java读取json文件的2种方式例子

static String readWithFileInputStream(){
        String jsonString;
                //System.getProperty("user.dir")为获取根目录
                //File.separator为不同操作系统的分隔符，linux和win是不一样的
                //tempFilePath该字符串里面为我们配置文件的路径
               String fileName = "xx_config.json";
//                String tempFilePath = System.getProperty("user.dir") + File.separator + "resource" + File.separator + fileName;
//                System.out.print(tempFilePath);
        StringBuilder sb = new StringBuilder();
                try{
                    InputStream input = new FileInputStream(fileName);
                    byte[] buffer = new byte[1024];
                    int length = 0;
                    length = input.read(buffer);
                    while(length != -1){
                        sb.append(new String(buffer, 0 , length));
                        length = input.read(buffer);
                    }
                }catch (Exception e){
                    e.printStackTrace();
                }
        return    jsonString = sb.toString();
            }

    TargetConfig config = (TargetConfig) JSON.parseObject(jsonString, TargetConfig.class);

    static String readWithClassLoader() throws IOException {
        String fileName = "xx_config.json";
       ClassLoader  classLoader =  TargetConfig.class.getClassLoader();
        BufferedReader reader = null;
            InputStream inputStream = classLoader.getResourceAsStream(fileName);
            reader = new BufferedReader(new InputStreamReader(inputStream));
            StringBuilder content = new StringBuilder();
            String line = reader.readLine();
            while (!StringUtil.isEmpty(line)) {
                content.append(line);
                line = reader.readLine();
            }
            return content.toString();
    }

    TargetConfig config = (TargetConfig) JSON.parseObject(jsonString, TargetConfig.class);