add java_api()

Author: scivision

+stdlib/cpu_load.m

@@ -9,6 +9,12 @@
 
 b = java.lang.management.ManagementFactory.getOperatingSystemMXBean();
 
-L = b.getSystemCpuLoad(); % deprecated, but Matlab R2023b didn't have getCpuLoad() yet
+if stdlib.java_api() < 14
+  L = b.getSystemCpuLoad();
+else
+  L = b.getCpuLoad();
+end
+
+% https://docs.oracle.com/en/java/javase/21/docs/api/jdk.management/com/sun/management/OperatingSystemMXBean.html#getSystemCpuLoad()
 
 end

+stdlib/ini2struct.m

@@ -32,11 +32,11 @@
   elseif Val(1)==''''                     % single-quoted string
     Val = strtok(Val, '''');
   else
-    Val = strtok(Val, ';');             % remove inline comment
-    Val = strtok(Val, '#');             % remove inline comment
+    Val = strtok(Val, ";");             % remove inline comment
+    Val = strtok(Val, "#");             % remove inline comment
     Val = strtrim(Val);                 % remove spaces before comment
 
-    [val, status] = str2num(Val);
+    [val, status] = double(string(Val));
     if status, Val = val; end           % convert string to number(s)
   end
 

+stdlib/java_api.m

@@ -0,0 +1,14 @@
+function api = java_api()
+
+v = stdlib.java_version();
+
+% major version is first number before "."
+
+a = split(v, ".");
+if a(1) == "1"
+  api = double(a(2));
+else
+  api = double(a(1));
+end
+
+end

+stdlib/java_version.m

@@ -2,6 +2,9 @@
 % get version of Java Virtual Machine
   v = string(java.lang.System.getProperty("java.version"));
 
+% this gives a long string with more detail
+% version("-java")
+
 % these give the Matlab version, not the JVM version.
 % java.lang.Runtime.version()
 % java.lang.Runtime.getRuntime().version

+stdlib/ram_total.m

@@ -1,15 +1,15 @@
 function bytes = ram_total()
 %% ram_total()
 % get total physical RAM across operating systems
-% https://docs.oracle.com/en/java/javase/21/docs/api/jdk.management/com/sun/management/OperatingSystemMXBean.html#getTotalMemorySize()
+% https://docs.oracle.com/en/java/javase/21/docs/api/jdk.management/com/sun/management/OperatingSystemMXBean.html#getTotalPhysicalMemorySize()
 %
 %%% Outputs
 % * bytes: total physical RAM [bytes]
 
-import java.lang.management.ManagementFactory
-
-b = ManagementFactory.getOperatingSystemMXBean();
+b = java.lang.management.ManagementFactory.getOperatingSystemMXBean();
 
-bytes = b.getTotalPhysicalMemorySize(); % deprecated but Matlab R2023b doesn't have getPhysicalMemorySize() yet
+bytes = b.getTotalPhysicalMemorySize();
+% deprecated but Matlab doesn't have Java 14 getPhysicalMemorySize() yet
+% https://docs.oracle.com/en/java/javase/21/docs/api/jdk.management/com/sun/management/OperatingSystemMXBean.html#getTotalMemorySize()
 
 end

+stdlib/version_atleast.m

@@ -12,8 +12,8 @@
 % r: logical
 
 arguments
-    in (1,1) string
-    ref (1,1) string
+  in (1,1) string
+  ref (1,1) string
 end
 
 in = split(in, ' ');

Readme.md

@@ -17,7 +17,7 @@ buildtool
 
 [API Documentation](https://geospace-code.github.io/matlab-stdlib)
 
-## Developer notes
+## Java details
 
 The "matlab-stdlib" package uses Java functions throughout, with the higher-level
 [java.nio.Files](https://docs.oracle.com/en/java/javase/22/docs/api/java.base/java/nio/file/Files.html)
@@ -28,6 +28,24 @@ That is, if Matlab was started with
 [-nojvm](https://www.mathworks.com/help/matlab/matlab_env/commonly-used-startup-options.html),
 many of the stdlib filesystem function do not work.
 
+Get the JVM version with
+
+```matlab
+version("-java")
+```
+
+The Matlab default
+[JVM can be configured](https://www.mathworks.com/help/matlab/matlab_external/configure-your-system-to-use-java.html)
+to
+[compatible JRE](https://www.mathworks.com/support/requirements/language-interfaces.html)
+across
+[Matlab versions](https://www.mathworks.com/support/requirements/openjdk.html)
+by using the
+[jenv](https://www.mathworks.com/help/matlab/ref/jenv.html)
+Matlab function.
+
+Matlab-stdlib has been test with JVM from version 8 to 17.
+
 ## Acknowledgements
 
 Stdlib for Matlab was partly funded by NASA NNH19ZDA001N-HDEE grant 80NSSC20K0176.