1、对Double类型数据进行截取(转换方法1)
public static void main(String[] args) {
Double ss = 18000.2;
String test = ss+"";
String NewNum = test.substring(0,test.length()-4)+"."+test.substring(test.length()-4,test.length()-2);
Double fromString = new Double(NewNum);
System.out.println(fromString);
}

2、对Double类型数据进行截取(转换方法2)
public static void main(String[] args) {
Double ss = 18000.2;
String test = ss+"";
String NewNum = test.substring(0,test.length()-4)+"."+test.substring(test.length()-4,test.length()-2);
Double doubleString = Double.parseDouble(NewNum);
System.out.println(doubleString);
}

3、对Double类型数据进行截取(转换方法3)
public static void main(String[] args) {
Double ss = 18000.2;
String test = ss+"";
String NewNum = test.substring(0,test.length()-4)+"."+test.substring(test.length()-4,test.length()-2);
Double doubleString = Double.valueOf(NewNum);
System.out.println(doubleString);
}
