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In order to improve readability (Why readability matters) here are some code style guidelines for the JMeter project.

Java

We now enforce many of these rules, and more using checkstyle.

Indentation/White space

4 spaces for indentation
- No tabs
"Soft" maximum line length of ~80 characters
- Editors and monitors used by most programmers with good eyes can easily handle 120 characters. However:
  - lines longer than this can be harder to read and frustrating work with
  - not all programmers have good eyes and/or wide high resolution monitors
  - in typography line length is recommended to be 45-75 with the optimum being 66 or 45-90
- Here is an example from UrlConfigGui.java
  - which do you find easier to read?
    element.setProperty(HTTPSamplerBase.BROWSER_COMPATIBLE_MULTIPART, useBrowserCompatibleMultipartMode.isSelected(),HTTPSamplerBase.BROWSER_COMPATIBLE_MULTIPART_MODE_DEFAULT);
    or
    element.setProperty( HTTPSamplerBase.BROWSER_COMPATIBLE_MULTIPART, useBrowserCompatibleMultipartMode.isSelected(), HTTPSamplerBase.BROWSER_COMPATIBLE_MULTIPART_MODE_DEFAULT);

"Hard" maximum line length of 120 characters
- Except for imports or other places where breaking the line wouldn't aid readability

Spacing

Spacing between elements on a line e.g.
- if (x | y) {
- while (true) {
- methodCall(arg1, arg2) {
- String s = "con" + "cat";
Braces are always used with if, else, for, do and while statements, even if the body is empty or only a single statement

JavaDoc

Parameter descriptions are aligned and not on new lines.
No invalid tags
No tags without a description
Blank line after main description but not after any tags

Other

Import order
- java, javax, org, net, com, others
Import spacing
- line break between each group
No wildcard (.*) imports
Method line length (soft limit of 50)
Class line length (soft limit of 500)

Java 8 Specific

Use of Optional
- Return types where null is possible (which aren't performance critical)
Default/static methods on Interfaces
Utilise lambdas where possible (max ~5 lines)
- If the lambda is >3 line then consider making this a separate method

See Also