随笔-I/O流

InputStream

--FileInputStream

--ByteArrayInputStream

--FilterInputStream

---BufferedInputStream

如：BufferedInputStream input=new BufferedInputStream(new FileInputStream("baidu"));

---DataInputStream

如：

DataOutputStream ds=new DataOutputStream(conn.getOutputStream());

ds.writeBytes("\r\n");
    ds.writeBytes(encode(value) + "\r\n");

// 对包含中文的字符串进行转码，此为UTF-8。服务器那边要进行一次解码
    private String encode(String value) throws Exception {
        return URLEncoder.encode(value, "UTF-8");
    }

--ObjectInputStream

如：ObjectInputStream objectInputStream=new ObjectInputStream(new FileInputStream(name));

Member member= (Member) objectInputStream.readObject();

OutputStream

--FileOutputStream

--ByteArrayOutputStream

如：ByteArrayOutputStream out = new ByteArrayOutputStream();

for (int n = -1; (n = input.read(buffer)) != -1;)

out.write(buffer, 0, n); //buffer就是输出的数据，如果控制台想打印就直接输出buffer

System.out.println(new String(out.toByteArray()));

--FilterOutputStream

---BufferedOutputStream

如：

BufferedOutputStream out2=new BufferedOutputStream(new FileOutputStream("baidu"));

byte[] buffer = new byte[1024];

for (int k=0;(k = input.read(buffer)) != -1;) {//input 是BufferedInputStream input=new     //BufferedInputStream(new FileInputStream("baidu"));

out2.write(buffer, 0, k);
}

---DataOutputStream（基本类型 ，String）

---PrintStream

--ObjectOutputStream

如：Member b=new Member();

ObjectOutputStream objectOut=new ObjectOutputStream(new FileOutputStream(b.getName())) ;
    objectOut.writeObject(b);

利用ByteArrayOutputStream复制文件

public static void saveFiles(String origPath, String destPath) throws Exception {
        File file = new File(origPath);
        if (!file.exists() || file.isDirectory())
            throw new FileNotFoundException();
        BufferedInputStream in = new BufferedInputStream(
                new FileInputStream(file));
        ByteArrayOutputStream out = new ByteArrayOutputStream(1024);
        byte[] temp = new byte[1024];
        int size = 0;
        while ((size = in.read(temp)) != -1) {
            out.write(temp, 0, size);
        }
        in.close();
        String str1 = out.toString("gbk"); //得到字符串
        File file1 = new File(destPath);
        FileOutputStream fos = new FileOutputStream(file1);
        fos.write(str1.getBytes("utf-8")); //输出

}

Reader

--StringReader

--CharArrayReader

--InputStreamReader （可以指定编码)

--FileReader

--BufferedReader

如：BufferedReader reader=new BufferedReader(new InputStreamReader(new FileInputStream("z1"),System.getProperty("file.encoding")));

Writer

--StringWriter

--CharArrayWriter

--InputStreamWriter （可以指定编码)

--FileWriter

--BufferedWriter

如：BufferedWriter w=new BufferedWriter(new OutputStreamWriter(new FileOutputStream("OutputStreamWriter")));

char[] data=new char[1024];
        int length=0;
        while((length = input.read(data)) != -1){
            output.write(data,0, length);
            System.out.println(data);
        }

--PrintWriter

如：

PrintWriter w2=new PrintWriter("OutputStreamWriter2");

PrintWriter w3=  new PrintWriter(  
                new OutputStreamWriter(  
                       new FileOutputStream("OutputStreamWriter2"),"UTF-8"));

URL 读写

public void test(){
        String boundary = "--------httppost123";
        try {
            URL url=new URL("http://www.baidu.com/");
            //    Proxy proxy = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("10.100.201.236", 8080)); //代理
            HttpURLConnection connection=(HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.setUseCaches(false);
            connection.setConnectTimeout(40000); // 连接超时为10秒
            connection.setRequestMethod("POST");
            connection.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + boundary);
            connection.connect();
            InputStream in = connection.getInputStream();
            BufferedInputStream input=new BufferedInputStream(in);
            OutputStream out=new FileOutputStream("baidu");     
            BufferedOutputStream out2=new BufferedOutputStream(out);
            byte[] buffer = new byte[1024];
            for (int k=0;(k = input.read(buffer)) != -1;) {
                out2.write(buffer, 0, k);
            }
            connection.disconnect();
            System.out.println(new String(out.toByteArray()));
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }