fix: remove usage of platform dependent strlen (#21) (#22)

Fixes #21 and enables the extism java sdk to be used on windows.

Signed-off-by: Thomas Darimont <[email protected]>

Author: thomasdarimont

src/main/java/org/extism/sdk/LibExtism.java

@@ -169,5 +169,4 @@ Pointer extism_function_new(String name,
     Pointer extism_plugin_cancel_handle(Pointer pluginPointer);
     boolean extism_plugin_cancel(Pointer cancelHandle);
     void extism_function_set_namespace(Pointer p, String name);
-    int strlen(Pointer s);
 }

src/main/java/org/extism/sdk/Plugin.java

@@ -42,15 +42,14 @@ public Plugin(byte[] manifestBytes, boolean withWASI, HostFunction[] functions)
                 withWASI,
                 errormsg);
         if (p == null) {
-            if (functions != null)
+            if (functions != null) {
                 for (int i = 0; i < functions.length; i++) {
-                   LibExtism.INSTANCE.extism_function_free(functions[i].pointer);
+                    LibExtism.INSTANCE.extism_function_free(functions[i].pointer);
                 }
-            int errlen = LibExtism.INSTANCE.strlen(errormsg[0]);
-            byte[] msg = new byte[errlen];
-            errormsg[0].read(0, msg, 0, errlen);
+            }
+            String msg = errormsg[0].getString(0);
             LibExtism.INSTANCE.extism_plugin_new_error_free(errormsg[0]);
-            throw new ExtismException(new String(msg));
+            throw new ExtismException(msg);
         }
 
         this.functions = functions;