added logging module to server

src/main/java/JobServ/JobServServer.java

@@ -29,7 +29,7 @@ import java.util.logging.Logger;
  * Which accepts incoming connections from client.
  */
 public class JobServServer {
-    private static final Logger logger = Logger.getLogger(JobServServer.class.getName());
+    public static SimpleLogger logger = new SimpleLogger("JobServ-Server-");
 
     private Server server;
     private ProcessManager manager;
@@ -54,12 +54,12 @@ public class JobServServer {
     private void start() throws IOException {
         // TODO: this should be passed in from a configuration manager
         server.start();
-        logger.info("Server initialized!");
+        logger.write("Server initialized!");
 
         Runtime.getRuntime().addShutdownHook(new Thread() {
                 @Override
                 public void run() {
-                    logger.info("Shutting down server");
+                    logger.write("Shutting down server");
                     manager.shutdown();
                     JobServServer.this.stop();
                 }
@@ -125,7 +125,7 @@ public class JobServServer {
 	          return;
 	      }
 
-        System.out.println("JobServ Server Initialized! Connect anytime...");
+        JobServServer.logger.write("Initialized JobServ Server");
         server.blockUntilShutdown();
     }
 }

src/main/java/JobServ/ProcessController.java

@@ -131,7 +131,7 @@ class ProcessController {
      */
     public void kill() {
         if (this.killedManually) {
-            System.err.println("[~] Tried to kill already killed process");
+            JobServServer.logger.write("Tried to kill already killed process");
             return;
         }
 
@@ -143,7 +143,8 @@ class ProcessController {
             this.process.destroy();
             this.killedManually = true;
         } catch (IOException e) {
-            System.err.println("[-] Killing process failed: " + e.getMessage());
+            JobServServer.logger.write("Killing process " +
+                                       String.valueOf(this.pid) + " failed: " + e.getMessage());
         }
     }
 }

src/main/java/JobServ/ProcessManager.java

@@ -77,7 +77,8 @@ class ProcessManager {
             return newProc.getPid();
 
         } catch (IOException e) {
-            System.err.println("Couldnt Spawn New Command: " + e.getMessage());
+            JobServServer.logger.write("Couldnt Spawn New Command: (" +
+                                       command + "): " + e.getMessage());
             return -1;
         }
     }
@@ -99,7 +100,8 @@ class ProcessManager {
 
         } catch (TimeoutException e) {
             // lock could not be grabbed before timeout
-            System.err.println("Timeout getting process status: " + e.getMessage());
+            JobServServer.logger.write("Timeout getting process " +
+                                       String.valueOf(pid) + " status: " + e.getMessage());
             return 4;
         }
 
@@ -125,7 +127,8 @@ class ProcessManager {
             }
 
         } catch (TimeoutException e) {
-            System.err.println("Timeout getting process return: " + e.getMessage());
+            JobServServer.logger.write("Timeout getting process " +
+                                       String.valueOf(pid) + " return: " + e.getMessage());
             return 259;
         }
 
@@ -147,7 +150,8 @@ class ProcessManager {
             }
 
         } catch (TimeoutException e) {
-            System.err.println("Timeout getting process output: " + e.getMessage());
+            JobServServer.logger.write("Timeout getting process " +
+                                       String.valueOf(pid) + " output: " + e.getMessage());
             return "[-] SERVER: Timeout grabbing lock to access process information";
         }
 
@@ -172,7 +176,8 @@ class ProcessManager {
             }
 
         } catch (TimeoutException e) {
-            System.err.println("Timeout killing process: " + e.getMessage());
+            JobServServer.logger.write("Timeout killing process " +
+                                       String.valueOf(pid) + ": " + e.getMessage());
             return 3;
         }
 
@@ -213,12 +218,14 @@ class ProcessManager {
             future.get(this.LOCK_TIMEOUT, TimeUnit.SECONDS);
 
         } catch (InterruptedException e) {
-            System.err.println("[!] ERROR: " + e.getMessage());
+            JobServServer.logger.write("[!] Couldnt get lock " +
+                                       String.valueOf(pid) + ": "+ e.getMessage());
             future.cancel(true);
             return false;
 
         } catch (ExecutionException e) {
-            System.err.println("[!] ERROR: " + e.getMessage());
+            JobServServer.logger.write("[!] Couldnt get lock " +
+                                       String.valueOf(pid) + ": "+ e.getMessage());
             future.cancel(true);
             return false;
 

src/main/java/JobServ/SimpleLogger.java

@@ -0,0 +1,84 @@
+/*
+ * SimpleLogger
+ *
+ * v1.0
+ *
+ * May 26, 2019
+ */
+
+package JobServ;
+
+import java.io.File;
+import java.sql.Timestamp;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.text.SimpleDateFormat;
+
+/*
+ * SimpleLogger
+ * Automatically manages the creation of and output to a log file
+ * TODO: Log Levels, decorations for entries of different severity
+ */
+class SimpleLogger {
+    private static final SimpleDateFormat dateTimeFormat = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss");
+    private Timestamp programStart;
+    private FileWriter logWriter;
+    private Boolean writable = true;
+
+    /*
+     * Constructor
+     * Initializes timestamp and opens new file for logging
+     */
+    public SimpleLogger(String filePrefix) {
+        this.programStart = new Timestamp(System.currentTimeMillis());
+        File currentLog = new File(filePrefix + this.dateTimeFormat.format(this.programStart));
+
+        try{
+            this.logWriter = new FileWriter(currentLog, true);
+
+        } catch (IOException e) {
+            System.out.println("Error creating LogWriter!");
+            this.writable = false;
+        }
+
+        this.write(this.programStart.toString() + ": JobServ Logging Started");
+    }
+
+    /*
+     * write
+     * appends a line of information to the log
+     */
+    public void write(String message) {
+        Timestamp currentTime = new Timestamp(System.currentTimeMillis());
+        message = currentTime.toString() + "> " + message;
+
+        if (this.writable) {
+            try {
+                this.logWriter.write(message);
+
+            } catch (IOException e) {
+                System.out.println(e.getMessage());
+                this.writable = false;
+            }
+        }
+
+        System.out.println(message);
+    }
+
+    /*
+     * shutdown()
+     * called on server exit, closes the FileWriter and frees its resources
+     */
+    public void shutdown() {
+        Timestamp exitTime = new Timestamp(System.currentTimeMillis());
+        this.write(exitTime.toString() + ": JobServ Logging Stopped");
+
+        try {
+            this.logWriter.close();
+
+        } catch (IOException e) {
+            // not sure what would be appropriate to do here
+            System.out.println(e.getMessage());
+        }
+    }
+}