Android/java 读写文件

读内存卡的文件

读取图片，视频等媒体文件byte流，

public static byte[] readStream(String imagepath) throws Exception {
		FileInputStream fs = new FileInputStream(imagepath);
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		byte[] buffer = new byte[1024];
		int len = 0;
		while (-1 != (len = fs.read(buffer))) {
			outStream.write(buffer, 0, len);
		}
		outStream.close();
		fs.close();
		return outStream.toByteArray();
	}

读取文本文件，用Strng保存

	public String readFile(String filename)
	{
	   String content = null;
	   File file = new File(filename); //for ex foo.txt
	   try {
	       FileReader reader = new FileReader(file);
	       char[] chars = new char[(int) file.length()];
	       reader.read(chars);
	       content = new String(chars);
	       reader.close();
	   } catch (IOException e) {
	       e.printStackTrace();
	   }
	   return content;
	}

写图片，视频等媒体文件，必须用byte[]来写

	public void writeFile(String filePath,byte[] f){
		try {
			FileOutputStream out = new FileOutputStream(new File(filePath));
			out.write(f);
			out.close();
		} catch (IOException e) {
			e.printStackTrace();
		}

       
	}

写文本文件，写log信息都可以

	public void writeFile(String filePath,String f){
		FileWriter fw;
		try {
			fw = new FileWriter(filePath);
			fw.write(f);
			fw.close();
		} catch (IOException e) {
			e.printStackTrace();
		}

       
	}