常用工具类
import java.io.ByteArrayOutputStream; import java.io.File; import java.io.FileWriter; import java.io.IOException; import java.io.InputStream; import java.math.BigDecimal; import java.util.Collection; import java.util.Map; import java.util.Random; import com.google.common.base.Strings; import com.nonobank.common.base.RandomNumbers; /** * 常用工具类 * @author changbingbing * */ public class Utils { final static int BUFFER_SIZE = 4096; private final static String[] RANDOM_CODE = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d", "", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z" };
生成8位随机整数
/** * * @Title: get8Random * @Description:生成8位随机整数 * @return * @Return: String * */ private static String get8Random() { String arr[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9" }; String myRandom = ""; for (int i = 0; i < 8; i++) { int lotteryNumber = new Random().nextInt(10); myRandom = myRandom + arr[lotteryNumber]; } return myRandom; }
屏蔽身份证
/** * 屏蔽身份证 * * @param idnum * @return */ public static String hideIdnum(String idnum) { if (Strings.isNullOrEmpty(idnum)) return ""; if (idnum.length() == 18) return idnum.substring(0, 6) + "********" + idnum.substring(14); else if (idnum.length() == 15) return idnum.substring(0, 6) + "********" + idnum.substring(12); return ""; }
将生成的html协议文件输出到指定的文件
/** * 将生成的html协议文件输出到指定的文件 * * @param content * @param path * @param fileName * @throws IOException */ public static void writeToFile(String content, String path, String fileName) throws IOException { String head = "<html>" + "<head>" + "<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />" + "</head>"; String tail = "</body></html>"; try (FileWriter fw = new FileWriter(path + File.separator + fileName)) { fw.write(head); fw.write(content); fw.write(tail); } }
判断对象或对象数组中每一个对象是否为空 对象为null，字符序列长度为0，集合类、Map为empty
/** * * @Title: isNull * @Description:判断对象或对象数组中每一个对象是否为� 对象为null，字符序列长度为0，集合类、Map为empty * @param obj * @return * @throws IOException * @Return: boolean * */ public static boolean isNullOrEmpty(Object obj) { if (obj == null) return true; if (obj instanceof CharSequence) return ((CharSequence) obj).length() == 0; if (obj instanceof Collection) return ((Collection) obj).isEmpty(); if (obj instanceof Map) return ((Map) obj).isEmpty(); if (obj instanceof Object[]) { Object[] object = (Object[]) obj; if (object.length == 0) { return true; } boolean empty = true; for (int i = 0; i < object.length; i++) { if (!isNullOrEmpty(object[i])) { empty = false; break; } } return empty; } return false; }
2个double相除，并传入精度，得出结论
/** * * @Title: div * @Description:2个double相除，并传入精度，得出结论 * @param d1 * @param d2 * @param len * @return * @Return: double * */ public static double div(double d1, double d2, int len) {// 进行除法运算 BigDecimal b1 = new BigDecimal(d1); BigDecimal b2 = new BigDecimal(d2); return b1.divide(b2, len, BigDecimal.ROUND_HALF_UP).doubleValue(); }
保留2位有效数字，四舍五入
/** * 保留2位有效数字，四舍五入 * @param amount * @return */ public static BigDecimal Scale(BigDecimal amount){ return amount.setScale(2, BigDecimal.ROUND_HALF_UP); }
将InputStream转换成某种字符编码的String
/** * 将InputStream转换成某种字符编码的String * * @param in * @param encoding * @return * @throws Exception */ public static String InputStreamTOString(InputStream in, String encoding) throws Exception { ByteArrayOutputStream outStream = new ByteArrayOutputStream(); byte[] data = new byte[BUFFER_SIZE]; int count = -1; while ((count = in.read(data, 0, BUFFER_SIZE)) != -1) outStream.write(data, 0, count); data = null; return new String(outStream.toByteArray(), encoding); }
生成N位随机数
/** * 生成N位随机数� * * @param length * 随机长度 * @return */ public static String generateRandomNum(int length) { Integer verifyNumInt = RandomNumbers.randomInt(length); return verifyNumInt.toString(); }