javafun.txt

在实际JAVA开发中一些常用工具！包扩各种JAVA格式化输出和字符串处理。对初学者有用！

package lightningboard.util;

import java.util.*;

import java.io.PrintStream; 
import java.io.PrintWriter; 
import java.io.OutputStreamWriter; 
import java.text.DecimalFormat; 
import java.text.NumberFormat; 

public class StringUtil
{

    private static final String EOL = System.getProperty("line.separator"); 
    private static PrintWriter handle = new PrintWriter(new OutputStreamWriter(System.out)); 
    public static char fillChar = ' '; 
    private static char alignment; 
    private static boolean separator; 
    private static char base; 
    private static boolean scientific; 
    private static boolean zeroFill; 
    private static int width; 
    private static int decimals; 
    private static String pattern;  

    /************************************************************* 
     Formats the passed value using the passed format descriptor 
     and returns the result as a string. 
     
     @param value the value to be formatted. 
     @param fd the format descriptor.  
     @return the formatted value as a string. 
    **************************************************************/ 
    public static String format(byte value, String fd) 
    { 
        return formatInteger(value, fd, 8); 
    } 

    /************************************************************* 
     Formats the passed value using the passed format descriptor 
     and returns the result as a string. 
     
     @param value the value to be formatted. 
     @param fd the format descriptor.  
     @return the formatted value as a string. 
    **************************************************************/     
    public static String format(char value, String fd) 
    { 
        return formatInteger(value, fd, 16); 
    } 

    /************************************************************* 
     Formats the passed value using the passed format descriptor 
     and returns the result as a string. 
     
     @param value the value to be formatted. 
     @param fd the format descriptor.  
     @return the formatted value as a string. 
    **************************************************************/     
    public static String format(double value, String fd) 
    { 
        extractAttributes(fd); 
        String s1; 
        if(base == 'B') 
        { 
            s1 = Long.toBinaryString(Double.doubleToLongBits(value)); 
            s1 = repeat(64, '0') + s1; 
            s1 = s1.substring(s1.length() - 64); 
        } else if(base == 'X') 
        { 
            s1 = Long.toHexString(Double.doubleToLongBits(value)); 
            s1 = repeat(16, '0') + s1; 
            s1 = s1.substring(s1.length() - 16); 
        } else 
        { 
            pattern = decimals != -1 ? "." + repeat(decimals, '0') : ".#"; 
            if(scientific) 
                pattern = "0" + pattern + "E0"; 
            else 
                pattern = separator ? "#,##0" + pattern : "0" + pattern; 
            s1 = (new DecimalFormat(pattern)).format(value); 
        } 
        return size(s1); 
    } 

    /************************************************************* 
     Formats the passed value using the passed format descriptor 
     and returns the result as a string. 
     
     @param value the value to be formatted. 
     @param fd the format descriptor.  
     @return the formatted value as a string. 
    **************************************************************/     
    public static String format(float value, String fd) 
    { 
        extractAttributes(fd); 
        String s1; 
        if(base == 'B') 
        { 
            s1 = Integer.toBinaryString(Float.floatToIntBits(value)); 
            s1 = repeat(32, '0') + s1; 
            s1 = s1.substring(s1.length() - 32); 
        } else if(base == 'X') 
        { 
            s1 = Integer.toHexString(Float.floatToIntBits(value)); 
            s1 = repeat(8, '0') + s1; 
            s1 = s1.substring(s1.length() - 8); 
        } else 
        { 
            pattern = decimals != -1 ? "." + repeat(decimals, '0') : ".#"; 
            if(scientific) 
                pattern = "0" + pattern + "E0"; 
            else 
                pattern = separator ? "#,##0" + pattern : "0" + pattern; 
            s1 = (new DecimalFormat(pattern)).format(value); 
        } 
        return size(s1); 
    } 

    /************************************************************* 
     Formats the passed value using the passed format descriptor 
     and returns the result as a string. 
     
     @param value the value to be formatted. 
     @param fd the format descriptor.  
     @return the formatted value as a string. 
    **************************************************************/     
    public static String format(int value, String fd) 
    { 
        return formatInteger(value, fd, 32); 
    } 

    /************************************************************* 
     Formats the passed value using the passed format descriptor 
     and returns the result as a string. 
     
     @param value the value to be formatted. 
     @param fd the format descriptor.  
     @return the formatted value as a string. 
    **************************************************************/     
    public static String format(long value, String fd) 
    { 
        return formatInteger(value, fd, 64); 
    } 
     
    /************************************************************* 
     Formats the passed value using the passed format descriptor 
     and returns the result as a string. 
     
