Apache Commons包估计是Java中使用最广发的工具包了,很多框架都依赖于这组工具包中的一部分,它提供了我们常用的一些编程需要,但是JDK没能提供的机能,最大化的减少重复代码的编写。
http://commons.apache.org/
1)Commons Lang是对JDK中java.lang包的补充,提供了各种各样的Utilities工具类,这里说说最常用的几个工具类。
版本:commons-lang3-3.1.jar
1、字符串的空判断
1. //isEmpty
2. System.out.println(StringUtils.isEmpty(null)); // true
3. System.out.println(StringUtils.isEmpty("")); // true
4. System.out.println(StringUtils.isEmpty(" ")); // false
5. System.out.println(StringUtils.isEmpty("bob")); // false
6. System.out.println(StringUtils.isEmpty(" bob ")); // false
7.
8. //isBlank
9. System.out.println(StringUtils.isBlank(null)); // true
10. System.out.println(StringUtils.isBlank("")); // true
11. System.out.println(StringUtils.isBlank(" ")); // true
12. System.out.println(StringUtils.isBlank("bob")); // false
13. System.out.println(StringUtils.isBlank(" bob ")); // false
2、字符串的Trim
1. //trim
2. System.out.println(StringUtils.trim(null)); // null
3. System.out.println(StringUtils.trim("")); // ""
4. System.out.println(StringUtils.trim(" ")); // ""
5. System.out.println(StringUtils.trim("abc")); // "abc"
6. System.out.println(StringUtils.trim(" abc")); // "abc"
7. System.out.println(StringUtils.trim(" abc ")); // "abc"
8. System.out.println(StringUtils.trim(" ab c ")); // "ab c"
9.
10. //strip
11. System.out.println(StringUtils.strip(null)); // null
12. System.out.println(StringUtils.strip("")); // ""
13. System.out.println(StringUtils.strip(" ")); // ""
14. System.out.println(StringUtils.strip("abc")); // "abc"
15. System.out.println(StringUtils.strip(" abc")); // "abc"
16. System.out.println(StringUtils.strip("abc ")); // "abc"
17. System.out.println(StringUtils.strip(" abc ")); // "abc"
18. System.out.println(StringUtils.strip(" ab c ")); // "ab c"
19.
20. System.out.println(StringUtils.strip(" abcyx", "xyz")); // " abc"
21.
22. System.out.println(StringUtils.stripStart("yxabcxyz ", "xyz")); // "abcxyz "
23. System.out.println(StringUtils.stripEnd(" xyzabcyx", "xyz")); // " xyzabc"
3、字符串的分割
1. //默认半角空格分割
2. String str1 = "aaa bbb ccc";
3. String[] dim1 = StringUtils.split(str1); // => ["aaa", "bbb", "ccc"]
4.
5. System.out.println(dim1.length);//3
6. System.out.println(dim1[0]);//"aaa"
7. System.out.println(dim1[1]);//"bbb"
8. System.out.println(dim1[2]);//"ccc"
9.
10. //指定分隔符
11. String str2 = "aaa,bbb,ccc";
12. String[] dim2 = StringUtils.split(str2, ","); // => ["aaa", "bbb", "ccc"]
13.
14. System.out.println(dim2.length);//3
15. System.out.println(dim2[0]);//"aaa"
16. System.out.println(dim2[1]);//"bbb"
17. System.out.println(dim2[2]);//"ccc"
18.
19. //去除空字符串
20. String str3 = "aaa,,bbb";
21. String[] dim3 = StringUtils.split(str3, ","); // => ["aaa", "bbb"]
22.
23. System.out.println(dim3.length);//2
24. System.out.println(dim3[0]);//"aaa"
25. System.out.println(dim3[1]);//"bbb"
26.
27. //包含空字符串
28. String str4 = "aaa,,bbb";
29. String[] dim4 = StringUtils.splitPreserveAllTokens(str4, ","); // => ["aaa", "", "bbb"]
30.
