Android 获取文件大小

public class FileSizeUtil {
public static final int SIZETYPE_B = 1;//获取文件大小单位为B的double值
public static final int SIZETYPE_KB = 2;//获取文件大小单位为KB的double值
public static final int SIZETYPE_MB = 3;//获取文件大小单位为MB的double值
public static final int SIZETYPE_GB = 4;//获取文件大小单位为GB的double值
/**
* 获取文件指定文件的指定单位的大小
* @param filePath 文件路径
* @param sizeType 获取大小的类型1为B、2为KB、3为MB、4为GB
* @return double值的大小
*/
public static double getFileOrFilesSize(String filePath,int sizeType){
File file=new File(filePath);
long blockSize=0;
try {
if(file.isDirectory()){
blockSize = getFileSizes(file);
}else{
blockSize = getFileSize(file);
}
} catch (Exception e) {
e.printStackTrace();
Log.e("获取文件大小","获取失败!");
}
return FormetFileSize(blockSize, sizeType);
}
/**
* 调用此方法自动计算指定文件或指定文件夹的大小
* @param filePath 文件路径
* @return 计算好的带B、KB、MB、GB的字符串
*/
public static String getAutoFileOrFilesSize(String filePath){
File file=new File(filePath);
long blockSize=0;
try {
if(file.isDirectory()){
blockSize = getFileSizes(file);
}else{
blockSize = getFileSize(file);
}
} catch (Exception e) {
e.printStackTrace();
Log.e("获取文件大小","获取失败!");
}
return FormetFileSize(blockSize);
}
/**
* 获取指定文件大小
* @param f
* @return
* @throws Exception
*/
private static long getFileSize(File file) throws Exception
{
long size = 0;
 if (file.exists()){
 FileInputStream fis = null;
 fis = new FileInputStream(file);
 size = fis.available();
 }
 else{
 file.createNewFile();
 Log.e("获取文件大小","文件不存在!");
 }
 return size;
}
 
/**
* 获取指定文件夹
* @param f
* @return
* @throws Exception
*/
private static long getFileSizes(File f) throws Exception
{
long size = 0;
File flist[] = f.listFiles();
for (int i = 0; i < flist.length; i++){
if (flist[i].isDirectory()){
size = size + getFileSizes(flist[i]);
}
else{
size =size + getFileSize(flist[i]);
}
}
return size;
}
/**
 * 转换文件大小
 * @param fileS
 * @return
 */
private static String FormetFileSize(long fileS)
{
DecimalFormat df = new DecimalFormat("#.00");
String fileSizeString = "";
String wrongSize="0B";
if(fileS==0){
return wrongSize;
}
if (fileS < 1024){
fileSizeString = df.format((double) fileS) + "B";
 }
else if (fileS < 1048576){
fileSizeString = df.format((double) fileS / 1024) + "KB";
}
else if (fileS < 1073741824){
    fileSizeString = df.format((double) fileS / 1048576) + "MB";
  }
else{
    fileSizeString = df.format((double) fileS / 1073741824) + "GB";
  }
return fileSizeString;
}
/**
 * 转换文件大小,指定转换的类型
 * @param fileS 
 * @param sizeType 
 * @return
 */
private static double FormetFileSize(long fileS,int sizeType)
{
DecimalFormat df = new DecimalFormat("#.00");
double fileSizeLong = 0;
switch (sizeType) {
case SIZETYPE_B:
fileSizeLong=Double.valueOf(df.format((double) fileS));
break;
case SIZETYPE_KB:
fileSizeLong=Double.valueOf(df.format((double) fileS / 1024));
break;
case SIZETYPE_MB:
fileSizeLong=Double.valueOf(df.format((double) fileS / 1048576));
break;
case SIZETYPE_GB:
fileSizeLong=Double.valueOf(df.format((double) fileS / 1073741824));
break;
default:
break;
}
return fileSizeLong;
}