groovy - 为什么两次访问Groovy进程的getText()都会导致失败？

Question

我正在用Gradle任务运行一些curl代码，我注意到如果我两次访问进程的文本，则第二次访问总是失败。我注意到通过将process.text传递给XlmSlurper()。如果我首先使用printlned process.text，那么它将在崩溃时崩溃；如果我不进行println，则崩溃将起作用。
这是一些说明这种行为的代码。首先是失败的任务版本:

    task hello {
        println "****** HELLO ******"

        def process = ['curl', '-X', 'POST', '-H', 'Accept: Application/xml', '-H', 'Content-Type: application/json', "http://itemid.sea.redacted.com/item_ids", '-d', '{"user":"Y2VxYnVpbGRhZ2VudDpCdTFsZCE=","request":"guid"}'].execute()
        process.waitFor()

        println "err.text"
        println process.err.text

        println "process.text 1 is:"
        println process.text

        println "process.text 2 is:"
        println process.text
    }

执行此命令后，输出为:

****** HELLO ******
err.text
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   141    0    85  100    56   2412   1589 --:--:-- --:--:-- --:--:--  2428

process.text 1 is:
<?xml version="1.0" encoding="utf-8"?><long xmlns="http://redacted.com/">121144</long>
process.text 2 is:
Failed to notify ProjectEvaluationListener.afterEvaluate(), but primary configuration failure takes precedence.
java.lang.IllegalArgumentException: android.compileSdkVersion is missing!
    at com.android.build.gradle.internal.SdkHandler.initTarget(SdkHandler.java:80)
    at com.android.build.gradle.BasePlugin.ensureTargetSetup(BasePlugin.groovy:462)

但是，如果最后两行println行被注释掉，则说明成功:

    task hello {
        println "****** HELLO ******"

        def process = ['curl', '-X', 'POST', '-H', 'Accept: Application/xml', '-H', 'Content-Type: application/json', "http://itemid.sea.redacted.com/item_ids", '-d', '{"user":"Y2VxYnVpbGRhZ2VudDpCdTFsZCE=","request":"guid"}'].execute()
        process.waitFor()

        println "err.text"
        println process.err.text

        println "process.text 1 is:"
        println process.text

      //  println "process.text 2 is:"
      //  println process.text
    }

哪个有输出:

****** HELLO ******
err.text
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   141    0    85  100    56   1977   1303 --:--:-- --:--:-- --:--:--  2023

process.text 1 is:
<?xml version="1.0" encoding="utf-8"?><long xmlns="http://redacted.com/">121145</long>
:help

Welcome to Gradle 2.2.1.

To run a build, run gradlew <task> ...

To see a list of available tasks, run gradlew tasks

To see a list of command-line options, run gradlew --help

BUILD SUCCESSFUL

为什么添加/删除这些最后的println会造成这种差异？

(为什么第二个版本的输出中还有:help ...？)

在两种情况下，我都是使用./gradlew从命令行运行的

如果使用getText()代替text /，则存在相同的问题

Answer 1

您返回的流只能读取一次。将其写到文件或变量中，然后根据需要从该文件/变量中读取多次。