Commons Lang 常用方法

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.lang.ArrayUtils;
import org.apache.commons.lang.CharSet;
import org.apache.commons.lang.CharSetUtils;
import org.apache.commons.lang.ClassUtils;
import org.apache.commons.lang.ObjectUtils;
import org.apache.commons.lang.RandomStringUtils;
import org.apache.commons.lang.SerializationUtils;
import org.apache.commons.lang.StringEscapeUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.SystemUtils;
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
import org.apache.commons.lang.math.NumberUtils;
import org.apache.commons.lang.time.DateFormatUtils;
import org.apache.commons.lang.time.DateUtils;
import org.apache.commons.lang.time.StopWatch;
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.escapeHtml(""));
		System.out.println("html:" + StringEscapeUtils.unescapeHtml("<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.stringToInt("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();
	}
}