31. System.out.println(dim4.length);//3
32. System.out.println(dim4[0]);//"aaa"
33. System.out.println(dim4[1]);//""
34. System.out.println(dim4[2]);//"bbb"
35.
36. //指定分割的最大次数(超过后不分割)
37. String str5 = "aaa,bbb,ccc";
38. String[] dim5 = StringUtils.split(str5, ",", 2); // => ["aaa", "bbb,ccc"]
39.
40. System.out.println(dim5.length);//2
41. System.out.println(dim5[0]);//"aaa"
42. System.out.println(dim5[1]);//"bbb,ccc"
4、字符串的连接
1. //数组元素拼接
2. String[] array = {"aaa", "bbb", "ccc"};
3. String result1 = StringUtils.join(array, ",");
4.
5. System.out.println(result1);//"aaa,bbb,ccc"
6.
7. //集合元素拼接
8. List<String> list = new
9. list.add("aaa");
10. list.add("bbb");
11. list.add("ccc");
12. String result2 = StringUtils.join(list, ",");
13.
14. System.out.println(result2);//"aaa,bbb,ccc"
5、字符串的Escape
1. System.out.println(StringEscapeUtils.escapeCsv("测试测试哦"));//"测试测试哦"
2. System.out.println(StringEscapeUtils.escapeCsv("测试,测试哦"));//"\"测试,测试哦\""
3. System.out.println(StringEscapeUtils.escapeCsv("测试\n测试哦"));//"\"测试\n测试哦\""
4.
5. System.out.println(StringEscapeUtils.escapeHtml4("测试测试哦
6. "));//"<p>测试测试哦</p>"
7. System.out.println(StringEscapeUtils.escapeJava("\"rensaninng\",欢迎您!"));//"\"rensaninng\"\uFF0C\u6B22\u8FCE\u60A8\uFF01"
8.
9. System.out.println(StringEscapeUtils.escapeEcmaScript("测试'测试哦"));//"\u6D4B\u8BD5\'\u6D4B\u8BD5\u54E6"
10. System.out.println(StringEscapeUtils.escapeXml("<tt>\"bread\" & \"butter\"</tt>"));//"<tt>"bread" & "butter"</tt>"
6、随机数
1. // 10位英字
2. System.out.println(RandomStringUtils.randomAlphabetic(10));
3.
4. // 10位英数
5. System.out.println(RandomStringUtils.randomAlphanumeric(10));
6.
7. // 10位ASCII码
8. System.out.println(RandomStringUtils.randomAscii(10));
9.
10. // 指定文字10位
11. System.out.println(RandomStringUtils.random(10, "abcde"));
7、数组
1. // 追加元素到数组尾部
2. int[] array1 = {1, 2};
3. array1 = ArrayUtils.add(array1, 3); // => [1, 2, 3]
4.
5. System.out.println(array1.length);//3
6. System.out.println(array1[2]);//3
7.
8. // 删除指定位置的元素
9. int[] array2 = {1, 2, 3};
10. array2 = ArrayUtils.remove(array2, 2); // => [1, 2]
11.
12. System.out.println(array2.length);//2
13.
14. // 截取部分元素
15. int[] array3 = {1, 2, 3, 4};
16. array3 = ArrayUtils.subarray(array3, 1, 3); // => [2, 3]
17.
18. System.out.println(array3.length);//2
19.
20. // 数组拷贝
21. String[] array4 = {"aaa", "bbb", "ccc"};
22. String[] copied = (String[]) ArrayUtils.clone(array4); // => {"aaa", "bbb", "ccc"}
23.
24. System.out.println(copied.length);//3
25.
26. // 判断是否包含某元素
27. String[] array5 = {"aaa", "bbb", "ccc", "bbb"};
28. boolean result1 = ArrayUtils.contains(array5, "bbb"); // => true
29. System.out.println(result1);//true
30.
31. // 判断某元素在数组中出现的位置(从前往后,没有返回-1)
32. int result2 = ArrayUtils.indexOf(array5, "bbb"); // => 1
33. System.out.println(result2);//1
34.
