回音壁

这几天读写文件的操作比较多，就写个帮助类，把打开关闭文件的代码拿出来，现在常用的是 BufferedReader 和 PrintWriter，以后用别的时再加。

import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;

public class FileHelper {
/**
 * 读文件时的打开文件
 * 
 * @param path
 *            要打开的文件路径
 * @param charset
 *            要以什么字符集打开文件
 * @return 返回BufferedReader
 */
public static BufferedReader openFileForRead(
	String path, String charset)
		throws Exception {
  if (path == null || path.equals(""))
	return null;
  BufferedReader reader = null;
  try {
    if (charset != null && !charset.equals(""))
        reader = new BufferedReader(
		new InputStreamReader(
	    new FileInputStream(path), charset));
    else
        reader = new BufferedReader(
		new InputStreamReader(
		new FileInputStream(path)));
  } catch (Exception e) {
	e.printStackTrace();
	throw e;
  }
  return reader;
}

public static void closeFileForRead(
	Object reader) {
  if (reader == null)
	return;
  if (reader instanceof BufferedReader) {
	BufferedReader br = 
		(BufferedReader) reader;
	try {
		br.close();
	} catch (Exception e) {
		e.printStackTrace();
	}
  }
}

/**
 * 写文件时的打开文件
 * 
 * @param path
 *            要写的文件路径
 * @param charset
 *            要以什么字符集写入文件
 * @param append
 *            是否追加
 * @return PrintWriter
 */
public static PrintWriter openFileForWrite(
		String path, String charset,
		boolean append) throws Exception {
  if (path == null || path.equals(""))
	return null;
  PrintWriter writer = null;
  try {
    if (charset == null || charset.equals("")) {
	writer = new PrintWriter(
	       new OutputStreamWriter(
	       new FileOutputStream(path, append)));
    } else {
	writer = new PrintWriter(
	   new OutputStreamWriter(
	   new FileOutputStream(path, append)
	   , "UTF-8"));
    }
  } catch (Exception e) {
	e.printStackTrace();
	throw e;
  }

  return writer;
}

public static void closeFileForWrite(
	Object writer){
  if(writer == null)
	return;
  if(writer instanceof PrintWriter){
	PrintWriter pw = (PrintWriter)writer;
	try {
		pw.close();
	} catch (Exception e) {
		e.printStackTrace();
	}
  }
}

public static void main(String[] args) {
  try {
    PrintWriter pw = openFileForWrite(
        "d:/info2.txt", "UTF-8", true);
    pw.println("啊");
    closeFileForWrite(pw);

    BufferedReader br = openFileForRead(
        "d:/info2.txt", "UTF-8");
    echo(br.readLine());
    echo(br.readLine());
    closeFileForRead(br);			
  } catch (Exception e) {
	e.printStackTrace();
  }
}

public static void echo(String str) {
	System.out.println(str);
}

}