Apache Commons Lang包的常用方法总结

[java]代码库

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;

/*转自霸气的小码农的博客*/
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();
    }

}