使用Pattern And Matcher，它更具动态性。

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RemovingSpace {

    /**
     * @param args
     * Removing Space Using Matcher
     */
    public static void main(String[] args) {
        String str= "jld fdkjg jfdg ";
        String pattern="[\\s]";
        String replace="";

        Pattern p= Pattern.compile(pattern);
        Matcher m=p.matcher(str);

        str=m.replaceAll(replace);
        System.out.println(str);    
    }
}

您还可以查看下面的Java代码。以下代码不使用任何“内置”方法。

/**
 * Remove all characters from an alphanumeric string.
 */
public class RemoveCharFromAlphanumerics {

    public static void main(String[] args) {

        String inp = "01239Debashish123Pattn456aik";

        char[] out = inp.toCharArray();

        int totint=0;

        for (int i = 0; i < out.length; i++) {
            System.out.println(out[i] + " : " + (int) out[i]);
            if ((int) out[i] >= 65 && (int) out[i] <= 122) {
                out[i] = ' ';
            }
            else {
                totint+=1;
            }

        }

        System.out.println(String.valueOf(out));
        System.out.println(String.valueOf("Length: "+ out.length));

        for (int c=0; c<out.length; c++){

            System.out.println(out[c] + " : " + (int) out[c]);

            if ( (int) out[c] == 32) {
                System.out.println("Its Blank");
                 out[c] = '\'';
            }

        }

        System.out.println(String.valueOf(out));

        System.out.println("**********");
        System.out.println("**********");
        char[] whitespace = new char[totint];
        int t=0;
        for (int d=0; d< out.length; d++) {

            int fst =32;



            if ((int) out[d] >= 48 && (int) out[d] <=57 ) {

                System.out.println(out[d]);
                whitespace[t]= out[d];
                t+=1;

            }

        }

        System.out.println("**********");
        System.out.println("**********");

        System.out.println("The String is: " + String.valueOf(whitespace));

    }
}

输入：

String inp = "01239Debashish123Pattn456aik";

输出：

The String is: 01239123456

你已经从Gursel Koca那里得到了正确的答案，但我相信这很有可能不是你真正想要做的事情？

import java.util.Enumeration;
import java.util.Hashtable;

class SplitIt {
  public static void main(String args[])  {

    String person = "name=john age=13 year=2001";

    for (String p : person.split("\\s")) {
      String[] keyValue = p.split("=");
      System.out.println(keyValue[0] + " = " + keyValue[1]);
    }
  }
}

输出：name=约翰年龄=13岁年=2001

将每组文本分隔成自己的子字符串，然后连接这些子字符串：

public Address(String street, String city, String state, String zip ) {
    this.street = street;
    this.city = city;
    // Now checking to make sure that state has no spaces...
    int position = state.indexOf(" ");
    if(position >=0) {
        //now putting state back together if it has spaces...
        state = state.substring(0, position) + state.substring(position + 1);  
    }
}

您需要的代码是

str.replaceAll("\\s","");

这将删除所有空白。

如果您更喜欢实用程序类而不是正则表达式，那么Spring Framework中的StringUtils中有一个方法trimAllWhitespace（String）。