package cn.felay.io;

import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

/**
 * @author <a mailto:felayman@163.com>felayman</a>
 * @timer 2014年6月10日 下午3:46:19
 */
public class InputStreamDemo {
	/**
	 * 关闭输入流
	 * 
	 * @param in
	 */
	public void freeInputStream(InputStream in) {
		try {
			in.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}

	/**
	 * 获取输入流
	 * 
	 * @param fileName
	 * @return
	 */
	public InputStream getInputStream(String fileName) {
		InputStream in = null;
		try {
			in = new FileInputStream(fileName);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
		return in;
	}

	/**
	 * 从指定的文件中获取内容
	 * 
	 * @param fileName
	 * @return
	 */
	public String getContentFromFile(String fileName) {

		InputStream in = this.getInputStream(fileName);
		byte[] b = new byte[1024];
		try {
			while (in.read(b) != -1) {
			}
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			this.freeInputStream(in);
		}
		String content = new String(b);
		content = content.trim();
		return content;
	}

	/**
	 * 获取文件中字节长度
	 * 
	 * @param fileName
	 * @return
	 */
	public int getLenFromFile(String fileName) {
		InputStream in = null;
		int len = 0;
		try {
			in = new FileInputStream(fileName);
			len = in.available();
		} catch (FileNotFoundException e) {
			System.out.println(e.getLocalizedMessage());
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				in.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return len;
	}

	/**
	 * 从字节数组中获取字节长度
	 * 
	 * @param b
	 * @return
	 */
	public int getLenFromByte(byte[] b) {
		InputStream in = null;
		in = new ByteArrayInputStream(b);
		int len = 0;
		try {
			len = in.available();
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try {
				in.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		return len;
	}

	public byte[] getContentFromString(String str) {
		byte[] b = str.getBytes();
		return b;
	}

	public static void main(String[] args) {
		// 获取文件中字节长度
		InputStreamDemo isd = new InputStreamDemo();
		String fileName = "src/res/test1.text";
		int fileLen = isd.getLenFromFile(fileName);
		System.out.println("文件长度为:" + fileLen);
		// 从指定文件获取内容
		String content = isd.getContentFromFile(fileName);
		System.out.println("获取的内容为:" + content);
	}

}