35. // 判断某元素在数组中出现的位置(从后往前,没有返回-1)
36. int result3 = ArrayUtils.lastIndexOf(array5, "bbb"); // => 3
37. System.out.println(result3);//3
38.
39. // 数组转Map
40. Map<Object, Object> map = ArrayUtils.toMap(new
41. "key1", "value1"},
42. "key2", "value2"}
43. });
44. System.out.println(map.get("key1"));//"value1"
45. System.out.println(map.get("key2"));//"value2"
46.
47. // 判断数组是否为空
48. Object[] array61 = new Object[0];
49. Object[] array62 = null;
50. Object[] array63 = new Object[]{"aaa"};
51.
52. System.out.println(ArrayUtils.isEmpty(array61));//true
53. System.out.println(ArrayUtils.isEmpty(array62));//true
54. System.out.println(ArrayUtils.isNotEmpty(array63));//true
55.
56. // 判断数组长度是否相等
57. Object[] array71 = new Object[]{"aa", "bb", "cc"};
58. Object[] array72 = new Object[]{"dd", "ee", "ff"};
59.
60. System.out.println(ArrayUtils.isSameLength(array71, array72));//true
61.
62. // 判断数组元素内容是否相等
63. Object[] array81 = new Object[]{"aa", "bb", "cc"};
64. Object[] array82 = new Object[]{"aa", "bb", "cc"};
65.
66. System.out.println(ArrayUtils.isEquals(array81, array82));
67.
68. // Integer[] 转化为 int[]
69. Integer[] array9 = new Integer[]{1, 2};
70. int[] result = ArrayUtils.toPrimitive(array9);
71.
72. System.out.println(result.length);//2
73. System.out.println(result[0]);//1
74.
75. // int[] 转化为 Integer[]
76. int[] array10 = new int[]{1, 2};
77. Integer[] result10 = ArrayUtils.toObject(array10);
78.
79. System.out.println(result.length);//2
80. System.out.println(result10[0].intValue());//1
8、日期
1. // 生成Date对象
2. Date date = DateUtils.parseDate("2010/01/01 11:22:33", new String[]{"yyyy/MM/dd HH:mm:ss"});
3.
4. // 10天后
5. Date tenDaysAfter = DateUtils.addDays(date, 10); // => 2010/01/11 11:22:33
6. System.out.println(DateFormatUtils.format(tenDaysAfter, "yyyy/MM/dd HH:mm:ss"));
7.
8. // 前一个月
9. Date prevMonth = DateUtils.addMonths(date, -1); // => 2009/12/01 11:22:33
10. System.out.println(DateFormatUtils.format(prevMonth, "yyyy/MM/dd HH:mm:ss"));
11.
12. // 判断是否是同一天
13. Date date1 = DateUtils.parseDate("2010/01/01 11:22:33", new String[]{"yyyy/MM/dd HH:mm:ss"});
14. Date date2 = DateUtils.parseDate("2010/01/01 22:33:44", new String[]{"yyyy/MM/dd HH:mm:ss"});
15. System.out.println(DateUtils.isSameDay(date1, date2));// true
16.
17. // 日期格式化
18. System.out.println(DateFormatUtils.format(new Date(), "yyyy/MM/dd HH:mm:ss"));
2)Commons Beanutils是一组专门用于操作Bean的工具类,目前很多流行的框架基本都离不开他。
版本:commons-beanutils-1.8.3.jar
1、获取字段值
1. SampleBean bean1 = new
2. bean1.setName("rensanning");
3. bean1.setAge(31);
4.
5. String name = BeanUtils.getProperty(bean1, "name");
6. String age = BeanUtils.getProperty(bean1, "age");
7.
8. System.out.println(name);
9. System.out.println(age);
2、设置字段值
1. SampleBean bean2 = new
2. BeanUtils.setProperty(bean2, "name", "rensanning");
3. BeanUtils.setProperty(bean2, "age", 31);
4.
5. System.out.println(bean2.getName());
6. System.out.println(bean2.getAge());
3、赋值Bean
1. SampleBean bean3 = new
2. bean3.setName("rensanning");
3. bean3.setAge(31);
4.
