Java String工具类StringHelper详解编程语言

主要功能是字符串与InputStream、byte数组的转换，判断手机号，判断中文、判断邮箱、判断邮编、四舍五入、取几位小数等。

代码如下：

import java.io.BufferedReader; 
import java.io.ByteArrayInputStream; 
import java.io.ByteArrayOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.io.StringWriter; 
import java.math.BigDecimal; 
import java.util.regex.Matcher; 
import java.util.regex.Pattern; 
import android.text.TextUtils; 
public class StringHelper { 
private static StringHelper util; 
public final String[] PHONE_PREFIX = new String[] { "130", "131", "132", 
"133", "134", "135", "136", "137", "138", "139", "150", "151", 
"152", "153", "154", "155", "156", "157", "158", "159", "180", 
"181", "182", "183", "184", "185", "186", "187", "188", "189" }; 
public static StringHelper getInstance() { 
if (util == null) { 
util = new StringHelper(); 
} 
return util; 
} 
private StringHelper() { 
super(); 
} 
/** 
* InputStream转byte数组 
*  
* @param is 
* @return 
*/ 
public byte[] stream2Byte(InputStream is) { 
byte[] in_b = null; 
try { 
ByteArrayOutputStream os = new ByteArrayOutputStream(); 
int i = -1; 
while ((i = is.read()) != -1) { 
os.write(i); 
} 
in_b = os.toByteArray(); 
} catch (IOException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
return in_b; 
} 
/** 
* InputStream 转String 
*  
* @param is 
* @return 
*/ 
public String stream2String(InputStream is) { 
try { 
BufferedReader br = new BufferedReader(new InputStreamReader(is)); 
StringWriter sw = new StringWriter(); 
int i = -1; 
while ((i = br.read()) != -1) { 
sw.write(i); 
} 
return sw.getBuffer().toString(); 
} catch (Exception e) { 
// TODO: handle exception 
} 
return null; 
} 
/** 
* 字符串转InputStream 
*  
* @param str 
* @return 
*/ 
public InputStream string2Stream(String str) { 
ByteArrayInputStream is = new ByteArrayInputStream(str.getBytes()); 
return is; 
} 
/** 
* byte数组转InputStream 
*  
* @param by 
* @return 
*/ 
public InputStream byte2Stream(byte[] by) { 
ByteArrayInputStream stream = new ByteArrayInputStream(by); 
return stream; 
} 
/** 
* 判断是否是中文字符,只能判断部分CJK字符 
*  
* @param str 
* @return 
*/ 
public boolean isChina(String str) { 
Pattern p = Pattern.compile("[//u4E00-//u9FBF]+"); 
Matcher m = p.matcher(str); 
return m.matches(); 
} 
/** 
* 根据Unicode编码完美的判断中文汉字和符号 
*  
* @param c 
* @return 
*/ 
private boolean isChinese(char c) { 
Character.UnicodeBlock ub = Character.UnicodeBlock.of(c); 
if (ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS 
|| ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS 
|| ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A 
|| ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B 
|| ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION 
|| ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS 
|| ub == Character.UnicodeBlock.GENERAL_PUNCTUATION) { 
return true; 
} 
return false; 
} 
/** 
* 判断是否包含中文汉字 
*  
* @param strName 
* @return 
*/ 
public boolean isChineseHave(String strName) { 
char[] ch = strName.toCharArray(); 
for (int i = 0; i < ch.length; i++) { 
char c = ch[i]; 
if (isChinese(c)) { 
return true; 
} 
} 
return false; 
} 
/** 
* 判断是否只有中文汉字 
*  
* @param strName 
* @return 
*/ 
public boolean isChineseAll(String strName) { 
char[] ch = strName.toCharArray(); 
for (int i = 0; i < ch.length; i++) { 
char c = ch[i]; 
if (!isChinese(c)) { 
return false; 
} 
} 
return true; 
} 
/** 
* 判断邮政编码 
*  
* @param str 
* @return 
*/ 
public boolean isCard(String str) { 
Pattern p = Pattern.compile("[1-9]//d{5}(?!//d)"); 
Matcher m = p.matcher(str); 
return m.matches(); 
} 
/** 
* 检测邮箱合法性 
*  
* @param email 
* @return 
*/ 
public boolean isEmail(String email) { 
if ((email == null) || (email.trim().length() == 0)) { 
return false; 
} 
String regEx = "^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+//.[a-zA-Z]{2,4}$"; 
Pattern p = Pattern.compile(regEx); 
Matcher m = p.matcher(email.trim().toLowerCase()); 
return m.find(); 
} 
/** 
* 检查手机号码合法性 
*  
* @param mdn 
* @return 
*/ 
public boolean isPhoneNumber(String mdn, boolean checkLen) { 
if (mdn == null || mdn.equals("")) { 
return false; 
} 
if (mdn.startsWith("+86")) { 
mdn = mdn.substring(3); 
} 
if (checkLen && mdn.length() != 11) { 
return false; 
} 
boolean flag = false; 
String p = mdn.length() > 3 ? mdn.substring(0, 3) : mdn; 
for (int i = 0; i < PHONE_PREFIX.length; i++) { 
if (p.equals(PHONE_PREFIX[i])) { 
flag = true; 
break; 
} 
} 
if (!flag) { 
return false; 
} 
return true; 
} 
/** 
* 判断字符串中是否是整型数字 
*  
* @param str 
* @return 
*/ 
public boolean isInt(String str) { 
if (!TextUtils.isEmpty(str)) { 
return str.toString().matches("^[-]?//d+$"); 
} 
return false; 
} 
/** 
* 字符串转整型 
*  
* @param str 
* @return 
*/ 
public int getInt(String str) { 
if (!TextUtils.isEmpty(str)) { 
String newValue = str.toString().replaceAll("//D+", ""); 
if (!TextUtils.isEmpty(newValue)) { 
return 0; 
} 
return Integer.parseInt(newValue); 
} 
return 0; 
} 
/** 
* 判断字符串中是否是Double 
*  
* @param str 
* @return 
*/ 
public boolean isDouble(String str) { 
if (!TextUtils.isEmpty(str)) { 
return str.toString().matches("^//d+(//.[//d]+)?$"); 
} 
return false; 
} 
/** 
* 字符串转Double 
*  
* @param str 
* @return 
*/ 
public double getDouble(String str) { 
if (!TextUtils.isEmpty(str)) { 
if (isDouble(str)) 
return Double.parseDouble(str); 
else 
return 0.0D; 
} 
return 0.0D; 
} 
/** 
* 字符串转Double,并进行四舍五入 
*  
* @param v 
* @param scale 
* @return 
*/ 
public double getDouble(String str, int scale) { 
Double v = getDouble(str); 
return getDouble(v, scale); 
} 
/** 
* Double进行四舍五入 
*  
* @param v 
* @param scale 
* @return 
*/ 
public double getDouble(Double v, int scale) { 
if (scale < 0) { 
scale = 0; 
} 
BigDecimal b = new BigDecimal(v); 
BigDecimal one = new BigDecimal("1"); 
return b.divide(one, scale, BigDecimal.ROUND_HALF_UP).doubleValue(); 
} 
/** 
* 得到指定位数的小数 
* @param v 
* @param scale 
* @return 
*/ 
public String getDecimals(Double v, int scale) { 
return String.format("%." + String.valueOf(scale) + "f", v); 
} 
/** 
* 得到指定位数的小数 
* @param v 
* @param scale 
* @return 
*/ 
public String getDecimals(String v, int scale) { 
return getDecimals(getDouble(v), scale); 
} 
}