java怎么把整数转成小数_Java - 常规 - 字符串转换为整数或小数

字符串转换为数值

public class StringCheck {

public enum FormatType{

INTEGER, // "^(\\+|-)?[1-9]\\d*|0$"

DECIMALS // "^((-|\\+)?(([1-9]\\d*)|0)(\\.\\d*)?)|0$"

}

//字符串长度检查

public static boolean StringLengthInRange(String str, Integer minLength, Integer maxLength){

byte bytes[] = str.getBytes();

return (minLength <= bytes.length && bytes.length <= maxLength );

}

//整数字符串格式检查

public static boolean StringIsInteger(String str){

return Pattern.matches("^(\\+|-)?[1-9]\\d*|0$", str);

}

//小数字符串格式检查

public static boolean StringIsDecimals(String str){

return Pattern.matches("^((-|\\+)?(([1-9]\\d*)|0)(\\.\\d*)?)|0$", str);

}

//将字符串转换为Integer

public static Integer transformStringToInteger(String string){

Integer result = null;

if(StringIsInteger(string)){

result = Integer.parseInt(string);

}

return result;

}

//将字符串转换为Long

public static Long transformStringToLong(String string){

Long result = null;

if(StringIsInteger(string)){

result = Long.parseLong(string);

}

return result;

}

//将字符串转换为Double

public static Double transformStringToDecimal(String string){

Double result = null;

if(StringIsDecimals(string)){

result = Double.parseDouble(string);

}

return result;

}

}