org.apache.commons.lang3功能演示

代碼

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("計算字符串中包含某字符數.");  
        System.out.println(CharSetUtils.count(  
                "The quick brown fox jumps over the lazy dog.", "aeiou"));  

        System.out.println("刪除字符串中某字符.");  
        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("合併重複的字符.");  
        System.out.println(CharSetUtils.squeeze("a  bbbbbb     c dd", "b d"));  
    }  

    public void objectUtilsDemo()  
    {  
        System.out.println("**ObjectUtilsDemo**");  
        System.out.println("Object爲null時，默認打印某字符.");  
        Object obj = null;  
        System.out.println(ObjectUtils.defaultIfNull(obj, "空"));  

        System.out.println("驗證兩個引用是否指向的Object是否相等,取決於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("用父類Object的toString()方法返回對象信息.");  
        Date date = new Date();  
        System.out.println(ObjectUtils.identityToString(date));  
        System.out.println(date);  

        System.out.println("返回類本身的toString()方法結果,對象爲null時，返回0長度字符串.");  
        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("生成指定長度的隨機字符串,好像沒什麼用.");  
        System.out.println(RandomStringUtils.random(500));  

        System.out.println("在指定字符串中生成長度爲n的隨機字符串.");  
        System.out.println(RandomStringUtils.random(5, "abcdefghijk"));  

        System.out.println("指定從字符或數字中生成隨機字符串.");  
        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("將字符串重複n次，將文字按某寬度居中，將字符串數組用某字符串連接.");  
        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("縮短到某長度,用...結尾.");  
        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("返回兩字符串不同處索引號.");  
        System.out.println(StringUtils.indexOfDifference("aaabc", "aaacc"));  

        System.out.println("返回兩字符串不同處開始至結束.");  
        System.out.println(StringUtils.difference("aaabcde", "aaaccde"));  

        System.out.println("截去字符串爲以指定字符串結尾的部分.");  
        System.out.println(StringUtils.chomp("aaabcde", "de"));  

        System.out.println("檢查一字符串是否爲另一字符串的子集.");  
        System.out.println(StringUtils.containsOnly("aad", "aadd"));  

        System.out.println("檢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("檢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("返回可以處理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("判斷是否是某類字符.");  
        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("獲得系統文件分隔符.");  
        System.out.println(SystemUtils.FILE_SEPARATOR);  

        System.out.println("獲得源文件編碼.");  
        System.out.println(SystemUtils.FILE_ENCODING);  

        System.out.println("獲得ext目錄.");  
        System.out.println(SystemUtils.JAVA_EXT_DIRS);  

        System.out.println("獲得java版本.");  
        System.out.println(SystemUtils.JAVA_VM_VERSION);  

        System.out.println("獲得java廠商.");  
        System.out.println(SystemUtils.JAVA_VENDOR);  
    }  

    public void classUtilsDemo()  
    {  
        System.out.println(genHeader("ClassUtilsDemo"));  
        System.out.println("獲取類實現的所有接口.");  
        System.out.println(ClassUtils.getAllInterfaces(Date.class));  

        System.out.println("獲取類所有父類.");  
        System.out.println(ClassUtils.getAllSuperclasses(Date.class));  

        System.out.println("獲取簡單類名.");  
        System.out.println(ClassUtils.getShortClassName(Date.class));  

        System.out.println("獲取包名.");  
        System.out.println(ClassUtils.getPackageName(Date.class));  

        System.out.println("判斷是否可以轉型.");  
        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("轉換特殊字符.");  
        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("字符串轉爲數字(不知道有什麼用).");  
        System.out.println(NumberUtils.toInt("ba", 33));  

        System.out.println("從數組中選出最大值.");  
        System.out.println(NumberUtils.max(new int[] { 1, 2, 3, 4 }));  

        System.out.println("判斷字符串是否全是整數.");  
        System.out.println(NumberUtils.isDigits("123.1"));  

        System.out.println("判斷字符串是否是有效數字.");  
        System.out.println(NumberUtils.isNumber("0123.1"));  
    }  

    public void dateFormatUtilsDemo()  
    {  
        System.out.println(genHeader("DateFormatUtilsDemo"));  
        System.out.println("格式化日期輸出.");  
        System.out.println(DateFormatUtils.format(System.currentTimeMillis(),  
                "yyyy-MM-dd HH:mm:ss"));  

        System.out.println("秒錶.");  
        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("秒錶計時:" + 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();  

    }  

}