     @param value the value to be formatted. 
     @param fd the format descriptor.  
     @return the formatted value as a string. 
    **************************************************************/     
    public static String format(short value, String fd) 
    { 
        return formatInteger(value, fd, 16); 
    } 
     
    /* Formats the passed value using the passed format descriptor 
     * and returns the result as a string. 
     */ 
    private static String formatInteger(long l, String s, int i) 
    { 
        extractAttributes(s); 
        String s1; 
        if(base == 'B') 
        { 
            s1 = Long.toBinaryString(l); 
            s1 = repeat(64, '0') + s1; 
            s1 = s1.substring(s1.length() - i); 
        } else 
        if(base == 'X') 
        { 
            s1 = Long.toHexString(l); 
            s1 = repeat(16, '0') + s1; 
            s1 = s1.substring(s1.length() - i / 4); 
        } else 
        if(separator) 
        { 
            s1 = (new DecimalFormat("#,###")).format(l); 
        } else 
        { 
            s1 = String.valueOf(l); 
            if(zeroFill) 
                s1 = repeat(width - s1.length(), '0') + s1; 
        } 
        return size(s1); 
    } 

    // Gets information from the passed format descriptor. 
    private static void extractAttributes(String s) 
    { 
        s = s.toUpperCase(); 
        alignment = 'R'; 
        separator = false; 
        base = 'D'; 
        scientific = false; 
        zeroFill = false; 
        width = -1; 
        decimals = -1; 
        int i = s.indexOf(76, 0); 
        if(i > -1) 
        { 
            alignment = 'L'; 
            s = s.substring(0, i) + s.substring(i + 1); 
        } 
        i = s.indexOf(67, 0); 
        if(i > -1) 
        { 
            alignment = 'C'; 
            s = s.substring(0, i) + s.substring(i + 1); 
        } 
        i = s.indexOf(44, 0); 
        if(i > -1) 
        { 
            separator = true; 
            pattern = pattern + ",###"; 
            s = s.substring(0, i) + s.substring(i + 1); 
        } 
        i = s.indexOf(88, 0); 
        if(i > -1) 
        { 
            base = 'X'; 
            s = s.substring(0, i) + s.substring(i + 1); 
        } else 
        { 
            i = s.indexOf(66, 0); 
            if(i > -1) 
            { 
                base = 'B'; 
                s = s.substring(0, i) + s.substring(i + 1); 
            } 
        } 
        i = s.indexOf(83, 0); 
        if(i > -1) 
        { 
            scientific = true; 
            s = s.substring(0, i) + s.substring(i + 1); 
        } 
        i = s.indexOf(90, 0); 
        if(i > -1) 
        { 
            zeroFill = true; 
            s = s.substring(0, i) + s.substring(i + 1); 
        } 
        i = s.indexOf(46, 0); 
        if(i > -1) 
        { 
            decimals = Integer.parseInt(s.substring(i + 1)); 
            s = s.substring(0, i); 
        } 
        if(s.length() > 0) 
            width = Integer.parseInt(s); 
    } 
         
    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptor. No trailing End-Of-Line  
     character is printed. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/     
    public static void print(byte value, String fd) 
    { 
        handle.print(format(value, fd)); 
        handle.flush(); 
    } 

    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptor. No trailing End-Of-Line  
     character is printed. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void print(char value, String fd) 
    { 
        handle.print(format(value, fd)); 
        handle.flush(); 
    } 

    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptor. No trailing End-Of-Line  
     character is printed. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void print(double value, String fd) 
    { 
        handle.print(format(value, fd)); 
        handle.flush(); 
    } 

    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptor. No trailing End-Of-Line  
     character is printed. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void print(float value, String fd) 
    { 
        handle.print(format(value, fd)); 
        handle.flush(); 
    } 

    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptor. No trailing End-Of-Line  
     character is printed. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void print(int value, String fd) 
    { 
        handle.print(format(value, fd)); 
        handle.flush(); 
    } 

    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptor. No trailing End-Of-Line  
     character is printed. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void print(long value, String fd) 
    { 
        handle.print(format(value, fd)); 
        handle.flush(); 
    } 
     
    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptor. No trailing End-Of-Line  
     character is printed. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void print(short value, String fd) 
    { 
        handle.print(format(value, fd)); 
        handle.flush(); 
    } 
     
    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptorand followed by an End-Of-Line  
     marker. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void println(byte value, String fd) 
    { 
        print(value, fd); 
        handle.print(EOL); 
        handle.flush(); 
    } 

    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptorand followed by an End-Of-Line  
     marker. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void println(char value, String fd) 
    { 
        print(value, fd); 
        handle.print(EOL); 
        handle.flush(); 
    } 

    /************************************************************* 
     Output the passed value to the standard output device using 
     the passed format descriptorand followed by an End-Of-Line  
     marker. 
     
     @param value the value to be printed. 
     @param fd the format descriptor.  
    **************************************************************/      
    public static void println(double value, String fd) 
    { 
        print(value, fd); 
        handle.print(EOL); 
        handle.flush(); 
    }