java从字符串中提取数字的简单实例

package 测试练习;
import Java.util.*;
public class get_StringNum {


/**
 *2016.10.25
 */

public static void main(String[] args) {
String str = "love23next234csdn3423javaeye";
str=str.trim();
String str2="";
if(str != null && !"".equals(str)){
for(int i=0;i<str.length();i++){
if(str.charAt(i)>=48 && str.charAt(i)<=57){
str2+=str.charAt(i);
}
}

}
System.out.println(str2);
}

}

output:

232343423

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class get_StringNum {


/**
 *2016.10.25
 */

public static void main(String[] args) {
String a="love23next234csdn3423javaeye";
String regEx="[^0-9]";  
Pattern p = Pattern.compile(regEx);  
Matcher m = p.matcher(a);  
System.out.println( m.replaceAll("").trim());
}

}

output:

232343423

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class get_StringNum {


/**
 *2016.10.25
 */

public static void main(String[] args) {
  String a="love23next234csdn3423javaeye";
List<String> digitList = new ArrayList<String>();
Pattern p = Pattern.compile("[^0-9]");
Matcher m = p.matcher(a);
String result = m.replaceAll("");
for (int i = 0; i < result.length(); i++) {
digitList.add(result.substring(i, i+1));

}
System.out.println(digitList);

}

}

output:

[2, 3, 2, 3, 4, 3, 4, 2, 3]

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class get_StringNum {


/**
 *2016.10.25
 */

public static void main(String[] args) {
        String a="love23next234csdn3423javaeye";
    List<String> ss = new ArrayList<String>();
    for(String sss:s.replaceAll("[^0-9]", ",").split(",")){
      if (sss.length()>0)
        ss.add(sss);
    }
    System.out.print(ss);


}

}

output:

[2, 3, 2, 3, 4, 3, 4, 2, 3]

/**
 * 从字符串文本中获得数字 

*@param
 text 

*@return
 

*/
 

publicstatic
 List<Long>
 getDigit(String text) { 

List<Long>
 digitList =new
 ArrayList<Long>();
 

Pattern p=
 Pattern.compile("(\\d+)");
 

Matcher m=
 p.matcher(text); 

while
 (m.find()) { 

String find=
 m.group(1).toString(); 

digitList.add(Long.valueOf(find)); 

}return
 digitList; 

}

// 判断一个字符串是否都为数字 
public boolean isDigit(String strNum) { 
  return strNum.matches("[0-9]{1,}"); 
} 
 
// 判断一个字符串是否都为数字 
public boolean isDigit(String strNum) { 
  Pattern pattern = Pattern.compile("[0-9]{1,}"); 
  Matcher matcher = pattern.matcher((CharSequence) strNum); 
  return matcher.matches(); 
} 
 
  //截取数字 
  public String getNumbers(String content) { 
    Pattern pattern = Pattern.compile("\\d+"); 
    Matcher matcher = pattern.matcher(content); 
    while (matcher.find()) { 
      return matcher.group(0); 
    } 
    return ""; 
  } 
 
// 截取非数字 
public String splitNotNumber(String content) { 
  Pattern pattern = Pattern.compile("\\D+"); 
  Matcher matcher = pattern.matcher(content); 
  while (matcher.find()) { 
    return matcher.group(0); 
  } 
  return ""; 
}