str.java

文件的上传和下载的实现,用JAva编写,非常简单

/**
 * Time: 2005-06-28 ModifyTime: 2005-07-03
 * 
 * Company: 武汉理工大学计算机学院
 * 
 * @version 1.0
 * @author: 彭法銮 Email: [e-mail] QQ: 8330108
 */
package edu.whut.cwts.pg.db;


//import java.util.StringTokenizer;
import java.util.regex.*;
import java.io.*;

public final class Str {

    /**
     * 判断String是否为null
     */
    public static boolean isNull(String str) {
        if (str == null || str.trim().equals("") || str.trim().equals("null"))
            return true;
        else
            return false;
    }

    public static boolean isNull(int str) {
        if (new Integer(str) == null)
            return true;
        else
            return false;
    }

    public static boolean isNull(float str) {
        if (new Float(str) == null)
            return true;
        else
            return false;
    }

    /**
     * 将String为null换成""
     */
    public static String doNull(String str) {
        if (Str.isNull(str))
            str = "";
        return str;
    }

    /**
     * 将int为null换成0
     */
    public static int doNull(int str) {
        if (Str.isNull(str))
            str = 0;
        return str;
    }

    /**
     * 将float为null换成0.0
     */
    public static float doNull(float str) {
        if (Str.isNull(str))
            str = 0.0f;
        return str;
    }

    /**
     * 转换中文
     */
    public static String getStr(String str) {
        str = Str.doNull(str);
        try {
            byte[] temp_t = str.getBytes("ISO8859-1");
            String temp = new String(temp_t);
            return temp;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return "null";

    }

    /**
     * 将字符串src中的子字符串fnd全部替换为新子字符串rep. <br>
     * 功能相当于java sdk 1.4的String.replaceAll方法. <br>
     * 不同之处在于查找时不是使用正则表达式而是普通字符串.
     */
    public static String replaceAll(String src, String fnd, String rep)
            throws Exception {
        if (src == null || src.equals("")) {
            return "";
        }

        String dst = src;

        int idx = dst.indexOf(fnd);

        while (idx >= 0) {
            dst = dst.substring(0, idx) + rep
                    + dst.substring(idx + fnd.length(), dst.length());
            idx = dst.indexOf(fnd, idx + rep.length());
        }

        return dst;
    }

    /**
     * 将String转换成金额，先对非空进行判断， 0.0的数值将返回""; int len是小数点后位数
     */
    public static String doMoney(String str, int len) {
        String str1 = Str.doNull(str);
        if (Str.isNull(str1)) {
            return "";
        }
        int indexOfPoint = str1.indexOf(".");
        if (indexOfPoint < 0) {
            return str1;
        }

        int last = indexOfPoint + len >= str1.length() ? str1.length()
                : indexOfPoint + len + 1;
        return str1.substring(0, last);
    }

    public static String doMoney(String str) {
        return doMoney(str, 2);
    }

    /**
     * 此方法可以将TextArea中的空格、回车识别出来， 空格用&nbsp代替，回车用 <br>
     * 代替
     */
    public static String returnToBr(String sStr) {

        if (sStr == null || sStr.equals("")) {
            return sStr;
        }

        StringBuffer sTmp = new StringBuffer();
        int i = 0;
        while (i <= sStr.length() - 1) {
            if (sStr.charAt(i) == '\n'/* ||sStr.charAt(i)=='\r' */) {
                sTmp = sTmp.append("<br>");
            } else if (sStr.charAt(i) == ' ') {
                sTmp = sTmp.append("&nbsp;");
            } else {
                sTmp = sTmp.append(sStr.substring(i, i + 1));
            }
            i++;
        }
        String S1;
        S1 = sTmp.toString();
        return S1;
    }

    /**
     * 此方法和上面的returnToBr()方法相反，此是将String中的 <br>
     * 去除
     */
    public static String returnToBrVerse(String sStr) {

        if (sStr == null || sStr.equals("")) {
            return sStr;
        }

        StringBuffer sTmp = new StringBuffer();
        int i = 0;
        while (i <= sStr.length() - 1) {

            int flag = 0;

            if (sStr.charAt(i) == '<') {
                flag = 1;
            }
            if ((sStr.charAt(i + 1) == 'b') && flag == 1) {
                flag = 2;
            }
            if ((sStr.charAt(i + 1) == 'r') && flag == 2) {
                flag = 3;
            }
            if ((sStr.charAt(i + 1) == '>') && flag == 3) {
                flag = 4;
            }

            if (flag == 4) {
                sTmp = sTmp.append("");
            } else {
                sTmp = sTmp.append(sStr.substring(i, i + 1));
            }

            i++;
            flag = 0;
        }
        String S1;
        S1 = sTmp.toString();
        return S1;

    }

    /**
     * 将金钱的数字变成大写的
     */
    public static String fmtNumBig(int num, boolean enter) {
        String strNum = num + "";
        int length = strNum.length();
        if (length > 5)
            return "";
        StringBuffer result = new StringBuffer();
        String[] a = { "億", "仟萬", "佰萬", "拾萬", "萬", "仟", "佰", "拾" };
        for (int i = 0; i < length; i++) {
            switch (strNum.charAt(i)) {
            case '1':
                result.append("壹");
                break;
            case '2':
                result.append("贰");
                break;
            case '3':
                result.append("叁");
                break;
            case '4':
                result.append("肆");
                break;
            case '5':
                result.append("伍");
                break;
            case '6':
                result.append("陆");
                break;
            case '7':
                result.append("七");
                break;
            case '8':
                result.append("八");
                break;
            case '9':
                result.append("九");
                break;
            case '0':
                result.append("零");
                break;
            default:
                break;
            }
        }
        StringBuffer b = new StringBuffer();
        for (int i = 0; i < length; i++) {
            String temp = result.substring(i, i + 1);
            if (temp.equals("零")) {
                if (i != length - 1)
                    b.append(temp);
            } else {
                b.append(temp);
                if (i < length - 1)
                    b.append(a[a.length - length + i + 1]);
            }
        }
        while (b.substring(b.length() - 1, b.length()).equals("零")) {
            b.delete(b.length() - 1, b.length());
        }

        for (int i = 0; i < length - 1; i++) {
            if (b.substring(i, i + 1).equals("零")) {
                while (b.substring(i + 1, i + 2).equals("零")) {
                    b.delete(i + 1, i + 2);
                    length--;
                }
            }

        }
        if (!enter)
            return b.toString();
        length = b.length();
        StringBuffer c = new StringBuffer();
        for (int i = 0; i < length; i++) {
            c.append(b.substring(i, i + 1)).append("<br>");
        }

        return c.toString();
    }

    /**
     * 取得文件名的后缀
     */
    public static String getExt(String filename) {
        String result = "";
        if (filename.lastIndexOf(".") == -1) {
            return result;
        }
        return filename.substring(filename.lastIndexOf(".") + 1, filename
                .length());
    }

    /**
     * 取文件的名称,不含后缀
     */
    public static String getFileName(String fileName) {
        if (fileName.lastIndexOf(".") == -1) {
            return fileName;
        }
        return fileName.substring(0, fileName.lastIndexOf("."));
    }

    /**
     * 判断此后缀是否是图片,如果是图片返回true， 否则返回flase
     */
    public static boolean isPhoto(String fileName) {
        //得到文件的后缀名
        String fileExtName = getExt(fileName);

        if (fileExtName.equals("jpg")) {
            return true;
        } else if (fileExtName.equals("jpeg")) {
            return true;
        } else if (fileExtName.equals("gif")) {
            return true;
        } else if (fileExtName.equals("bmp")) {
            return true;