使用指定编码读取文件

public static String toString(File file, String charset){
        StringBuilder result = new StringBuilder();
        BufferedReader br = null;
        try{
        	br=new BufferedReader(new InputStreamReader(new FileInputStream(file), charset));//构造一个BufferedReader类来读取文件
            String s = null;
            while((s = br.readLine())!=null){//使用readLine方法，一次读一行
                result.append(System.lineSeparator()+s);
            }
        }catch(Exception e){
            e.printStackTrace();
        } finally {
        	if (br != null) {
        		try {
					br.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
        	}
		}
        return result.toString();
    }