【工具类】字符串处理工具类

去开头的“/”与结尾的“？1234”
应用大小的转换类
转换进度成百分比形式
去除path中开头的“/”
星级转换方法

import java.text.DecimalFormat;

public class StringUtil {
    /**
     * 
    * @Title: getAppPath
    * @Description: TODO   “/web/webdsfs/sfwe12re.apk?12324”--- 去开头的“/”与结尾的“？1234”
    * @param str
    * @return
     */
    public static String getAppPath(String str) {
        if(str == null){
            return null;
        }
        if (!str.contains("?") && !str.startsWith("/")) {
            return str;
        }
        int starPosition = 0;
        int endPosition;
        if (str.startsWith("/")) {
            starPosition = 1;
        }
        if (str.contains("?")) {
            endPosition = str.indexOf("?");
        } else {
            endPosition = str.length();
        }
        endPosition = str.length();
        return str.substring(starPosition, endPosition);
    }

    /**
     * 
     * @Title: getDataSize
     * @Description: TODO 每个Item中的应用大小的转换类
     * @param size
     * @return
     */
    public static String getDataSize(String sSize) {
        if (sSize == null || "".equals(sSize)) {
            return " 0 M";
        }
        long size = Long.parseLong(sSize);
        if (size < 0) {
            size = 0;
        }
        DecimalFormat formater = new DecimalFormat("####.00");
        if (size < 1024) {
            return size + "bytes";
        } else if (size < 1024 * 1024) {
            float kbsize = size / 1024f;
            return formater.format(kbsize) + "KB";
        } else if (size < 1024 * 1024 * 1024) {
            float mbsize = size / 1024f / 1024f;
            return formater.format(mbsize) + "MB";
        } else if (size < 1024 * 1024 * 1024 * 1024) {
            float gbsize = size / 1024f / 1024f / 1024f;
            return formater.format(gbsize) + "GB";
        } else {
            return " 0 M";
        }
    }

    /**
     * 
     * @Title: getProgress
     * @Description: TODO 转换进度成百分比形式
     * @param current
     *            当前下载大小
     * @param total
     *            当大小
     * @return
     */
    public static String getProgress(int current, int total) {
        if (total == 0) {
            return 0 + "%";
        }
        DecimalFormat formater = new DecimalFormat("##0.0");
        float kbsize = (float) (current) / (float) total * 100;
        if(kbsize > 100f){
            kbsize = 100f; 
        }
        return formater.format(kbsize) + "%";
    }

    /**
     * 
     * @Title: removeSpace
     * @Description: TODO 去除path中开头的“/”
     * @return
     */
    public static String removeSpace(String path) {
        if (!path.startsWith("/")) {
            return path;
        }
        String address = path.substring(1, path.length());
        return address;
    }

    /**
     * 星级转换方法
     * @param star_level
     * @return
     */
    public static String getStar_level(String star_level) {
        if (star_level == null) {
            return "0.0";
        }
        float star_num = Float.parseFloat(star_level);
        DecimalFormat formater = new DecimalFormat("#0.0");
        return formater.format(star_num);
    }
}