在Groovy中执行代码时出现Stream Closed错误，如何排查解决？

Let's break down what's happening and how to resolve this issue.

What's causing the "Stream closed" error? #

While Groovy's withInputStream is supposed to handle opening and closing the stream safely for you, in a Jenkins pipeline context, there are a few likely culprits:

• Incorrect workspace path: If you're using a declarative Jenkins pipeline, using ${WORKSPACE} directly might not resolve properly—you need to reference env.WORKSPACE instead. Even if the error doesn't say "file not found", a malformed path can lead to unexpected stream behavior.
• Jenkins/Groovy compatibility oddities: Sometimes the automatic stream management in withInputStream clashes with Jenkins' sandbox or classloader setup, causing the stream to close before your properties.load() call finishes.
• Premature stream closure: While less likely here, if any underlying code (like a custom plugin) closes the stream early inside the closure, you'll hit this error.

Fixes to try #

Here are a few reliable solutions to get past this error:

1. Ditch withInputStream for explicit stream handling #

Taking full control of opening and closing the stream with a try-finally block avoids any unexpected behavior from Groovy's automatic management:

Properties properties = new Properties()
File propertiesFile = new File("${env.WORKSPACE}/sonar-project.properties")
InputStream inputStream = null

try {
    inputStream = new FileInputStream(propertiesFile)
    properties.load(inputStream)
} catch (IOException e) {
    echo "Oops, failed to load properties: ${e.message}"
    throw e // Let the pipeline fail if this is critical
} finally {
    if (inputStream != null) {
        try {
            inputStream.close()
        } catch (IOException e) {
            echo "Warning: Had trouble closing the stream: ${e.message}"
        }
    }
}

echo properties."sonar.sources"

2. Double-check your workspace path #

First, confirm you're pointing to the right file. Add these debug lines to your pipeline to verify:

def propsFilePath = "${env.WORKSPACE}/sonar-project.properties"
echo "Looking for properties file at: ${propsFilePath}"
echo "File exists? ${new File(propsFilePath).exists()}"
echo "Can read file? ${new File(propsFilePath).canRead()}"

In declarative pipelines, always use env.WORKSPACE—bare ${WORKSPACE} might not resolve correctly.

3. Use Groovy's simpler file reading shortcuts #

Groovy has cleaner ways to load properties without dealing with streams directly. Try this concise approach:

def properties = new File("${env.WORKSPACE}/sonar-project.properties").withReader { reader ->
    new Properties().tap { load(reader) }
}

echo properties."sonar.sources"

Or even more straightforward:

Properties properties = new Properties()
properties.load(new File("${env.WORKSPACE}/sonar-project.properties").newReader())

echo properties."sonar.sources"

Quick additional checks #

• Make sure the Jenkins agent has read permissions for the sonar-project.properties file.
• Ensure the file isn't locked by another process (like a previous build step that didn't release the file handle).

内容的提问来源于stack exchange，提问作者Karl