java-IO字节流、字符流介绍及应用（读取数据、写入数据）

### 字节输入流：InputStream（从缓冲区读取到本地）可对应reader使用

1、FileInputStream

2、BufferedInputStream

### 字节输出流：OutputStream（本地数据写入到缓冲流）可对应writer使用

1、FileOutputStream

2、BufferedOutputStream
        OutputStream is = null;
        is = new FileOutputStream(new File("c:\a.txt","UTF-8"));
        is.write("写入数据".getBytes());
        is.flush();

### 字符输入流：Reader（从缓冲流中把数据读到客户端）

1、BufferedReader
构造器**BufferedReader**(**Reader** in);

2、InputStreamReader转换流子类FileReader
构造器**InputStreamReader**(**InputStream** in, String charsetName);
            FileReader(File file);

BufferedReader br = new BufferedReader(new InputStreamReader(new InputStream()));
String s = br.readLine;
StringBuilder sb = new StringBuilder();
while(null!= s){
    sb.append(s);
}

BufferedReader br = new BufferedReader(new FileReader(new File("C:\\work\\a.txt")))//从a.txt读取字符串
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(new File("C:\\work\\a.txt"))));//从a.txt读取字符串

### 字符输出流：Writer（针对客户端写操作，即从本地写入到缓冲流中。）

1、BufferedWriter
构造器BufferedWriter(Writer wi);

2、OutputStreamWriter转换流FileWriter
构造器OutputStreamWriter(OutputStream os);
            FileWriter(File file);

//新建一个a.txt文件，并写入
OutputStream os = new FileOutputStream("C:\a.txt"),"UTF-8");
OutputStreamWriter ows = new OutputStreamWriter(os);
BufferedWriter bw = new BufferedWriter(ows);