FormatUtil.java

/*
 * Copyright 1999-2012 Alibaba Group.
 *  
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.alibaba.cobar.util;

/**
 * 格式化工具
 * 
 * @author xianmao.hexm
 * @version 2008-11-24 下午12:58:17
 */
public final class FormatUtil {

    // 右对齐格式化字符串
    public static final int ALIGN_RIGHT = 0;

    // 左对齐格式化字符串
    public static final int ALIGN_LEFT = 1;

    private static final char defaultSplitChar = ' ';

    private static final String[] timeFormat = new String[] { "d ", "h ", "m ", "s ", "ms" };

    /**
     * 格式化后返回的字符串
     * 
     * @param s 需要格式化的原始字符串，默认按左对齐。
     * @param fillLength 填充长度
     * @return String
     */
    public static String format(String s, int fillLength) {
        return format(s, fillLength, defaultSplitChar, ALIGN_LEFT);
    }

    /**
     * 格式化后返回的字符串
     * 
     * @param i 需要格式化的数字类型，默认按右对齐。
     * @param fillLength 填充长度
     * @return String
     */
    public static String format(int i, int fillLength) {
        return format(Integer.toString(i), fillLength, defaultSplitChar, ALIGN_RIGHT);
    }

    /**
     * 格式化后返回的字符串
     * 
     * @param l 需要格式化的数字类型，默认按右对齐。
     * @param fillLength 填充长度
     * @return String
     */
    public static String format(long l, int fillLength) {
        return format(Long.toString(l), fillLength, defaultSplitChar, ALIGN_RIGHT);
    }

    /**
     * @param s 需要格式化的原始字符串
     * @param fillLength 填充长度
     * @param fillChar 填充的字符
     * @param align 填充方式（左边填充还是右边填充）
     * @return String
     */
    public static String format(String s, int fillLength, char fillChar, int align) {
        if (s == null) {
            s = "";
        } else {
            s = s.trim();
        }
        int charLen = fillLength - s.length();
        if (charLen > 0) {
            char[] fills = new char[charLen];
            for (int i = 0; i < charLen; i++) {
                fills[i] = fillChar;
            }
            StringBuilder str = new StringBuilder(s);
            switch (align) {
            case ALIGN_RIGHT:
                str.insert(0, fills);
                break;
            case ALIGN_LEFT:
                str.append(fills);
                break;
            default:
                str.append(fills);
            }
            return str.toString();
        } else {
            return s;
        }
    }

    /**
     * 格式化时间输出
     * <p>
     * 1d 15h 4m 15s 987ms
     * </p>
     */
    public static String formatTime(long millis, int precision) {
        long[] la = new long[5];
        la[0] = (millis / 86400000);// days
        la[1] = (millis / 3600000) % 24;// hours
        la[2] = (millis / 60000) % 60;// minutes
        la[3] = (millis / 1000) % 60;// seconds
        la[4] = (millis % 1000);// ms

        int index = 0;
        for (int i = 0; i < la.length; i++) {
            if (la[i] != 0) {
                index = i;
                break;
            }
        }

        StringBuilder buf = new StringBuilder();
        int validLength = la.length - index;
        for (int i = 0; (i < validLength && i < precision); i++) {
            buf.append(la[index]).append(timeFormat[index]);
            index++;
        }
        return buf.toString();
    }

}