5. SampleBean clone = (SampleBean) BeanUtils.cloneBean(bean3);
6.
7. System.out.println(clone.getName());
8. System.out.println(clone.getAge());
4、Bean的describe
1. SampleBean bean4 = new
2. bean4.setName("rensanning");
3. bean4.setAge(31);
4.
5. @SuppressWarnings("unchecked")
6. Map<String, String> map4 = BeanUtils.describe(bean4);
7.
8. System.out.println(map4.get("name"));
9. System.out.println(map4.get("age"));
5、Bean的populate
6、获取Bean的数组集合字段值
1. SampleBean bean5 = new
2.
3. Map<String, String> map5 = new
4. map5.put("name", "rensanning");
5. map5.put("age", "31");
6.
7. BeanUtils.populate(bean5, map5);
8.
9. System.out.println(bean5.getName());
10. System.out.println(bean5.getAge());
1. SampleBean bean6 = new
2. bean6.setArray(new String[]{"a", "b", "c"});
3. List<String> list0 = new
4. list0.add("d");
5. list0.add("e");
6. list0.add("f");
7. bean6.setList(list0);
8.
9. String[] array = BeanUtils.getArrayProperty(bean6, "array");
10.
11. System.out.println(array.length);//3
12. System.out.println(array[0]);//"a"
13. System.out.println(array[1]);//"b"
14. System.out.println(array[2]);//"c"
15.
16. String[] list = BeanUtils.getArrayProperty(bean6, "list");
17. System.out.println(list.length);//3
18. System.out.println(list[0]);//"d"
19. System.out.println(list[1]);//"e"
20. System.out.println(list[2]);//"f"
21.
22. System.out.println(BeanUtils.getProperty(bean6, "array[1]"));//"b"
23. System.out.println(BeanUtils.getIndexedProperty(bean6, "array", 2));//"c"
7、获取Bean的Map字段值
8、获取Bean的嵌套字段值
1. SampleBean bean7 = new
2. Map<String, String> map = new
3. map.put("key1", "value1");
4. map.put("key2", "value2");
5. bean7.setMap(map);
6.
7. String value1 = BeanUtils.getMappedProperty(bean7, "map", "key1");
8. System.out.println(value1);//"value1"
9.
10. String value2 = BeanUtils.getMappedProperty(bean7, "map", "key2");
11. System.out.println(value2);//"value2"
12.
13. System.out.println(BeanUtils.getProperty(bean7, "map.key1"));//"value1"
14. System.out.println(BeanUtils.getProperty(bean7, "map.key2"));//"value2"
1. SampleBean bean = new
2. NestedBean nestedBean = new
3. nestedBean.setNestedProperty("xxx");
4. bean.setNestedBean(nestedBean);
5.
6. String value = BeanUtils.getNestedProperty(bean, "nestedBean.nestedProperty");
7. System.out.println(value);//"xxx"
8.
9. System.out.println(BeanUtils.getProperty(bean, "nestedBean.nestedProperty"));//"xxx"
9、URL字段的特殊处理
1. SampleBean bean8 = new
2.
3. BeanUtils.setProperty(bean8, "url", "http://www.google.com/");
4.
5. URL url = bean8.getUrl();
6. System.out.println(url.getProtocol());//"http"
7. System.out.println(url.getHost());//"www.google.com"
8. System.out.println(url.getPath());//"/"
10、日期的转化
1. SampleBean bean9 = new
2.
3. DateConverter converter = new
4. converter.setPattern("yyyy/MM/dd HH:mm:ss");
5.
6. ConvertUtils.register(converter, Date.class);
7. ConvertUtils.register(converter, String.class);
8.
9. BeanUtils.setProperty(bean9, "date", "2010/12/19 23:40:00");
10.
11. String value9 = BeanUtils.getProperty(bean9, "date");
12. System.out.println(value9);//"2010/12/19 23:40:00"
Jodd的BeanUtil也提供了相当方便的操作Bean的API。