java實(shí)現(xiàn)字符串和數(shù)字轉(zhuǎn)換工具

package com.test.util;

/**
 * 數(shù)字工具類
 */
public class NumberUtil {

 /**
  * 數(shù)字轉(zhuǎn)換為字符串
  * @param num 數(shù)字
  * @return 字符串,如果 num 為空, 返回空字符串
  */
 public static String num2Str(Object num) {
  String str = null;

  if (num == null) {
   str = "";
  }
  else {
   str = String.valueOf(num);
  }
  return str;
 }

 /**
  * 字符串轉(zhuǎn)換為Integer
  * @param str 字符串
  * @return Integer, str為null時(shí)返回0
  */
 public static Integer getInteger(Object obj) {
  return getInteger(obj, 0);
 }

 /**
  * 字符串轉(zhuǎn)換為Integer
  * @param str 字符串
  * @param def 默認(rèn)值
  * @return Integer, 字符串為null時(shí)返回def
  */
 public static Integer getInteger(Object obj, int def) {
  String str = obj == null ? "" : obj.toString();

  Integer i = null;

  if (str.trim().length() == 0) {
   i = new Integer(def);
  }
  else {
   try {
    i = Integer.valueOf(str);
   }
   catch (Exception e) {
   }
  }

  return i == null ? new Integer(def) : i;
 }

 /**
  * 字符串轉(zhuǎn)換為Long
  * @param str 字符串
  * @return Long, str為null時(shí)返回0
  */
 public static Long getLong(Object obj) {
  return getLong(obj, 0);
 }

 /**
  * 字符串轉(zhuǎn)換為Long
  * @param str 字符串
  * @param def 默認(rèn)值
  * @return Long, 字符串為null時(shí)返回def
  */
 public static Long getLong(Object obj, long def) {
  String str = obj == null ? "" : obj.toString();

  Long l = null;

  if (str.trim().length() == 0) {
   l = new Long(def);
  }
  else {
   try {
    l = Long.valueOf(str);
   }
   catch (Exception e) {
   }
  }

  return l == null ? new Long(def) : l;
 }

 /**
  * 字符串轉(zhuǎn)換為Integer
  * @param str 字符串
  * @return Integer, str為null時(shí)返回0
  */
 public static int getIntegerValue(Object obj) {
  return getIntegerValue(obj, 0);
 }

 /**
  * 字符串轉(zhuǎn)換為Integer
  * @param str 字符串
  * @param def 默認(rèn)值
  * @return Integer, 字符串為null時(shí)返回def
  */
 public static int getIntegerValue(Object obj, int def) {
  return getInteger(obj, def).intValue();
 }

 /**
  * 字符串轉(zhuǎn)換為Long
  * @param str 字符串
  * @return Long, str為null時(shí)返回0
  */
 public static long getLongValue(Object obj) {
  return getLongValue(obj, 0);
 }

 /**
  * 字符串轉(zhuǎn)換為Long
  * @param str 字符串
  * @param def 默認(rèn)值
  * @return Long, 字符串為null時(shí)返回def
  */
 public static long getLongValue(Object obj, long def) {
  return getLong(obj, def).longValue();
 }
}