BAEL-654: Java 9 Process API Improvements (#1235)

* code for BAEL-654: Java 9 Process API Improvements

* incorporate review

core-java-9/pom.xml

@@ -21,6 +21,11 @@
             <artifactId>slf4j-api</artifactId>
             <version>${org.slf4j.version}</version>
         </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>${ch.qos.logback.version}</version>
+        </dependency>
 
         <dependency>
             <groupId>org.hamcrest</groupId>
@@ -76,9 +81,9 @@
     
         <!-- logging -->
         <org.slf4j.version>1.7.21</org.slf4j.version>
-
+        <ch.qos.logback.version>1.2.1</ch.qos.logback.version>
         <!-- maven plugins -->
-        <maven-compiler-plugin.version>3.6-jigsaw-SNAPSHOT</maven-compiler-plugin.version>
+        <maven-compiler-plugin.version>3.6.0</maven-compiler-plugin.version>
         <maven-surefire-plugin.version>2.19.1</maven-surefire-plugin.version>
 
         <!-- testing -->

core-java-9/src/test/java/com/baeldung/java9/process/ProcessAPIEnhancementsTest.java

@@ -0,0 +1,133 @@
+package com.baeldung.java9.process;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+import java.util.stream.Stream;
+
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Created by sanaulla on 2/23/2017.
+ */
+
+public class ProcessAPIEnhancementsTest {
+
+    Logger log = LoggerFactory.getLogger(ProcessAPIEnhancementsTest.class);
+
+    @Test
+    public void givenCurrentProcess_whenInvokeGetInfo_thenSuccess() throws IOException {
+        ProcessHandle processHandle = ProcessHandle.current();
+        ProcessHandle.Info processInfo = processHandle.info();
+        assertNotNull(processHandle.getPid());
+        assertEquals(false, processInfo.arguments()
+          .isPresent());
+        assertEquals(true, processInfo.command()
+          .isPresent());
+        assertTrue(processInfo.command()
+          .get()
+          .contains("java"));
+
+        assertEquals(true, processInfo.startInstant()
+          .isPresent());
+        assertEquals(true, processInfo.totalCpuDuration()
+          .isPresent());
+        assertEquals(true, processInfo.user()
+          .isPresent());
+    }
+
+    @Test
+    public void givenSpawnProcess_whenInvokeGetInfo_thenSuccess() throws IOException {
+
+        String javaCmd = ProcessUtils.getJavaCmd()
+          .getAbsolutePath();
+        ProcessBuilder processBuilder = new ProcessBuilder(javaCmd, "-version");
+        Process process = processBuilder.inheritIO()
+          .start();
+        ProcessHandle processHandle = process.toHandle();
+        ProcessHandle.Info processInfo = processHandle.info();
+        assertNotNull(processHandle.getPid());
+        assertEquals(false, processInfo.arguments()
+          .isPresent());
+        assertEquals(true, processInfo.command()
+          .isPresent());
+        assertTrue(processInfo.command()
+          .get()
+          .contains("java"));
+        assertEquals(true, processInfo.startInstant()
+          .isPresent());
+        assertEquals(true, processInfo.totalCpuDuration()
+          .isPresent());
+        assertEquals(true, processInfo.user()
+          .isPresent());
+    }
+
+    @Test
+    public void givenLiveProcesses_whenInvokeGetInfo_thenSuccess() {
+        Stream<ProcessHandle> liveProcesses = ProcessHandle.allProcesses();
+        liveProcesses.filter(ProcessHandle::isAlive)
+            .forEach(ph -> {
+                assertNotNull(ph.getPid());
+                assertEquals(true, ph.info()
+                  .command()
+                  .isPresent());
+                assertEquals(true, ph.info()
+                  .startInstant()
+                  .isPresent());
+                assertEquals(true, ph.info()
+                  .totalCpuDuration()
+                  .isPresent());
+                assertEquals(true, ph.info()
+                  .user()
+                  .isPresent());
+            });
+    }
+
+    @Test
+    public void givenProcess_whenGetChildProcess_thenSuccess() throws IOException {
+        int childProcessCount = 5;
+        for (int i = 0; i < childProcessCount; i++) {
+            String javaCmd = ProcessUtils.getJavaCmd()
+              .getAbsolutePath();
+            ProcessBuilder processBuilder
+              = new ProcessBuilder(javaCmd, "-version");
+            processBuilder.inheritIO().start();
+        }
+
+        Stream<ProcessHandle> children = ProcessHandle.current()
+          .children();
+        children.filter(ProcessHandle::isAlive)
+          .forEach(ph -> log.info("PID: {}, Cmd: {}", ph.getPid(), ph.info()
+            .command()));
+        Stream<ProcessHandle> descendants = ProcessHandle.current()
+          .descendants();
+        descendants.filter(ProcessHandle::isAlive)
+          .forEach(ph -> log.info("PID: {}, Cmd: {}", ph.getPid(), ph.info()
+            .command()));
+    }
+
+    @Test
+    public void givenProcess_whenAddExitCallback_thenSuccess() throws Exception {
+        String javaCmd = ProcessUtils.getJavaCmd()
+          .getAbsolutePath();
+        ProcessBuilder processBuilder
+          = new ProcessBuilder(javaCmd, "-version");
+        Process process = processBuilder.inheritIO()
+          .start();
+        ProcessHandle processHandle = process.toHandle();
+
+        log.info("PID: {} has started", processHandle.getPid());
+        CompletableFuture<ProcessHandle> onProcessExit = processHandle.onExit();
+        onProcessExit.get();
+        assertEquals(false, processHandle.isAlive());
+        onProcessExit.thenAccept(ph -> {
+            log.info("PID: {} has stopped", ph.getPid());
+        });
+    }
+
+}