Disable JVM logging

Closes #118

Signed-off-by: David Thompson <davthomp@redhat.com>

Author: datho7561

package.json

@@ -84,8 +84,8 @@
             "string",
             "null"
           ],
-          "default": "-Xmx64M -XX:+UseG1GC -XX:+UseStringDeduplication",
-          "description": "Specifies extra VM arguments used to launch the MicroProfile Language Server. Eg. use `-Xmx1G  -XX:+UseG1GC -XX:+UseStringDeduplication` to bypass class verification, increase the heap size to 1GB and enable String deduplication with the G1 Garbage collector.",
+          "default": "-Xmx64M -XX:+UseG1GC -XX:+UseStringDeduplication -Xlog:disable",
+          "description": "Specifies extra VM arguments used to launch the MicroProfile Language Server. Eg. use `-Xmx1G  -XX:+UseG1GC -XX:+UseStringDeduplication` to increase the heap size to 1GB and enable String deduplication with the G1 Garbage collector.",
           "scope": "window"
         },
         "microprofile.tools.trace.server": {

src/languageServer/javaServerStarter.ts

@@ -37,6 +37,12 @@ function prepareParams(microprofileJavaExtensions: string[]): string[] {
       params.push(watchParentProcess + 'false');
     }
   }
+  // Disable logging unless the user specifically sets it to a different value.
+  // Logging can cause issues, since sometimes it writes to standard out.
+  // See https://github.com/redhat-developer/vscode-java/issues/2577.
+  if (vmargs.indexOf("-Xlog:") < 0) {
+    params.push("-Xlog:disable");
+  }
   parseVMargs(params, vmargs);
   const serverHome: string = path.resolve(__dirname, '../server');
   const microprofileServerFound: Array<string> = glob.sync(`**/${MICROPROFILE_SERVER_NAME}`, { cwd: serverHome });