org.apache.commons.lang3功能示例

package com.hbk.test; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.util.Calendar; import java.util.Date; import java.util.Iterator; import org.apache.commons.lang3.ArrayUtils; import org.apache.commons.lang3.CharSet; import org.apache.commons.lang3.CharSetUtils; import org.apache.commons.lang3.ClassUtils; import org.apache.commons.lang3.ObjectUtils; import org.apache.commons.lang3.RandomStringUtils; import org.apache.commons.lang3.SerializationUtils; import org.apache.commons.lang3.StringUtils; import org.apache.commons.lang3.SystemUtils; import org.apache.commons.lang3.builder.EqualsBuilder; import org.apache.commons.lang3.builder.HashCodeBuilder; import org.apache.commons.lang3.builder.ToStringBuilder; import org.apache.commons.lang3.builder.ToStringStyle; import org.apache.commons.lang3.math.NumberUtils; import org.apache.commons.lang3.time.DateFormatUtils; import org.apache.commons.lang3.time.DateUtils; import org.apache.commons.lang3.time.StopWatch; import org.apache.commons.lang3.StringEscapeUtils; /** * @author Administrator *http://commons.apache.org/proper/commons-lang/userguide.html */ public class LangDemo { public void charSetDemo() { System.out.println("**CharSetDemo**"); CharSet charSet = CharSet.getInstance("aeiou"); String demoStr = "The quick brown fox jumps over the lazy dog."; int count = 0; for (int i = 0, len = demoStr.length(); i < len; i++) { if (charSet.contains(demoStr.charAt(i))) { count++; } } System.out.println("count: " + count); } public void charSetUtilsDemo() { System.out.println("**CharSetUtilsDemo**"); System.out.println("计算字符串中包含某字符数."); System.out.println(CharSetUtils.count( "The quick brown fox jumps over the lazy dog.", "aeiou")); System.out.println("删除字符串中某字符."); System.out.println(CharSetUtils.delete( "The quick brown fox jumps over the lazy dog.", "aeiou")); System.out.println("保留字符串中某字符."); System.out.println(CharSetUtils.keep( "The quick brown fox jumps over the lazy dog.", "aeiou")); System.out.println("合并重复的字符."); System.out.println(CharSetUtils.squeeze("a bbbbbb c dd", "b d")); } public void objectUtilsDemo() { System.out.println("**ObjectUtilsDemo**"); System.out.println("Object为null时，默认打印某字符."); Object obj = null; System.out.println(ObjectUtils.defaultIfNull(obj, "空")); System.out.println("验证两个引用是否指向的Object是否相等,取决于Object的equals()方法."); Object a = new Object(); Object b = a; Object c = new Object(); System.out.println(ObjectUtils.equals(a, b)); System.out.println(ObjectUtils.equals(a, c)); System.out.println("用父类Object的toString()方法返回对象信息."); Date date = new Date(); System.out.println(ObjectUtils.identityToString(date)); System.out.println(date); System.out.println("返回类本身的toString()方法结果,对象为null时，返回0长度字符串."); System.out.println(ObjectUtils.toString(date)); System.out.println(ObjectUtils.toString(null)); System.out.println(date); } public void serializationUtilsDemo() { System.out.println("*SerializationUtils**"); Date date = new Date(); byte[] bytes = SerializationUtils.serialize(date); System.out.println(ArrayUtils.toString(bytes)); System.out.println(date); Date reDate = (Date) SerializationUtils.deserialize(bytes); System.out.println(reDate); System.out.println(ObjectUtils.equals(date, reDate)); System.out.println(date == reDate); FileOutputStream fos = null; FileInputStream fis = null; try { fos = new FileOutputStream(new File("d:/test.txt")); fis = new FileInputStream(new