1, stream: It is an abstraction of the process of transmitting data from the producer (such as keyboard, disk file, memory, or other device) through a buffer mechanism to accept the process of accepting the data (such as screen, file or memory, etc.). 2. The relevant Java package: java.io package includes many classes to provide many aspects of the relevant documents. 3. Categories of file name and directory name: File class is independent of the system platform, using the constructor file (String Path), File (String Path, String Name), File (File Dir, String Name), etc. Create a File object; Use canread (), canwrite (), getParent (), getPath () and other member functions to implement the operation of each attribute to the file. Import java.io. *; public class filetest {public static void main (string "args) {string filename = c: /temp/myfile.dat file myfile = new file (filename); if (! myfile. exists () ) {system.err.Println (Cant Find FileName); Return;} system.out.println (file filename is myfile.length () bytes long!); if (myfile. isdirectory ()) {system.err.println File filename is a directory!); return;}}} 4, related to file content (data) operation class: 4.1 Input Output Abstract Basics InputStream / OutputStream, implementing the basic functional function of file content operation Read (), Write () , Close (), Skip (), etc .; generally create its derived class object (complete specified special features) to implement file read and write. Technologies should be paid to abnormal processing in the programming process of document reading and writing. 4.2 FileInputStream / FileOutputStream: Used for local file reading and writing (binary format reading and writing and is sequential reading and writing, reading and writing to create different file stream objects); the basic process of reading and writing programming of local files is: 1 Generate file stream Object (I should be a FileInputStream class when reading the file, and the file write should be the fileoutputstream class); 2 Call the function function in the fileInputstream or FileOutputStream class, such as read (), write (int b), etc.) read and write file content; 3 Close File (Close ()). 4.3 PipedInputStream / PipedputStream: Used for pipe input and output (directly connected to another program or a thread input port directly to another program or a thread.
