commons-lang3的一些应用

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(DateFormatUtils.format(new Date(), "yyyy-MM-dd")
);
		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();
	}

}

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转载自shihuan830619.iteye.com/blog/1159938