(java)for循环让一个字符串数组得到一个文件夹下所有文件名却报空指针错误

代码是：
String[] absoluteFilePath = null;
try {
File file = new File(filePath);
if( file.isDirectory()) {
System.out.println("文件夹");
String[] fileList = file.list();

for (int i = 0; i < fileList.length; i++) {

File fullFile = new File(filePath + "\" + fileList[i]);

absoluteFilePath[i] = fullFile.getAbsolutePath();
System.out.println("absoluteFilePath=" + absoluteFilePath[i]);

}
}
}

然后会在 absoluteFilePath[i] = fullFile.getAbsolutePath(); 这一行报java.lang.NullPointerException

File fullFile = new File(filePath + "\" + fileList[i]);//这里的单斜杠是不是要改成双斜杠；

如果回答对您有帮助，请采纳

String[] absoluteFilePath = null;
……
absoluteFilePath[i] = fullFile.getAbsolutePath();

你没有初始化就是用这个数组了