第09章—JAVA输入输出.pptVIP

Java语言程序设计;第九章 JAVA输入/输出;概念;概念;概念;第九章 JAVA输入输出;Java 基本I/O类;Java基本I/O类;Java I/O类;Java I/O类;Java I/O类;Java I/O类;Java I/O类;Java I/O类;Java I/O类;第九章 JAVA输入输出;Java I/O操作;输出: 控制台屏幕打印 class HelloWorld { public static void main(String args[]) { System.out.println(Hello World!); } };输入: 键盘读入 import java.io.IOException; class Test { public static void main(String args[]) throws IOException { byte[] b = new byte[10]; System.in.read(b)); for (int i = 0; i b.length; i++) System.out.println((char)b[i]); } };文件读/写流程 打开文件流:创建流对象 条件判断 读出/写入 关闭文件流 两种类型文件 FileInputStream/FileOutputStream (字节流) FileReader/FileWriter (字符流);字节流构造方法 public FileInputStream(File file) throws FileNotFoundException public FileInputStream(String name) throws FileNotFoundException public File(String pathname) public FileOutputStream(File file) throws FileNotFoundException public FileOutputStream(File file, boolean append) throws FileNotFoundException //是否向已存在的文件后添加 public FileOutputStream(String name) throws FileNotFoundException public FileOutputStream(String name, boolean append) throws FileNotFoundException;文件读写-实例1;字符流构造方法: public FileReader(File file) throws FileNotFoundException public FileReader(String fileName) throws FileNotFoundException public File(String pathname) public FileWriter(File file) throws IOException public FileWriter(File file, boolean append) throws IOException public FileWriter(String fileName) throws IOException public FileWriter(String fileName, boolean append) throws IOException;文件读写-实例2;通过缓冲操作，可降低实际的I/O操作次数，提高读/写的效率。 两类缓冲流 针对字节流 java.io.BufferedInputStream类 java.io.BufferedOutputStream类 针对字符流 java.io.BufferedReader类 java.io.BufferedWriter类;构造方法 public BufferedInputStream(InputStream in) 2048 bytes public BufferedInputStream(InputStream in, int size) public BufferedOutputStream(OutputStream out) 512 bytes public BufferedOutputStream(OutputStream out, int size) public BufferedRea