Apache Commons 常用工具类整理
所需的Maven依赖
commons-codec
commons-codec
1.10
org.apache.commons
commons-collections4
4.1
commons-configuration
commons-configuration
1.10
- 从一个entity中把属性复制进另外一个entity中
@Test
public void testCopyNewBean() throws Exception {
StuForm form = new StuForm("lee", 18, 1, new Date(), true);
Stu stu = new Stu();
BeanUtils.copyProperties(form, stu);
System.out.println(stu.toString());
}
- base64 加密解密
@Test
public void testBase64Code() throws Exception {
String name1 = "hello, my name is lee~";
System.out.println("Before: " + name1);
String name2 = Base64.encodeBase64String(name1.getBytes());
System.out.println("After encode: " + name2);
String name3 = new String(Base64.decodeBase64(name2));
System.out.println("After decode: " + name3);
String url1 = "www.lee.com.cn";
System.out.println("URL Before: " + url1);
String url2 = Base64.encodeBase64URLSafeString(url1.getBytes());
System.out.println("URL After decode: " + url2);
String url3 = new String(Base64.decodeBase64(url2));
System.out.println("URL After decode: " + url3);
}
- commons 下 collection 工具包
@Test
public void testCollection() throws Exception {
OrderedMap om = new LinkedMap();
om.put("one", 1);
om.put("two", "2");
om.put("three", "three");
om.put("fore", 4);
om.put("five", "5");
System.out.println(om.firstKey());
System.out.println(om.nextKey("fore"));
System.out.println(om.previousKey("five"));
System.out.println("==============================");
BidiMap bm = new TreeBidiMap();
bm.put("three", "3");
bm.put("five", "isfive");
System.out.println(bm.getKey("isfive").toString());
System.out.println(bm.get("three"));
// 交换key和value
BidiMap newMap = bm.inverseBidiMap();
System.out.println(newMap.size());
System.out.println("==============================");
Bag
- Apache Commons Configuration
@Test
public void testConfig() throws Exception {
PropertiesConfiguration p = new PropertiesConfiguration("test.properties");
System.out.println(p.getString("boy.name"));
System.out.println(p.getInt("boy.age"));
System.out.println(p.getString("boy.birth"));
p.setHeader("##this is a new string##");
p.setProperty("new.string", "newString");
// 保存在编译后的目录中
p.save();
p.save("newP");
}
- Apache Commons Lang
@Test
public void testLang() throws Exception {
String a1[] = {"1", "2", "3"};
String a2[] = {"a", "b", "c"};
// 合并数组
String a3[] = (String[])ArrayUtils.addAll(a1, a2);
for (String s : a3) {
System.out.println(s);
}
System.out.println("==============================");
String str = "hello, my name is hanmeimei! what's your name? name";
// 出现第一个和第二个name之间的string
String s1 = StringUtils.substringBetween(str, "name");
System.out.println("s1: " + s1);
// 截取第一次出现的字符串之间的string
String s2 = StringUtils.substringBetween(str, "name", "your");
System.out.println("s2: " + s2);
// StringUtils.substringAfter(str, separator)
// StringUtils.substringBefore(str, separator)
System.out.println("==============================");
// 判断该字符串是不是为数字(0~9)组成，如果是，返回true 但该方法不识别有小数点
System.out.println(StringUtils.isNumeric("454534"));
System.out.println("==============================");
System.out.println(ClassUtils.getShortClassName(Test.class));
System.out.println(ClassUtils.getPackageName(Test.class));
System.out.println("==============================");
// 判断该字符串是不是为数字(0~9)组成，如果是，返回true 可以识别有小数点
System.out.println(NumberUtils.isNumber("12334.11"));
// 不建议使用，可以使用 Integer.valueOf("[number]")
System.out.println(NumberUtils.stringToInt("33"));
System.out.println(Integer.valueOf("33"));
// 五位的随机字母和数字
System.out.println(RandomStringUtils.randomAlphanumeric(5));
System.out.println(StringEscapeUtils.escapeHtml(""));
System.out.println(StringEscapeUtils.escapeJava("String"));
// StringUtils,判断是否是空格字符
System.out.println(StringUtils.isBlank(" "));
// StringUtils.isEmpty("");
// 将数组中的内容以,分隔
System.out.println(StringUtils.join(a3, ","));
// 在右边加下字符,使之总长度为6
System.out.println(StringUtils.rightPad("abc", 6, 'T'));
// 首字母大写
System.out.println(StringUtils.capitalize("abc"));
// Deletes all whitespaces from a String 删除所有空格
System.out.println(StringUtils.deleteWhitespace(" ab c "));
// 判断是否包含这个字符
System.out.println(StringUtils.contains("abc", "ba"));
// 表示左边两个字符
System.out.println(StringUtils.left("abc", 2));
}
}