JDK 13 RFR of JDK-8223178: Improve FileSystems.newFileSystem example with map factory methods

[Joe Darcy]

Hi Alan,

The maximum line length is actually slightly reduced by the proposed patch:

--- a/src/java.base/share/classes/java/nio/file/FileSystems.java Tue Apr 
30 16:11:42 2019 -0700
+++ b/src/java.base/share/classes/java/nio/file/FileSystems.java Wed May 
01 00:12:25 2019 -0700
@@ -252,10 +252,9 @@
       * Suppose there is a provider identified by the scheme {@code 
"memory"}
       * installed:
       * <pre>
-     *   Map<String,String> env = new HashMap<>();
-     *   env.put("capacity", "16G");
-     *   env.put("blockSize", "4k");
-     *   FileSystem fs = 
FileSystems.newFileSystem(URI.create("memory:///?name=logfs"), env);
+     *   FileSystem fs = 
FileSystems.newFileSystem(URI.create("memory:///?name=logfs"),
+ * Map.of("capacity", "16G",
+ * "blockSize", "4k"));
       * </pre>
       *
       * @param   uri

Keeping env to one line also gives a comparably long line length:

--- a/src/java.base/share/classes/java/nio/file/FileSystems.java Tue Apr 
30 16:11:42 2019 -0700
+++ b/src/java.base/share/classes/java/nio/file/FileSystems.java Wed May 
01 09:50:15 2019 -0700
@@ -252,9 +252,7 @@
       * Suppose there is a provider identified by the scheme {@code 
"memory"}
       * installed:
       * <pre>
-     *   Map<String,String> env = new HashMap<>();
-     *   env.put("capacity", "16G");
-     *   env.put("blockSize", "4k");
+     *   Map<String,String> env = Map.of("capacity", "16G", 
"blockSize", "4k");
       *   FileSystem fs = 
FileSystems.newFileSystem(URI.create("memory:///?name=logfs"), env);
       * </pre>
       *
The {"capacity", "16G"} and {"blockSize", "4k"} can be put on different 
lines to provide a stronger visual hint of grouping.

Which of these alternatives do you prefer?

Thanks,

-Joe

On 4/30/2019 11:16 PM, Alan Bateman wrote:
> On 01/05/2019 02:59, Joe Darcy wrote:
>> :
>>
>> --- a/src/java.base/share/classes/java/nio/file/FileSystems.java Tue 
>> Apr 30 16:11:42 2019 -0700
>> +++ b/src/java.base/share/classes/java/nio/file/FileSystems.java Tue 
>> Apr 30 18:52:11 2019 -0700
>> @@ -252,10 +252,9 @@
>>       * Suppose there is a provider identified by the scheme {@code 
>> "memory"}
>>       * installed:
>>       * <pre>
>> -     *   Map<String,String> env = new HashMap<>();
>> -     *   env.put("capacity", "16G");
>> -     *   env.put("blockSize", "4k");
>> -     *   FileSystem fs = 
>> FileSystems.newFileSystem(URI.create("memory:///?name=logfs"), env);
>> +     *   FileSystem fs = 
>> FileSystems.newFileSystem(URI.create("memory:///?name=logfs"),
>> + * Map.of("capacity", "16G",
>> + * "blockSize", "4k"));
> Changing it to use an unmodifable map is good. One nit the really long 
> line in the source will be annoying with future side-by-side diffs. It 
> wouldn't take much from the readability to keep env.
>
> -Alan