Android判断字符串中是否含字母、中文或数字

/**
 * 必须包含数字、中文、字母
 * www.yoodb.com
 * @param str
 * @return
 */
public static boolean isLetterDigit(String str) {
 boolean isDigit = false;
 boolean isLetter = false;
 for (int i = 0; i < str.length(); i++) {
 if (Character.isDigit(str.charAt(i))) {
  isDigit = true;
 }
 if (Character.isLetter(str.charAt(i))) {
  isLetter = true;
 }
 }
 String regex = "^[a-zA-Z0-9]+$";
 boolean isRight = isDigit && isLetter && str.matches(regex);
 return isRight;
}

/**
 * 必须包含数字、中文、字母
 * @param str
 * www.yoodb.com
 * @return
 */
String txt = edInput.getText().toString();
Pattern p = Pattern.compile("[0-9]*"); 
Matcher m = p.matcher(txt); 
if(m.matches() ){
 Toast.makeText(Main.this,"输入是数字！", Toast.LENGTH_SHORT).show();
} 
p = Pattern.compile("[a-zA-Z]");
m = p.matcher(txt);
if(m.matches()){
 Toast.makeText(Main.this,"输入是字母！", Toast.LENGTH_SHORT).show();
}
p = Pattern.compile("[\u4e00-\u9fa5]");
m = p.matcher(txt);
if(m.matches()){
 Toast.makeText(Main.this,"输入是汉字！", Toast.LENGTH_SHORT).show();
}