char target
public char charAt(int arg0) {
return target
}
public int length() {
if (target == '\u0000') {
return 0
}
return 1
}
public CharSequence subSequence(int arg0, int arg1) {
return null
}
public MyCharacter(char c) {
this.target = c
}
}
Pattern.matches("[a-zA-Z]", new MyCharacter('a'))
判断代码如下，可参照：
public class K1 {public static void main(String[] args) {
Pattern p = Pattern.compile("[a-zA-z]")
if(p.matcher("哈哈哈哈x哈哈").find())
{
}else{
System.out.println("不含英文字符")
}
}
}
下满给出示例代码，希望对你有帮助Java中判断字符串的编码有两种思路：
一种是根据byte的长度判断，英文的字母数字好标点符号都是一个byte，且值在0-255之间
另一种是根据中文的Unicode取值范围判断，这个就是把所以的范围都包含，才能判断正确，参考unicode中文范围：
示例代码：
import java.util.regex.Matcher
import java.util.regex.Pattern
public class StringTest {
//英文占1byte，非英文（可认为是中文）占2byte，根据这个特性来判断字符
public static boolean checkChar(char ch) {
if ((ch + "").getBytes().length == 1) {
return true//英文
} else {
return false//中文
}
}
public static String checkString(String str) {
String res = ""
if (str != null) {
for (int i = 0 i < str.length() i++) {
//只要字符串中有中文则为中文
if (!checkChar(str.charAt(i))) {
res = "中文"
break
} else {
res = "英文"
}
}
}
return res
}
//判断是不是中文
public static 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.GENERAL_PUNCTUATION
|| ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION
|| ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS) {
return true
}
return false
}
//判断是不是英文字母
public static boolean isEnglish(String charaString) {
return charaString.matches("^[a-zA-Z]*")
}
//根据中文unicode范围判断u4e00 ~ u9fa5不全
public static String isChinese(String str) {
String regEx1 = "[\\u4e00-\\u9fa5]+"
String regEx2 = "[\\uFF00-\\uFFEF]+"
String regEx3 = "[\\u2E80-\\u2EFF]+"
String regEx4 = "[\\u3000-\\u303F]+"
String regEx5 = "[\\u31C0-\\u31EF]+"
Pattern p1 = Pattern.compile(regEx1)
Pattern p2 = Pattern.compile(regEx2)
Pattern p3 = Pattern.compile(regEx3)
Pattern p4 = Pattern.compile(regEx4)
Pattern p5 = Pattern.compile(regEx5)
Matcher m1 = p1.matcher(str)
Matcher m2 = p2.matcher(str)
Matcher m3 = p3.matcher(str)
Matcher m4 = p4.matcher(str)
Matcher m5 = p5.matcher(str)
if (m1.find() || m2.find() || m3.find() || m4.find() || m5.find())
return "中文"
else
return "英文"
}
public static void main(String[] args) {
System.out.println("使用长度判断:")
System.out.println(checkString("Hello++"))
System.out.println(checkString("Hello++。、，？"))
System.out.println(checkString("Hello++编程"))
System.out.println(checkString("编程"))
System.out.println("\r\n使用正则表达式判断:")
System.out.println(isChinese("Hello++"))
System.out.println(isChinese("Hello++。、，？"))
System.out.println(isChinese("Hello++编程"))
System.out.println(isChinese("编程"))
System.out.println("\r\n使用Character.UnicodeBlock")
System.out.println(isChinese('h')?"中文":"英文")
System.out.println(isChinese(',')?"中文":"英文")
System.out.println(isChinese('。')?"中文":"英文")
System.out.println(isChinese('编')?"中文":"英文")
}
}
