package cn.stylefeng.guns.workflow.core.util;
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import java.io.*;
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import java.nio.ByteBuffer;
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import java.nio.MappedByteBuffer;
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import java.nio.channels.FileChannel;
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import java.nio.channels.FileChannel.MapMode;
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/**
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* 文件处理
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*
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* @author fengshuonan
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* @Date 2019/8/7 23:14
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*/
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public class FileUtil {
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/**
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* 获取文件大小 返回 KB 保留3位小数 没有文件时返回0
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*
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* @param filepath 文件完整路径，包括文件名
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* @return
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*/
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public static Double getFilesize(String filepath) {
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File backupath = new File(filepath);
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return Double.valueOf(backupath.length()) / 1000.000;
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}
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/**
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* 创建目录
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*
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* @param destDirName目标目录名
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* @return
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*/
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public static Boolean createDir(String destDirName) {
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File dir = new File(destDirName);
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if (!dir.getParentFile().exists()) { //判断有没有父路径，就是判断文件整个路径是否存在
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return dir.getParentFile().mkdirs(); //不存在就全部创建
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}
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return false;
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}
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/**
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* 删除文件
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*
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* @param filePathAndName String 文件路径及名称 如c:/fqf.txt
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* @param fileContent String
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* @return boolean
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*/
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public static void delFile(String filePathAndName) {
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try {
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String filePath = filePathAndName;
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filePath = filePath.toString();
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java.io.File myDelFile = new java.io.File(filePath);
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myDelFile.delete();
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} catch (Exception e) {
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System.out.println("删除文件操作出错");
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e.printStackTrace();
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}
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}
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/**
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* 读取到字节数组0
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*
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* @param filePath //路径
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* @throws IOException
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*/
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public static byte[] getContent(String filePath) throws IOException {
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File file = new File(filePath);
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long fileSize = file.length();
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if (fileSize > Integer.MAX_VALUE) {
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System.out.println("file too big...");
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return null;
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}
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FileInputStream fi = new FileInputStream(file);
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byte[] buffer = new byte[(int) fileSize];
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int offset = 0;
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int numRead = 0;
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while (offset < buffer.length
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&& (numRead = fi.read(buffer, offset, buffer.length - offset)) >= 0) {
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offset += numRead;
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}
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// 确保所有数据均被读取
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if (offset != buffer.length) {
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throw new IOException("Could not completely read file " + file.getName());
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}
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fi.close();
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return buffer;
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}
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/**
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* 读取到字节数组1
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*
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* @param filePath
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* @return
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* @throws IOException
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*/
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public static byte[] toByteArray(String filePath) throws IOException {
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File f = new File(filePath);
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if (!f.exists()) {
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throw new FileNotFoundException(filePath);
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}
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ByteArrayOutputStream bos = new ByteArrayOutputStream((int) f.length());
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BufferedInputStream in = null;
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try {
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in = new BufferedInputStream(new FileInputStream(f));
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int buf_size = 1024;
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byte[] buffer = new byte[buf_size];
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int len = 0;
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while (-1 != (len = in.read(buffer, 0, buf_size))) {
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bos.write(buffer, 0, len);
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}
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return bos.toByteArray();
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} catch (IOException e) {
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e.printStackTrace();
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throw e;
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} finally {
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try {
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in.close();
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} catch (IOException e) {
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e.printStackTrace();
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}
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bos.close();
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}
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}
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/**
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* 读取到字节数组2
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*
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* @param filePath
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* @return
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* @throws IOException
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*/
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public static byte[] toByteArray2(String filePath) throws IOException {
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File f = new File(filePath);
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if (!f.exists()) {
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throw new FileNotFoundException(filePath);
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}
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FileChannel channel = null;
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FileInputStream fs = null;
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try {
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fs = new FileInputStream(f);
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channel = fs.getChannel();
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ByteBuffer byteBuffer = ByteBuffer.allocate((int) channel.size());
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while ((channel.read(byteBuffer)) > 0) {
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// do nothing
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// System.out.println("reading");
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}
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return byteBuffer.array();
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} catch (IOException e) {
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e.printStackTrace();
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throw e;
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} finally {
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try {
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channel.close();
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} catch (IOException e) {
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e.printStackTrace();
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}
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try {
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fs.close();
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} catch (IOException e) {
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e.printStackTrace();
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}
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}
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}
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/**
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* Mapped File way MappedByteBuffer 可以在处理大文件时，提升性能
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*
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* @param filename
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* @return
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* @throws IOException
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*/
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public static byte[] toByteArray3(String filePath) throws IOException {
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FileChannel fc = null;
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RandomAccessFile rf = null;
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try {
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rf = new RandomAccessFile(filePath, "r");
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fc = rf.getChannel();
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MappedByteBuffer byteBuffer = fc.map(MapMode.READ_ONLY, 0,
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fc.size()).load();
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//System.out.println(byteBuffer.isLoaded());
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byte[] result = new byte[(int) fc.size()];
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if (byteBuffer.remaining() > 0) {
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// System.out.println("remain");
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byteBuffer.get(result, 0, byteBuffer.remaining());
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}
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return result;
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} catch (IOException e) {
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e.printStackTrace();
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throw e;
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} finally {
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try {
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rf.close();
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fc.close();
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} catch (IOException e) {
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e.printStackTrace();
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}
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}
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}
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}
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