java implements string and number conversion tools

This article example for everyone to share the java string and digital conversion tools specific code, for your reference, the specific content is as follows

package com.test.util;

/**
 *  Digital tool class 
 */
public class NumberUtil {

 /**
  *  Convert numbers to strings 
  * @param num  Figures 
  * @return  String , If  num  Empty ,  Returns an empty string 
  */
 public static String num2Str(Object num) {
  String str = null;

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

 /**
  *  String is converted to Integer
  * @param str  String 
  * @return Integer, str For null Return when 0
  */
 public static Integer getInteger(Object obj) {
  return getInteger(obj, 0);
 }

 /**
  *  String is converted to Integer
  * @param str  String 
  * @param def  Default value 
  * @return Integer,  The string is null Return when 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;
 }

 /**
  *  String is converted to Long
  * @param str  String 
  * @return Long, str For null Return when 0
  */
 public static Long getLong(Object obj) {
  return getLong(obj, 0);
 }

 /**
  *  String is converted to Long
  * @param str  String 
  * @param def  Default value 
  * @return Long,  The string is null Return when 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;
 }

 /**
  *  String is converted to Integer
  * @param str  String 
  * @return Integer, str For null Return when 0
  */
 public static int getIntegerValue(Object obj) {
  return getIntegerValue(obj, 0);
 }

 /**
  *  String is converted to Integer
  * @param str  String 
  * @param def  Default value 
  * @return Integer,  The string is null Return when def
  */
 public static int getIntegerValue(Object obj, int def) {
  return getInteger(obj, def).intValue();
 }

 /**
  *  String is converted to Long
  * @param str  String 
  * @return Long, str For null Return when 0
  */
 public static long getLongValue(Object obj) {
  return getLongValue(obj, 0);
 }

 /**
  *  String is converted to Long
  * @param str  String 
  * @param def  Default value 
  * @return Long,  The string is null Return when def
  */
 public static long getLongValue(Object obj, long def) {
  return getLong(obj, def).longValue();
 }
}