如何将接收字节数组作为base64转换为字符串并写入Jmeter中的文件

Question

{"result":{"success":true,"errMsg":"error"},"bytes":"PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0idXRmLTgiPz4NCjxCdXNpbmVzc1J1bGUgeG1sbnM6eHNpPSJodHRwOi8vd3d3LnczLm9yZy8yMDAxL1hNTFNjaGVtYS1pbnN0YW5jZSIgeG1sbnM6eHNkPSJodHRwOi8vd3d3LnczLm9yZy8yMDAxL1hNTFNjaGVtYSI+DQogICAgPEN"}

我收到类似上面的响应，我需要将字节转换为字符串并使用 Jmeter 写入文件，这怎么可能，我能够使用 JSON 提取器提取值并写入文件来写入文件

receivedbytes =  vars.get("recvBytes");
log.info(receivedbytes);
FileWriter fstream = new FileWriter("C:\\tmp\\getSoftwarePackage.out", true);
BufferedWriter out = new BufferedWriter(fstream);
out.write(receivedbytes);
out.close();
fstream.close();

recvBytes 是响应字节数

Answer 1

解码后就可以实现了。

import org.apache.commons.codec.binary.Base64; String receivedbytes = 

vars.get("recvBytes"); 
log.info(receivedbytes); 
log.info("Decoding base64 format");
String decoded_response = new String(Base64.decodeBase64(receivedbytes));
FileWriter fstream = new FileWriter("C:\\tmp\\getSoftwarePackage.out", true);
BufferedWriter out = new BufferedWriter(fstream);
out.write(decoded_response); 
out.close(); 
fstream.close();

Answer 2

1. Since JMeter 3.1 you should be using JSR223 Test Elements and Groovy language，不是 Beanshell
2. 您收到的不是字节数组，而是 Base64 字符串
3. 如果您要使用多个线程编写同一个文件，您将遇到race condition 导致数据丢失

假设以上所有：

1. 将您的代码修改为如下所示：

   vars.put('decodedBytes', new String(vars.get('recvBytes').decodeBase64()))
   

2. 将下一行添加到user.properties file:

   sample_variables=decodedBytes
   

3. 使用Flexible File Writer将变量写入文件

如果您不“害怕”竞态条件或使用 JMeter 进行功能测试，以 1 个虚拟用户运行它，您可以修改代码如下：

new File('C:\\tmp\\getSoftwarePackage.out').text = new String(vars.get('recvBytes').decodeBase64())