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);
}
}
原创文章，作者：Maggie-Hunter，如若转载，请注明出处：https://blog.ytso.com/tech/pnotes/10739.html