File("d:/test.txt")); SerializationUtils.serialize(date, fos); Date reDate2 = (Date) SerializationUtils.deserialize(fis); System.out.println(date.equals(reDate2)); } catch (FileNotFoundException e) { e.printStackTrace(); } finally { try { fos.close(); fis.close(); } catch (IOException e) { e.printStackTrace(); } } } public void randomStringUtilsDemo() { System.out.println("**RandomStringUtilsDemo**"); System.out.println("生成指定长度的随机字符串,好像没什么用."); System.out.println(RandomStringUtils.random(500)); System.out.println("在指定字符串中生成长度为n的随机字符串."); System.out.println(RandomStringUtils.random(5, "abcdefghijk")); System.out.println("指定从字符或数字中生成随机字符串."); System.out.println(RandomStringUtils.random(5, true, false)); System.out.println(RandomStringUtils.random(5, false, true)); } public void stringUtilsDemo() { System.out.println("**StringUtilsDemo**"); System.out.println("将字符串重复n次，将文字按某宽度居中，将字符串数组用某字符串连接."); String[] header = new String[3]; header[0] = StringUtils.repeat("*", 50); header[1] = StringUtils.center(" StringUtilsDemo ", 50, "^O^"); header[2] = header[0]; String head = StringUtils.join(header, "/n"); System.out.println(head); System.out.println("缩短到某长度,用...结尾."); System.out.println(StringUtils.abbreviate( "The quick brown fox jumps over the lazy dog.", 10)); System.out.println(StringUtils.abbreviate( "The quick brown fox jumps over the lazy dog.", 15, 10)); System.out.println("返回两字符串不同处索引号."); System.out.println(StringUtils.indexOfDifference("aaabc", "aaacc")); System.out.println("返回两字符串不同处开始至结束."); System.out.println(StringUtils.difference("aaabcde", "aaaccde")); System.out.println("截去字符串为以指定字符串结尾的部分."); System.out.println(StringUtils.chomp("aaabcde", "de")); System.out.println("检查一字符串是否为另一字符串的子集."); System.out.println(StringUtils.containsOnly("aad", "aadd")); System.out.println("检查一字符串是否不是另一字符串的子集."); System.out.println(StringUtils.containsNone("defg", "aadd")); System.out.println("检查一字符串是否包含另一字符串."); System.out.println(StringUtils.contains("defg", "ef")); System.out.println(StringUtils.containsOnly("ef", "defg")); System.out.println("返回可以处理null的toString()."); System.out.println(StringUtils.defaultString("aaaa")); System.out.println("?" + StringUtils.defaultString(null) + "!"); System.out.println("去除字符中的空格."); System.out.println(StringUtils.deleteWhitespace("aa bb cc")); System.out.println("判断是否是某类字符."); System.out.println(StringUtils.isAlpha("ab")); System.out.println(StringUtils.isAlphanumeric("12")); System.out.println(StringUtils.isBlank("")); System.out.println(StringUtils.isNumeric("123")); } public void systemUtilsDemo() { System.out.println(genHeader("SystemUtilsDemo")); System.out.println("获得系统文件分隔符."); System.out.println(SystemUtils.FILE_SEPARATOR); System.out.println("获得源文件编码."); System.out.println(SystemUtils.FILE_ENCODING); System.out.println("获得ext目录."); System.out.println(SystemUtils.JAVA_EXT_DIRS); System.out.println("获得java版本."); System.out.println(SystemUtils.JAVA_VM_VERSION); System.out.println("获得java厂商."); System.out.println(SystemUtils.JAVA_VENDOR); } public void classUtilsDemo() { System.out.println(genHeader("ClassUtilsDemo")); System.out.println("获取类实现的所有接口."); System.out.println(ClassUtils.getAllInterfaces(Date.class)); System.out.println("获取类所有父类."); System.out.println(ClassUtils.getAllSuperclasses(Date.class)); System.out.println("获取简单类名."); System.out.println(ClassUtils.getShortClassName(Date.class)); System.out.println("获取包名."); System.out.println(ClassUtils.getPackageName(Date.class)); System.out.println("判断是否可以转型."); System.out.println(ClassUtils.isAssignable(Date.class, Object.class)); System.out.println(ClassUtils.isAssignable(Object.class, Date.class)); } public