P158 （白学）IO流

 

文件字节输入、输出流 FileInputStream、FileOutputStream

文件字符输入、输出流 FileReader、FileWriter

缓冲流自带8kb缓冲区，提高原始字节流、字符流读写数据的性能

字节缓冲输入、输出流 BufferedInputStream、BufferedOutputStream

字符缓冲输入、输出流 BufferedReader、BufferedWriter

转换流 InputStreamReader、OutputStreamWrite

对象字节输入、输出流 ObjectInputStream、ObjectOutputStream

P165 （白学）代码与文件编码不一致导致乱码问题，转换流解决

InputStreamReader、OutputStreamWriter

FileInputStream fis = new FileInputStream("test.txt");
InputStreamReader isr = new InputStreamReader(fis, "GBK");
BufferedReader br = new BufferedReader(isr);
String line;
while ((line = br.readLine()) != null) {
    System.out.println(line);
}
 
 
FileOutputStream fos = new FileOutputStream("test.txt");
OutputStreamWriter osw = new OutputStreamWriter(fos, "GBK");
BufferedWriter bw = new BufferedWriter(osw);
bw.write("这是中文");
bw.close();

P166 对象序列化、反序列化

ObjectOutputStream、ObjectInputStream

被序列化的对象，属性增加修饰符transient，可以忽略使此属性在序列化后为null（常用于敏感信息）

被序列化的对象，必须实现接口Serializable

// 序列化
Book book = new Book("name");
ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream("test.txt"));
objectOutputStream.writeObject(book);
objectOutputStream.close();
 
// 反序列化
ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream("test.txt"));
Object o = objectInputStream.readObject();
objectInputStream.close();
System.out.println(o);

P167 打印流、Properties、commons-io框架

打印流：PrintStream（字节）、PrintWriter（字符）

PrintStream printStream = new PrintStream("test.txt");
printStream.println("test");
printStream.flush();

改变输出语句的位置到文件

PrintStream ps = new PrintStream("log.txt");
System.setOut(ps);
System.out.println("test"); // 现在不会输出到console，会出现在log.txt文件中

Properties类

Properties properties = new Properties();
properties.setProperty("key1", "value1");
properties.store(new FileWriter("user.properties"), "备注信息");

commons-io框架（推荐使用）