Fix eclipse-jdtls#43 support starting the JLS with Java 9

Signed-off-by: Fred Bricon <fbricon@gmail.com>

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## 0.0.5
 * enhancement - configure extra VM arguments in VS Code settings, used to launch the Java Language Server. See [#25](https://github.com/redhat-developer/vscode-java/issues/25). 
 * enhancement - configure java.home property in VS Code settings. See [#28](https://github.com/redhat-developer/vscode-java/issues/28). 
+* enhancement - support running the Java Language Server with Java 9. See [#43](https://github.com/redhat-developer/vscode-java/issues/43). 
 
 ## 0.0.4 (September 26, 2016)
 * enhancement - improved Javadoc/Markdown formatting. See [#13](https://github.com/redhat-developer/vscode-java/issues/13). 

src/extension.ts

@@ -44,7 +44,7 @@ function runJavaServer(){
 				params.push('-Dlog.protocol=true');
 				params.push('-Dlog.level=ALL');
 			}
-		
+
 			params.push('-jar'); params.push(path.resolve( __dirname ,'../../server/plugins/org.eclipse.equinox.launcher_1.3.200.v20160318-1642.jar'));
 			//select configuration directory according to OS
 			let configDir = 'config_win';
@@ -55,6 +55,9 @@ function runJavaServer(){
 			}
 			params.push('-configuration'); params.push(path.resolve( __dirname ,'../../server',configDir));
 			params.push('-data'); params.push(workspacePath);
+			if (requirements.java_version > 8) {
+				params.push('--add-modules=java.se.ee');
+			}
 
 			let vmargs = workspace.getConfiguration("java").get("jdt.ls.vmargs","");
 			parseVMargs(params, vmargs);

src/requirements.ts

@@ -12,6 +12,7 @@ const findJavaHome = require('find-java-home');
 
 interface RequirementsData {
     java_home: string
+    java_version: number
 }
 
 interface ErrorData {
@@ -29,9 +30,9 @@ interface ErrorData {
  */
 export async function resolveRequirements(): Promise<RequirementsData> {
     let java_home = await checkJavaRuntime();
-    let isJava8 = await checkJavaVersion(java_home);
+    let javaVersion = await checkJavaVersion(java_home);
     let serverInstalled = await checkServerInstalled();
-    return Promise.resolve({ "java_home": java_home });
+    return Promise.resolve({ "java_home": java_home, "java_version":javaVersion});
 }
 
 async function checkJavaRuntime(): Promise<any> {
@@ -78,10 +79,12 @@ async function checkJavaRuntime(): Promise<any> {
 async function checkJavaVersion(java_home: string): Promise<any> {
     return new Promise((resolve, reject) => {
         let result = cp.execFile(java_home + '/bin/java', ['-version'], {}, (error, stdout, stderr) => {
-            if (stderr.indexOf('1.8') < 0)
-                openJDKDownload(reject, "Java 8 is required to run. Please download and install a JDK 8.");
-            else
-                resolve(true);
+            if (stderr.indexOf('1.8') < 0 && stderr.indexOf('9.') < 0) {
+                openJDKDownload(reject, "Java 8 minimum is required to run. Please download and install the latest JDK.");
+            } else {
+                let version = (stderr.indexOf('1.8') >= 0)?8:9;
+                resolve(version);
+            }
         });
     });
 }