Java 基础 inputStream.read(bufferBytes) 读取文本错乱、异常、不全

...
 byte[] bufferBytes = new byte[1024];
        StringBuffer stringBuilder = new StringBuffer();
        try {
            int length = 0;
            while ((length = inputStream.read(bufferBytes)) != -1) {
                stringBuilder.append(new String(bufferBytes));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
     ...

之前读小文件没啥问题，就这么用了，今天读json文件比较大的在读取的时候出现问题了

原因：因为每次 while 循环后 bufferBytes 不会清空，仍然会存在缓存上一次的数据，如果直接 bufferBytes 整个拿来 append 用，数据就错乱了，所以必须要拿每次真实读到的内容进行使用，或者套一层 BufferedReader 进行处理

• 方法1：append 时候紧跟上指定长度

...
 byte[] bufferBytes = new byte[1024];
        StringBuffer stringBuilder = new StringBuffer();
        try {
            int length = 0;
            while ((length = inputStream.read(bufferBytes)) != -1) {
                stringBuilder.append(new String(bufferBytes, 0, length));
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
     ...

• 方法二：采用 bufferedReader.readLine 方式去读

try {
            fileInputStream = new FileInputStream(file);
            inputStreamReader = new InputStreamReader(fileInputStream);
            bufReader = new BufferedReader(inputStreamReader);
            String line = "";
            while ((line = bufReader.readLine()) != null) {
                stringBuilder.append(line);
            }
        } catch (IOException e) {
            e.printStackTrace();
           
        }