out.println(StringUtils.strip("abc", null)); // "abc"
System.out.println(StringUtils.strip(" abc", null)); // "abc"
System.out.println(StringUtils.strip("abc ", null)); // "abc"
System.out.println(StringUtils.strip(" abc ", null)); // "abc"
System.out.println(StringUtils.strip(" abcyx", "xyz")); // " abc"
// Strips any of a set of characters from the start of a String.
System.out.println(StringUtils.stripStart("yxabcxyz ", "xyz")); // "abcxyz "
// Strips any of a set of characters from the end of a String.
System.out.println(StringUtils.stripEnd(" xyzabcyx", "xyz")); // " xyzabc"
* 3、字符串的分割
*/
//默认半角空格分割
String str1 = "aaa bbb ccc";
String[] dim1 = StringUtils.split(str1); // => ["aaa", "bbb", "ccc"]
System.out.println(StringUtils.split("abc def")); // ["abc", "def"]
System.out.println(StringUtils.split("abc def")); // ["abc", "def"]
System.out.println(StringUtils.split(" abc ")); // ["abc"]
//指定分隔符
String str2 = "aaa,bbb,ccc";
String[] dim2 = StringUtils.split(str2, ","); // => ["aaa", "bbb", "ccc"]
//去除空字符串
String str3 = "aaa,,bbb";
String[] dim3 = StringUtils.split(str3, ","); // => ["aaa", "bbb"]
System.out.println(dim3.length);//2
System.out.println(dim3[0]);//"aaa"
System.out.println(dim3[1]);//"bbb"
//包含空字符串
String str4 = "aaa,,bbb";
String[] dim4 = StringUtils.splitPreserveAllTokens(str4, ","); // => ["aaa", "", "bbb"]
System.out.println(StringUtils.splitPreserveAllTokens("::cd:ef", ":"));// ["", "", cd", "ef"]
System.out.println(StringUtils.splitPreserveAllTokens(":cd:ef:", ":"));// ["", cd", "ef", ""]
//Splits the provided text into an array with a maximum length.
//A zero or negative value implies no limit
String str5 = "aaa,bbb,ccc";
String[] dim5 = StringUtils.split(str5, ",", 2); // => ["aaa", "bbb,ccc"]
System.out.println(StringUtils.split("ab:cd:ef", ":", 0));//["ab", "cd", "ef"]
System.out.println(StringUtils.split("ab:cd:ef", ":", 2));//["ab", "cd:ef"]
/**
* 4、字符串的连接
*/
//数组元素拼接
String[] array = {"aaa", "bbb", "ccc"};
StringUtils.join(array, ","); //"aaa,bbb,ccc"
StringUtils.join(array, "--");// "aaa--bbb--ccc"
StringUtils.join(array, "");//"aaabbbccc"
//集合元素拼接,the separator character to use, null treated as "".
List<String> list = new ArrayList<String>();
list.add("aaa");
list.add("bbb");
list.add("ccc");
StringUtils.join(list, ","); //"aaa,bbb,ccc"
/**
* 5、字符串的Escape org.apache.commons.lang.StringEscapeUtils
*/
System.out.println(StringEscapeUtils.escapeCsv("测试测试哦"));//"测试测试哦"
System.out.println(StringEscapeUtils.escapeCsv("测试,测试哦"));//"\"测试,测试哦\""
System.out.println(StringEscapeUtils.escapeCsv("测试\n测试哦"));//"\"测试\n测试哦\""
// System.out.println(StringEscapeUtils.escapeHtml4("测试测试哦"));//"<p>测试测试哦</p>"
System.out.println(StringEscapeUtils.escapeJava("\"rensaninng\"，欢迎您！"));//"\"rensaninng\"\uFF0C\u6B22\u8FCE\u60A8\uFF01"
// System.out.println(StringEscapeUtils.escapeEcmaScript("测试'测试哦"));//"\u6D4B\u8BD5\'\u6D4B\u8BD5\u54E6"
System.out.println(StringEscapeUtils.escapeXml("<tt>\"bread\" & \"butter\"</tt>"));//"<tt>"bread" & "butter"</tt>"
/**
* 6、随机数 org.apache.commons.lang.RandomStringUtils
*/
// 10位英字 System.out.println(RandomStringUtils.randomAlphabetic(10)); // 10位英数 System.out.println(RandomStringUtils.randomAlphanumeric(10)); // 10位ASCII码 System.out.println(RandomStringUtils.randomAscii(10)); // 指定文字10位 System.out.println(RandomStringUtils.random(10, "abcde"));
/**
* 7、数组 org.apache.commons.lang.ArrayUtils
*/
// 追加元素到数组尾部
int[] array1 = {1, 2};
array1 = ArrayUtils.add(array1, 3); // => [1, 2, 3]
System.out.println(array1.length);//3
System.out.println(array1[2]);//3
// 删除指定位置的元素
int[] array2 = {1, 2, 3};
array2 = ArrayUtils.remove(array2, 2); // => [1, 2]
System.out.println(array2.length);//2
// 截取部分元素 The start index is inclusive, the end index exclusive.
