前提：
1、想要知道所有的接口的请求和返回数据
2、一般是在做接口自动化时，起到问题更好追踪的作用。
3、一般在性能测试时，建议关闭该配置，因为在执行时写很多数据，会严重影响性能。
配置：
打开jmeter中的配置文件【jmeter.properties】或者【user.properties】
修改里面的save内容：
# legitimate values: xml, csv, db. Only xml and csv are currently supported.
#jmeter.save.saveservice.output_format=csv
jmeter.save.saveservice.output_format=xml
# true when field should be saved; false otherwise
# assertion_results_failure_message only affects CSV output
jmeter.save.saveservice.assertion_results_failure_message=true
#
# legitimate values: none, first, all
#jmeter.save.saveservice.assertion_results=none
#
jmeter.save.saveservice.data_type=true
jmeter.save.saveservice.label=true
jmeter.save.saveservice.response_code=true
# response_data is not currently supported for CSV output
jmeter.save.saveservice.response_data=true
# Save ResponseData for failed samples
jmeter.save.saveservice.response_data.on_error=true
jmeter.save.saveservice.response_message=true
jmeter.save.saveservice.successful=true
jmeter.save.saveservice.thread_name=true
jmeter.save.saveservice.time=true
jmeter.save.saveservice.subresults=true
jmeter.save.saveservice.assertions=true
jmeter.save.saveservice.latency=true
# Only available with HttpClient4
jmeter.save.saveservice.connect_time=true
jmeter.save.saveservice.samplerData=true
jmeter.save.saveservice.responseHeaders=true
jmeter.save.saveservice.requestHeaders=true
jmeter.save.saveservice.encoding=true
jmeter.save.saveservice.bytes=true
# Only available with HttpClient4
jmeter.save.saveservice.sent_bytes=true
jmeter.save.saveservice.url=true
jmeter.save.saveservice.filename=true
jmeter.save.saveservice.hostname=true
jmeter.save.saveservice.thread_counts=true
jmeter.save.saveservice.sample_count=true
jmeter.save.saveservice.idle_time=true