Apache Commons Lang 包（包括SerializationUtils，ToStringBuilder，EqualsBuilder，HashCodeBuilder等类，待补充）

Apache Commons Lang 包是用来处理Java基本对象方法的工具类包，可以简化很多平时经常要用到的写法。比如：

1. SerializationUtils类：为序列化工具类，也是lang包下的工具，主要用于序列化操作，同时提供对象克隆接口
2. ToStringBuilder类：功能就是在自己定义一个类的toString 方法时，方便的格式化类的属性。ToStringBuilder类中的append方法可以向该类添加基本类型、数组和对象 ，只有添加的方法才会被toString方法输出。ToStringStyle类则是对输出的内容进行格式化。
3. EqualsBuilder与HashCodeBuilder类：可以简化Java类中equals与hashCode方法的改写过程。

 

下面是一个使用了各个工具的小例子：

 

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.StringEscapeUtils;  
 import org.apache.commons.lang3.StringUtils;  
 import org.apache.commons.lang3.SystemUtils;  
 import org.apache.commons.lang3.Validate;  
 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.text.WordUtils;  
 import org.apache.commons.lang3.time.DateFormatUtils;  
 import org.apache.commons.lang3.time.DateUtils;  
 import org.apache.commons.lang3.time.StopWatch;  
   
 public class TestLangDemo {  
   
     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("分隔符处理成数组.");  
         String[] strArray = StringUtils.split("a,b,,c,d,null,e", ",");  
         System.out.println(strArray.length);  
         System.out.println(strArray.toString());  
           
         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.escapeHtml3(" "));  
         System.out.println("html:" + StringEscapeUtils.escapeHtml4(" "));  
         System.out.println("html:" + StringEscapeUtils.unescapeHtml3("<p>"));  
         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");  
     }  
   
     private void validateDemo(){  
         String[] strarray = {"a", "b", "c"};  
         System.out.println("验证功能");  
         System.out.println(Validate.notEmpty(strarray));  
     }  
       
     private void wordUtilsDemo(){  
         System.out.println("单词处理功能");  
         String str1 = "wOrD";  
         String str2 = "ghj\nui\tpo";  
         System.out.println(WordUtils.capitalize(str1));  //首字母大写  
         System.out.println(WordUtils.capitalizeFully(str1));  //首字母大写其它字母小写  
         char[] ctrg = {'.'};  
         System.out.println(WordUtils.capitalizeFully("i aM.fine", ctrg));  //在规则地方转换  
         System.out.println(WordUtils.initials(str1));  //获取首字母  
         System.out.println(WordUtils.initials("Ben John Lee", null));  //取每个单词的首字母  
         char[] ctr = {' ', '.'};  
         System.out.println(WordUtils.initials("Ben J.Lee", ctr));  //按指定规则获取首字母  
         System.out.println(WordUtils.swapCase(str1));  //大小写逆转  
         System.out.println(WordUtils.wrap(str2, 1));  //解析\n和\t等字符  
     }  
       
     /** 
      * @param args 
      */  
     public static void main(String[] args) {  
         TestLangDemo langDemo = new TestLangDemo();  
   
         langDemo.charSetDemo();  
         langDemo.charSetUtilsDemo();  
         langDemo.objectUtilsDemo();  
         langDemo.serializationUtilsDemo();  
         langDemo.randomStringUtilsDemo();  
         langDemo.stringUtilsDemo();  
         langDemo.systemUtilsDemo();  
         langDemo.classUtilsDemo();  
         langDemo.stringEscapeUtilsDemo();  
         langDemo.builderDemo();  
         langDemo.numberUtils();  
         langDemo.dateFormatUtilsDemo();  
         langDemo.validateDemo();  
         langDemo.wordUtilsDemo();  
     }  
   
 }