int[] array3 = {1, 2, 3, 4};
array3 = ArrayUtils.subarray(array3, 1, 3); // => [2, 3]
System.out.println(array3.length);//2
// 数组拷贝
String[] array4 = {"aaa", "bbb", "ccc"};
String[] copied = (String[]) ArrayUtils.clone(array4); // => {"aaa", "bbb", "ccc"}
System.out.println(copied.length);//3
// 判断是否包含某元素 Checks if the object is in the given array.
String[] array5 = {"aaa", "bbb", "ccc", "bbb"};
boolean result1 = ArrayUtils.contains(array5, "bbb"); // => true
System.out.println(result1);//true
// 判断某元素在数组中出现的位置（从前往后，没有返回-1）
int result2 = ArrayUtils.indexOf(array5, "bbb"); // => 1
System.out.println(result2);//1
// 判断某元素在数组中出现的位置（从后往前，没有返回-1）
int result3 = ArrayUtils.lastIndexOf(array5, "bbb"); // => 3
System.out.println(result3);//3
// 数组转Map
Map<Object, Object> map = ArrayUtils.toMap(new String[][]{
{"key1", "value1"},
{"key2", "value2"}
});
System.out.println(map.get("key1"));//"value1"
System.out.println(map.get("key2"));//"value2"
// 判断数组是否为空
Object[] array61 = new Object[0];
Object[] array62 = null;
Object[] array63 = new Object[]{"aaa"};
System.out.println(ArrayUtils.isEmpty(array61));//true Checks if an array of Objects is empty or null.
System.out.println(ArrayUtils.isEmpty(array62));//true
System.out.println(ArrayUtils.isNotEmpty(array63));//true true if the array is not empty or not null
// 判断数组长度是否相等
Object[] array71 = new Object[]{"aa", "bb", "cc"};
Object[] array72 = new Object[]{"dd", "ee", "ff"};
System.out.println(ArrayUtils.isSameLength(array71, array72));//true
// 判断数组元素内容是否相等
Object[] array81 = new Object[]{"aa", "bb", "cc"};
Object[] array82 = new Object[]{"aa", "bb", "cc"};
System.out.println(ArrayUtils.isEquals(array81, array82));
// Integer[] 转化为 int[]
Integer[] array9 = new Integer[]{1, 2};
int[] result = ArrayUtils.toPrimitive(array9);
System.out.println(result.length);//2
System.out.println(result[0]);//1
// int[] 转化为 Integer[]
int[] array10 = new int[]{1, 2};
Integer[] result10 = ArrayUtils.toObject(array10);
System.out.println(result.length);//2
System.out.println(result10[0].intValue());//1
/**
* 8、日期 org.apache.commons.lang.time.DateUtils
*/
// 生成Date对象
Date date = DateUtils.parseDate("2010/01/01 11:22:33", new String[]{"yyyy/MM/dd HH:mm:ss"});
// 10天后
Date tenDaysAfter = DateUtils.addDays(date, 10); // => 2010/01/11 11:22:33
System.out.println(DateFormatUtils.format(tenDaysAfter, "yyyy/MM/dd HH:mm:ss"));
// 前一个月
Date prevMonth = DateUtils.addMonths(date, -1); // => 2009/12/01 11:22:33
System.out.println(DateFormatUtils.format(prevMonth, "yyyy/MM/dd HH:mm:ss"));
// 判断是否是同一天
Date date1 = DateUtils.parseDate("2010/01/01 11:22:33", new String[]{"yyyy/MM/dd HH:mm:ss"});
Date date2 = DateUtils.parseDate("2010/01/01 22:33:44", new String[]{"yyyy/MM/dd HH:mm:ss"});
System.out.println(DateUtils.isSameDay(date1, date2));// true
// 日期格式化
System.out.println(DateFormatUtils.format(new Date(), "yyyy/MM/dd HH:mm:ss"));