使用apache字符串util类更好地避免NullPointerException

org.apache.commons.lang3.StringUtils.replace("abc def ", " ", "")

输出

abcdef

如果您也需要删除不可破坏的空格，可以这样升级代码：

st.replaceAll("[\\s|\\u00A0]+", "");

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);  
    }
}

package com.sanjayacchana.challangingprograms;

public class RemoveAllWhiteSpacesInString {

    public static void main(String[] args) {
        
        String str = "name=john age=13 year=2001";
        
        str = str.replaceAll("\\s", ""); 
        
        System.out.println(str);
        
        
    }

}

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）。

使用apache字符串util类更好地避免NullPointerException

org.apache.commons.lang3.StringUtils.replace("abc def ", " ", "")

输出

abcdef