android读去txt 为string

直接用字节流读取，可保留原格式，在拼装字符串的时候可以把编码转为utf－8 防止乱码，但是根据缓存byte数组的大小不同，会出现部分字符乱码情况

public static String readToText(String filePath) {//按字节流读取可保留原格式，但是有部分乱码情况，根据每次读取的byte数组大小而变化
        StringBuffer txtContent = new StringBuffer();
        byte[] b = new byte[2048];
        InputStream in = null;
        try {
            in = new FileInputStream(filePath);
            int n;
            while ((n = in.read(b)) != -1) {
                txtContent.append(new String(b, 0, n, "utf-8"));
            }
            in.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (in != null) {
                try {
                    in.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return txtContent.toString();
    }

使用字符流的readline读取出来不能保留文档原格式，里面的空格换行都失效了。但是没有乱码。最终解决办法，是采用此方法，然后手动拼接换行符。代码如下：

public static String readtxt(String path) {//按行读取，不能保留换行等格式，所以需要手动添加每行换行符。
//        String result = "";
        StringBuffer txtContent = new StringBuffer();
        File file = new File(path);
        try {
            int len = 0;
            FileInputStream in = new FileInputStream(file);
            InputStreamReader reader = new InputStreamReader(in, "utf-8");
            BufferedReader br = new BufferedReader(reader);
            String s = null;
            while ((s = br.readLine()) != null) {
                if (len != 0) {// 处理换行符的问题，第一行不换行
                    txtContent.append(new String(("\r\n" + s).getBytes(), "utf-8"));
                } else {
                    txtContent.append(new String(s.getBytes(), "utf-8"));
                }
                len++;
            }
            reader.close();
            in.close();
        } catch (UnsupportedEncodingException | FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    /*try {
        BufferedReader br = new BufferedReader(new FileReader(new File(path)));
        String s = null;
        while((s=br.readLine())!=null){
            result = result + "\n" + s;
        }
    } catch (FileNotFoundException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }*/
        return txtContent.toString();
    }