java io ioexception

1. I spoke to you about Java's Io features yesterday. Now I should be able to read and write text files and binary files. But in some special cases, we need faster Io operations, let's talk about Java. NIO. * package; 2. for faster I/O operations, we usually use a structure similar to the way in which the operating system executes

the CPU,Instead, the data is saved to buffer via channel channels, and the CPU reads and writes data directly from the buffer area, and reads and writes more content at a time.The reason for increasing IO efficiency using buffer (here is the same principle as the Bufferedxxstream, BufferedReader, and bufferedwriter in IO flow): The time spent on Io is mainly on

1. Understanding and classification of streamsThe IO class architecture of 2,java processing stream3, byte stream and character stream conversionOverview of 4,nio5,java IO shutdown Resource1. Understanding and classification of streamsA stream is a set of sequences of bytes that have a starting point and an end point,

readFloat ). With the corresponding DataInputStream, we can use the data "stream" to migrate basic data types from one place to another. Other FilterInputStream classes are used to internally modify the InputStream behavior mode: whether to buffer or retain the rows it has read (allow us to query the number of rows or set the number of rows ), and whether to push a single character back to the input stream. The last two classes seem to be more like creating a compiler (they may be added to supp

(IOException e) {System.out.println ("IO problem") Span style= "color: #000000"); }}} This program contains an try...catch...finally exception handler. Refer to Java Advanced 02 exception handlingdecorators and functional combinationsThe key to program IO is to create a BufferedReader object br:BufferedRea

the found characters.2. The byte stream can handle all types of data, such as: Pictures, Mp3,avi video files, and character streams can only handle characters data. As long as you are dealing with plain text data, you should prioritize the use of character streams, in addition to byte streams.One, the word stream:　　1, byte output stream: FileOutputStreamConstruction Method:Public fileoutputstream (file file)Public FileOutputStream (String name)Public FileOutputStream (String name,boolean append

()); byte [] bytearray=Byteout.tobytearray (); String str=new string (byteArray); System.out.println (str); //Strengthenreads a character from the input stream, then capitalizes the character and writes it to the output stream Public Static voidMain (string[] args)throwsIOException {/*Example 1 uses Bytearrayinputstream and Bytearrayoutputstream bytearrayinputstream in=new bytearrayinputstream ("abcdef". GetB Ytes ()); Bytearrayoutputstream out=new Bytearrayo

Common APIs for Java-IO stream File, javaiofileapi File class 1. It is only used to indicate the information (name, size, etc.) of the file (directory) and cannot be used to access the file content. Package cn. test; import java. io. file; import java.

This article is intended to illustrate the basic methods and processes of Java file IO operations as an example.Source1 ImportJava.io.*;2 3 Public classMain {4 Final StaticString filename= "Alice.txt";5 //file name6 Public Static voidMain (string[] args) {7 intCount=1;8String dir=system.getproperty ("User.dir");9SYSTEM.OUT.PRINTLN ("The default dir is" +dir);Ten //Show current

be explicitly manipulated when initialized to a file//file that is created into the specified directory and overwritten if the file exists.//FileWriter FW = new FileWriter ("Demo.txt", True ); FileWriter FW = new FileWriter ("Demo.txt"); Invokes the writer method, writes the string to the stream, but does not yet save the file to Fw.write ("Litiepeng"), flushes the buffer in the Stream object, writes the data in the stream to the file Fw.flush ();//Closes the stream resource, However, the d

new File ("/home/siu/work/demo.txt "); File f2 = new File (childPath ); // Create a file object in the parent directory File d = new File (path ); // Create a new File object using an existing parent directory object and a sub-File File f3 = new File (d, "hello.txt "); System. out. println ("f1 path" + f1 ); System. out. println ("f2 path" + f2 ); System. out. println ("f3 path" + f3 ); } } After compilation, the absolute path pointed to by each File object is displayed. Instance 2: Create and

Create write stream FileOutputStream Object Association write file Use Sequenceinputstream objects and FileOutputStream object read data for repeated read and write operations. Here's a sample code: merge three files into one file.classSequenceinputstreamdemo { Public Static voidMain (string[] args) throws IOException {//Create a vector collection and add related flow objectsVectorNewVector(); Vector.add (NewFileInputStream ("Book1.txt")

stream; Double, accounting for 8 bytes Dos.writeboolean (true); Boolean type, accounting for one byte bytearrayinputstream bais=new bytearrayinputstream (Baos.tobytearray ()); System.out.println (Bais.available ()); Total number of bytes available in the output stream--9 datainputstream dis=new datainputstream (Bais); The data stream "pipe" System.out.println (dis.readdouble ()) is also connected outside the output stream. The number System.out.

An overviewProblems that have been learned by common objects for APIs:String string--manipulate text data.The string buffer---container, which can store many arbitrary types of data--strings.The basic data type wrapper class---resolves the conversion between the string and the base data type "123"--parseint--123. It also provides more operations to the basic data. --tobinarystring ()Set frame--more objects, easy to store after operation. Add put Collection--iterator Map-set-iteratorMath: Solving

string */public static void function () throws Ioexcept ion{String s = fileutils.readfiletostring (new File ("C:\\a.txt")); System.out.println (s); }5. Writing text/* * Fileutils Tool class method * static void Writestringtofile (file src,string date) * Writes a string directly to the file */public static void Function_1 () Throws Ioexception{fileutils.writestringtofile (New File ("C:\\b.txt"), "I love Java