void stringEscapeUtilsDemo() { System.out.println(genHeader("StringEcsapeUtils")); System.out.println("转换特殊字符."); System.out.println("html:" + StringEscapeUtils.escapeHtml4("/n\n")); System.out.println("html:" + StringEscapeUtils.unescapeHtml4("<p>")); } private final class BuildDemo { String name; int age; public BuildDemo(String name, int age) { this.name = name; this.age = age; } public String toString() { ToStringBuilder tsb = new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE); tsb.append("Name", name); tsb.append("Age", age); return tsb.toString(); } public int hashCode() { HashCodeBuilder hcb = new HashCodeBuilder(); hcb.append(name); hcb.append(age); return hcb.hashCode(); } public boolean equals(Object obj) { if (!(obj instanceof BuildDemo)) { return false; } BuildDemo bd = (BuildDemo) obj; EqualsBuilder eb = new EqualsBuilder(); eb.append(name, bd.name); eb.append(age, bd.age); return eb.isEquals(); } } public void builderDemo() { System.out.println(genHeader("BuilderDemo")); BuildDemo obj1 = new BuildDemo("a", 1); BuildDemo obj2 = new BuildDemo("b", 2); BuildDemo obj3 = new BuildDemo("a", 1); System.out.println("toString()"); System.out.println(obj1); System.out.println(obj2); System.out.println(obj3); System.out.println("hashCode()"); System.out.println(obj1.hashCode()); System.out.println(obj2.hashCode()); System.out.println(obj3.hashCode()); System.out.println("equals()"); System.out.println(obj1.equals(obj2)); System.out.println(obj1.equals(obj3)); } public void numberUtils() { System.out.println(genHeader("NumberUtils")); System.out.println("字符串转为数字(不知道有什么用)."); System.out.println(NumberUtils.toInt("ba", 33)); System.out.println("从数组中选出最大值."); System.out.println(NumberUtils.max(new int[] { 1, 2, 3, 4 })); System.out.println("判断字符串是否全是整数."); System.out.println(NumberUtils.isDigits("123.1")); System.out.println("判断字符串是否是有效数字."); System.out.println(NumberUtils.isNumber("0123.1")); } public void dateFormatUtilsDemo() { System.out.println(genHeader("DateFormatUtilsDemo")); System.out.println("格式化日期输出."); System.out.println(DateFormatUtils.format(System.currentTimeMillis(), "yyyy-MM-dd HH:mm:ss")); System.out.println("秒表."); StopWatch sw = new StopWatch(); sw.start(); for (Iterator iterator = DateUtils.iterator(new Date(), DateUtils.RANGE_WEEK_CENTER); iterator.hasNext();) { Calendar cal = (Calendar) iterator.next(); System.out.println(DateFormatUtils.format(cal.getTime(), "yy-MM-dd HH:mm")); } sw.stop(); System.out.println("秒表计时:" + sw.getTime()); } private String genHeader(String head) { String[] header = new String[3]; header[0] = StringUtils.repeat("*", 50); header[1] = StringUtils.center(" " + head + " ", 50, "^O^"); header[2] = header[0]; return StringUtils.join(header, "/n"); } /** * @param args */ public static void main(String[] args) { LangDemo langDemo = new LangDemo(); langDemo.charSetDemo(); langDemo.charSetUtilsDemo(); langDemo.objectUtilsDemo(); langDemo.serializationUtilsDemo(); langDemo.randomStringUtilsDemo(); langDemo.stringUtilsDemo(); langDemo.systemUtilsDemo(); langDemo.classUtilsDemo(); langDemo.stringEscapeUtilsDemo(); langDemo.builderDemo(); langDemo.numberUtils(); langDemo.dateFormatUtilsDemo(); } }