Java Read/Write File

Read File

private String readFile(String fileName, String fileCharacter)

{

String line = "";

try

{

FileInputStream fis = new FileInputStream(new File(fileName));

// java.io.FileNotFoundException

BufferedReader br =new BufferedReader(new InputStreamReader(fis,fileCharacter));

// java.io.UnsupportedEncodingException

   

// java.io.IOException

while(br.ready())

line += br.readLine();

    br.close();

}

catch (FileNotFoundException e)

{

System.out.println(e.getMessage());

}

catch (Exception e)

{

System.out.println(e.getMessage());

}

return line;

}

Write File

private void writeFile(String fileName, byte[] writeText)

{

try

{

// Create file

File file = new File(fileName);

FileOutputStream fout = new FileOutputStream(file);

fout.write(writeText);

fout.close();

}

catch (Exception e)

{

//Catch exception if any

System.err.println("Error: " + e.getMessage());

}

}

編碼轉換

byte[] String.getBytes(characterset);

getBytes() 回傳 string 在該平台的預設編碼的byte array

或者使用者自行指定編碼

ex.

String a = "殺很大";

bytes[] data = a.getBytes("UTF-8");

new String(byte[], characterset);

從byte array產生Unicode字串

若擔心猜錯byte array的編碼

則字行指定 characterset

Java

Install

Download from http://java.sun.com/javase/downloads/index.jsp

Click "Get the JDK download"

Select your Platform

Setting Envrionment Variable

In Windows

• JAVA_HOME
  

C:\Program Files\Java\jdkX.X.X_XX

• CLASSPATH
  

.;%JAVA_HOME%\lib;%JAVA_HOME%\lib\tools.jar;

• PATH

.;%JAVA_HOME%\bin;.............