java去全半角空格,trim(), replaceAll(" +",""),replaceAll("\\s*", ""), replaceAll(" | ", "")

JAVA中去掉空格  
 
1. String.trim() 
trim()是去掉首尾空格 
 
2.str.replace(" ", ""); 去掉所有空格，包括首尾、中间 
String str = " hell o "; 
String str2 = str.replaceAll(" ", ""); 
System.out.println(str2); 

3.或者replaceAll(" +",""); 去掉所有空格 

4.str = .replaceAll("\\s*", ""); 
可以替换大部分空白字符， 不限于空格  
\s 可以匹配空格、制表符、换页符等空白字符的其中任意一个 


java去掉全角空格和半角空格的方法,
需求1：将字符串转换成字符数组
String value = "　　俞子东 ";
        char[] val = new char[value.length()];
        value.getChars(0, value.length(), val, 0);//字符串转换成字符数组
        System.out.println(val.length)

需求2：将所有的全角空格和半角空格去掉
System.out.println(value.replaceAll("　| ", ""));

需求3：将字符串两边的半角空格、全角空格去掉（调用myTrim(value, " 　");）
static String myTrim(String source, String toTrim) {//将字符串两边的半角空格、全角空格去掉，其他也可以
        StringBuffer sb = new StringBuffer(source);
        while (toTrim.indexOf(new Character(sb.charAt(0)).toString()) != -1) {
            sb.deleteCharAt(0);
        }
        while (toTrim.indexOf(new Character(sb.charAt(sb.length() - 1))
                .toString()) != -1) {
            sb.deleteCharAt(sb.length() - 1);
        }
        return sb.toString();
    }

完整代码：
package com.konglong.test;
public class TrimTest {
    public static void main(String[] args) {
        String value = "　　俞子东 ";
        char[] val = new char[value.length()];
        value.getChars(0, value.length(), val, 0);//字符串转换成字符数组
        System.out.println(val.length);
        System.out.println(value.replaceAll("　| ", ""));
        System.out.println(myTrim(value, " 　"));
    }
    static String myTrim(String source, String toTrim) {//将字符串两边的半角空格、全角空格去掉，其他也可以
        StringBuffer sb = new StringBuffer(source);
        while (toTrim.indexOf(new Character(sb.charAt(0)).toString()) != -1) {
            sb.deleteCharAt(0);
        }
        while (toTrim.indexOf(new Character(sb.charAt(sb.length() - 1))
                .toString()) != -1) {
            sb.deleteCharAt(sb.length() - 1);
        }
        return sb.toString();
    }
}