Streaming in java

gistfile1.txt

Simple java program to read from files using FileReader

- reading from a file using FileReader 

```java
File file=null;  
FileReader fileReader=null;  
StringBuilder sb=new StringBuilder();  
try {  
     file = new File("src/main/java/com/vksviit/patterns/factorydesignpattern/streaming/sample.txt");  
    fileReader = new FileReader(file);  
    int currentChar=0;  
  
    while(  (currentChar=fileReader.read())!=-1) {  
            char ch = (char)currentChar;  
            sb.append(ch);  
  
    }  
  
    System.out.println(sb);  
  
}catch (IOException e) {  
    e.printStackTrace();  
} finally {  
  
    if (fileReader!=null) {  
        fileReader.close();  
    }  
}
```
### 2. Simple java program to read from files using BufferedReader 

```java
try {  
    System.out.println("reading from sameple 3 ");  
    bufferedReader = new BufferedReader( new InputStreamReader( new FileInputStream(("src/main/java/com/vksviit/patterns/factorydesignpattern/streaming/sample3.txt"))) );  
    String currentLine;  
    while(  (currentLine =bufferedReader.readLine())!=null) {  
        System.out.println(currentLine);  
    }  
  
}catch (IOException e) {  
    e.printStackTrace();  
  
} finally {  
  
    if(bufferedReader!=null) {  
        bufferedReader.close();  
    }  
}  
  
  
System.out.println("reading from BufferedReader Ended ...");
```


### 3. Read from a file and write to another file using BufferedReader and BufferedWriter

```java
  
try (BufferedReader reader4 = new BufferedReader(new InputStreamReader(new FileInputStream("src/main/java/com/vksviit/patterns/factorydesignpattern/streaming/sample4.txt")), 16384);  
     BufferedWriter writer4 = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("src/main/java/com/vksviit/patterns/factorydesignpattern/streaming/sample5.txt")), 16384)) {  
  
    String currentLine;  
    while ((currentLine = reader4.readLine()) != null) {  
        System.out.println(currentLine);  
        writer4.write(currentLine);  
        writer4.write("\n");  
    }  
  
  
} catch (Exception e) {  
    e.printStackTrace();  
  
}
```



### 4. Read from a file and create chunks of size 1000 and store it in the disk 

```java
BufferedReader bufferedReader2=null;  
BufferedWriter bufferedWriter2 = null;  
  
try{  
  
    bufferedReader2= new BufferedReader(new InputStreamReader(new FileInputStream("src/main/java/com/vksviit/patterns/factorydesignpattern/streaming/sample6.txt"), StandardCharsets.UTF_8));  
  
    String currentString;  
    int count=0;  
    while ((currentString = bufferedReader2.readLine())!=null) {  
  
        if (count++ %10==0) {  
            //create new file  
           if (bufferedWriter2!=null) {  
               bufferedWriter2.close();  
           }  
  
            System.out.println("count is  :  " +count);  
            bufferedWriter2 = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("src/main/java/com/vksviit/patterns/factorydesignpattern/streaming/chunks/smallChunk" + (count/10) +".txt"  ),StandardCharsets.UTF_8));  
            System.out.println("chunk name is :   "+ "smallChunk" +(count/10));  
        }  
        bufferedWriter2.write(currentString);  
        bufferedWriter2.newLine();  
  
    }  
  
  
  
  
}catch (Exception e) {  
    e.printStackTrace();  
}finally {  
    if (bufferedReader2!=null) {  
  
        bufferedReader2.close();  
    }  
    if (bufferedWriter2!=null) {  
        bufferedWriter2.close();  
    }  
  
}
```


### 5. InputStream from an HTTPS Connection and Printing Server Certificates

```java
package com.vksviit.patterns.factorydesignpattern.streaming;  
  
import javax.net.ssl.HttpsURLConnection;  
import java.io.BufferedReader;  
import java.io.IOException;  
import java.io.InputStreamReader;  
import java.net.URL;  
import java.net.URLConnection;  
import java.security.cert.Certificate;  
  
public class HttpConnectionReaders {  
  
  
        public static void main(String[] args) throws Exception {  
  
            URL yahooUrl = new URL("https://www.google.com/");  
  
            HttpsURLConnection connection = (HttpsURLConnection)yahooUrl.openConnection();  
            //print the content  
            print_content(connection);  
            print_certificates(connection);  
  
  
        }  
  
        public  static  void print_content(HttpsURLConnection connection) throws IOException {  
  
            BufferedReader bufferedReader = null;  
            try {  
                bufferedReader = new BufferedReader(new InputStreamReader(connection.getInputStream()));  
                String inputLine;  
                int counter=0;  
                while ((inputLine = bufferedReader.readLine()) != null) {  
                    System.out.println(counter++);  
//                    System.out.println(inputLine);  
  
                }  
            } catch (IOException e) {  
                throw new RuntimeException(e);  
            }  
  
        }  
  
        public static void print_certificates(HttpsURLConnection connection) {  
  
            if (connection != null) {  
                try{  
                    int responseCode = connection.getResponseCode();  
                    System.out.println("responseCode is " +responseCode);  
  
                    Certificate[] certificate = connection.getServerCertificates();  
  
                    for (Certificate cert :certificate) {  
  
                        // what is certificate type x.509 and Algorithm EC and RSA Ceritifactae Format X.509  
                        System.out.println("Certificate Type :  " + cert.getType());  
                        System.out.println("Certificate Algorithm :  " + cert.getPublicKey().getAlgorithm());  
                        System.out.println("Certificate format  :  " + cert.getPublicKey().getFormat());  
  
  
                    }  
  
                }catch (IOException exception) {  
                    exception.printStackTrace();  
                }  
  
            }  
  
  
        }  
    }
```