版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/qfashly/article/details/79499227
转载请注明：https://blog.csdn.net/qfashly/article/details/79499227
public class FileUtils {
private static Logger log = LoggerFactory.getLogger(FileUtils.class);
/**
* 读取文件
* @param fileName
* @return
*/
public static String readFile(String fileName) {
String str = null;
//获取通道
FileInputStream fis = null;
FileChannel channel = null;
try {
fis = new FileInputStream(fileName);
channel = fis.getChannel();
//指定缓冲区
ByteBuffer buf = ByteBuffer.allocate(1024);
//将通道中的数据读到缓冲区中
channel.read(buf);
byte[] arr = buf.array();
str = new String(arr);
} catch (FileNotFoundException e) {
log.error(fileName+"文件不存在", e);
} catch (IOException e) {
log.error("IO异常", e);
} finally {
try {
if (channel != null) {
channel.close();
}
} catch (IOException ee) {
log.error("IO异常", ee);
}
try {
if (fis != null) {
fis.close();
}
} catch (IOException ee) {
ee.printStackTrace();
log.error("IO异常", ee);
}
}
return str.toString();
}
/**
* nio写文件
* @param fileName
* @param content
* @return
*/
public static void writeFile(String fileName, String content) {
//获取通道
FileOutputStream fos = null;
FileChannel channel = null;
ByteBuffer buffer = null;
try {
fos = new FileOutputStream(fileName);
channel = fos.getChannel();
buffer = ByteBuffer.wrap(content.getBytes());
//将内容写到缓冲区
fos.flush();
channel.write(buffer);
} catch (FileNotFoundException e) {
e.printStackTrace();
log.error(fileName+"文件不存在", e);
} catch (IOException e) {
e.printStackTrace();
log.error("IO异常", e);
} finally {
try {
if (channel != null) {
channel.close();
}
} catch (IOException ee) {
log.error("IO异常", ee);
}
try {
if (fos != null) {
fos.close();
}
} catch (IOException ee) {
log.error("IO异常", ee);
}
}
}
/**
* 复制文件
* @param sourceFile
* @param desFile
*/
public static void copyFile(String sourceFile, String desFile) {
// 获取源文件和目标文件的输入输出流
FileInputStream fis = null;
FileOutputStream fos = null;
FileChannel fisChannel = null;
FileChannel fosChannel = null;
try {
fis = new FileInputStream(sourceFile);
fos = new FileOutputStream(desFile);
// 获取输入输出通道
fisChannel = fis.getChannel();
fosChannel = fos.getChannel();
// 创建缓冲区
ByteBuffer buffer = ByteBuffer.allocate(1024);
while (true) {
// clear方法重设缓冲区，使它可以接受读入的数据
buffer.clear();
// 从输入通道中将数据读到缓冲区
int r = fisChannel.read(buffer);
// read方法返回读取的字节数，可能为零，如果该通道已到达流的末尾，则返回-1
if (r == -1) {
break;
}
// flip方法让缓冲区可以将新读入的数据写入另一个通道
buffer.flip();
// 从输出通道中将数据写入缓冲区
fosChannel.write(buffer);
}
fisChannel.close();
fosChannel.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
log.error("文件不存在", e);
} catch (IOException e) {
e.printStackTrace();
log.error("IO异常", e);
} finally {
try {
if (fisChannel != null) {
fisChannel.close();
}
if (fosChannel != null) {
fosChannel.close();
}
if (fis != null) {
fis.close();
}
if (fos != null) {
fos.close();
}
} catch (IOException ee) {
log.error("IO异常", ee);
}
}
}
/**
* @Title: deleteDir
* @Description: 递归删除目录下的所有文件及子目录下所有文件
* @param dir
* @return
* @author chenxy
* @date 2018-1-17 下午3:25:01
*/
public static boolean deleteDir(File dir) {
if (dir.isDirectory()) {
String[] children = dir.list();
//递归删除目录中的子目录下
for (int i=0; i<children.length; i++) {
boolean success = deleteDir(new File(dir, children[i]));
if (!success) {
return false;
}
}
}
return dir.delete();
}
/**
* @Title: deleteFile
* @Description: 除文件夹中指定的文件类型，如果有文件夹则不删除文件夹中的文件
* @param path
* @param fileType
* @author chenxy
* @date 2018-1-18 上午9:38:46
*/
public static void deleteFile(String path, String fileType){
if(StringUtils.isNullOrBlank(path)){
return;
}
File file = new File(path);
if(file.isFile()){//文件
File[] listFiles = {file};
deleteFileByType(listFiles, fileType);
}
if(file.isDirectory()){//文件夹
File[] listFiles = file.listFiles();
deleteFileByType(listFiles, fileType);
}
}
/**
* @Title: cycleDeleteFile
* @Description: 循环删除文件夹中指定的文件类型
* @param path
* @param fileType
* @author chenxy
* @date 2018-1-18 上午9:37:49
*/
public static void cycleDeleteFile(String path, String fileType){
if(StringUtils.isNullOrBlank(path)){
return;
}
File file = new File(path);
if(file.isFile()){//文件
File[] listFiles = {file};
deleteFileByType(listFiles, fileType);
}
if(file.isDirectory()){//文件夹
String[] files = file.list();
for(String filePath : files){
cycleDeleteFile(file.getPath() + File.separator + filePath, fileType);
}
}
}
/**
* @Title: deleteFileByType
* @Description: 判断文件是否是指定的类型，如果是则删除之
* @param listFiles
* @param fileType
* @author chenxy
* @date 2018-1-18 上午9:39:24
*/
public static void deleteFileByType(File[] listFiles, String fileType) {
if(listFiles == null || listFiles.length <= 0){
return;
}
String suffixName = "";
for(File file : listFiles){
if(!file.isFile()){//文件
continue;
}
suffixName = getSuffixName(file);
if(StringUtils.isNullOrBlank(suffixName)){
continue;
}
if(fileType.equals(suffixName)){
if(!file.delete()){
log.error("删除" + file.getPath() + "失败");
}
}
}
}
/**
* @Title: getSuffixName
* @Description: 放回文件的后缀名, 如JPEG：FFD8FF
* @param file
* @return
* @author chenxy
* @date 2018-1-18 上午9:45:03
*/
public static String getSuffixName(File file){
if(!file.isFile()){
return null;
}
FileInputStream is = null;
byte[] src = new byte[3];
StringBuilder sBuilder = null;
String hv = null;
try {
is = new FileInputStream(file);
src = new byte[3];
is.read(src, 0, src.length);
is.close();
} catch (FileNotFoundException e1) {
e1.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
}
if (src == null || src.length <= 0) {
return null;
}
sBuilder = new StringBuilder();
for (int i = 0; i < src.length; i++) {
int v = src[i] & 0xFF;
hv = Integer.toHexString(v);
if (hv.length() < 2) {
sBuilder.append(0);
}
sBuilder.append(hv);
}
if(sBuilder.length() <= 0){
return null;
}
return sBuilder.toString().toUpperCase();
}
/**
* @Title: getFile
* @Description: 获取文件夹中所有的文件
* @param path
* @param fileList
* @author chenxy
* @date 2018-1-18 上午10:32:13
*/
public static void getFile(String path, ArrayList<File> fileList){
File file = new File(path);
if(file.isFile()){
fileList.add(file);
return;
}
String[] files = file.list();
for(String filePath : files){
getFile(file.getPath() + File.separator + filePath, fileList);
}
}
public static void main(String[] args){
String path = "D:\\Log";
// 776569 log
// 89504E png
cycleDeleteFile(path, AppContant.SuffixName.LOG);
/*String path = "D:\\Log";
ArrayList<File> fileList = new ArrayList<File>();
getFile(path, fileList);
Map<String, String> map = new HashMap<String, String>();
String[] strs = null;
for(File file : fileList){
strs = file.getPath().split("\\.");
if(strs.length < 2){
continue;
}
map.put(strs[strs.length - 1], getSuffixName(file));
//System.out.println(" " + getSuffixName(file) + " = " + file.getPath());
}
for(Entry<String, String> entry : map.entrySet()){
System.out.println(" " + entry.getKey() + " = " + entry.getValue());
}*/
}
}