File,Byte[],Object相互转化.

客官°小女子只卖身不卖艺 2022-06-02 07:21 185阅读 0赞

import java.io.BufferedOutputStream;
    import java.io.ByteArrayInputStream;
    import java.io.ByteArrayOutputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.ObjectInputStream;
    import java.io.ObjectOutputStream;
    import java.io.Serializable;
    
    public class FileUtil { 
    
        /** * . * TODO 把字节数组保存为一个文件 * @param f * @return */
        public byte[] getBytesFromFile(File f) {
            if (f == null) {
                return null;
            }
            try {
                FileInputStream stream = new FileInputStream(f);
                ByteArrayOutputStream out = new ByteArrayOutputStream(1000);
                byte[] b = new byte[1000];
                int n;
                while ((n = stream.read(b)) != -1)
                    out.write(b, 0, n);
                stream.close();
                out.close();
                return out.toByteArray();
            } catch (IOException e) {
            }
            return null;
        }
    
        /** * . * TODO 把字节数组保存为一个文件 * @param b * @param outputFile * @return */
        public File getFileFromBytes(byte[] b, String outputFile) {
            BufferedOutputStream stream = null;
            File file = null;
            try {
                file = new File(outputFile);
                FileOutputStream fstream = new FileOutputStream(file);
                stream = new BufferedOutputStream(fstream);
                stream.write(b);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (stream != null) {
                    try {
                        stream.close();
                    } catch (IOException e1) {
                        e1.printStackTrace();
                    }
                }
            }
            return file;
        }
    
        /** * . * TODO 从字节数组获取对象 * @param objBytes * @return */
        public Object getObjectFromBytes(byte[] objBytes) throws Exception {
            if (objBytes == null || objBytes.length == 0) {
                return null;
            }
            ByteArrayInputStream bi = new ByteArrayInputStream(objBytes);
            ObjectInputStream oi = new ObjectInputStream(bi);
            return oi.readObject();
        }
    
        /** * . * TODO 从对象获取一个字节数组 * @param obj * @return */
        public byte[] getBytesFromObject(Serializable obj) throws Exception {
            if (obj == null) {
                return null;
            }
            ByteArrayOutputStream bo = new ByteArrayOutputStream();
            ObjectOutputStream oo = new ObjectOutputStream(bo);
            oo.writeObject(obj);
            return bo.toByteArray();
        }
    
    }