下面是字符串,例如:
"Apple"
我想加零来填充8个字符:
"000Apple"
我该怎么做呢?
下面是字符串,例如:
"Apple"
我想加零来填充8个字符:
"000Apple"
我该怎么做呢?
当前回答
public class LeadingZerosExample {
public static void main(String[] args) {
int number = 1500;
// String format below will add leading zeros (the %0 syntax)
// to the number above.
// The length of the formatted string will be 7 characters.
String formatted = String.format("%07d", number);
System.out.println("Number with leading zeros: " + formatted);
}
}
其他回答
这并不漂亮,但很有效。如果你有apache commons,我建议你使用它
if (val.length() < 8) {
for (int i = 0; i < val - 8; i++) {
val = "0" + val;
}
}
我也遇到过类似的情况,我用了这个;它是非常简洁的,你不需要处理长度或其他库。
String str = String.format("%8s","Apple");
str = str.replace(' ','0');
简单而利落。字符串格式返回“Apple”,因此在用零替换空格后,它会给出所需的结果。
你可能得处理edgecase。这是一个泛型方法。
public class Test {
public static void main(String[] args){
System.out.println(padCharacter("0",8,"hello"));
}
public static String padCharacter(String c, int num, String str){
for(int i=0;i<=num-str.length()+1;i++){str = c+str;}
return str;
}
}
有人尝试过这个纯Java解决方案吗(没有SpringUtils):
//decimal to hex string 1=> 01, 10=>0A,..
String.format("%1$2s", Integer.toString(1,16) ).replace(" ","0");
//reply to original question, string with leading zeros.
//first generates a 10 char long string with leading spaces, and then spaces are
//replaced by a zero string.
String.format("%1$10s", "mystring" ).replace(" ","0");
不幸的是,这个解决方案只有在字符串中没有空格时才有效。
public class PaddingLeft {
public static void main(String[] args) {
String input = "Apple";
String result = "00000000" + input;
int length = result.length();
result = result.substring(length - 8, length);
System.out.println(result);
}
}