BAEL-1991 - Understanding Process (#4863)

* Understanding Process * Refactored names * Refactored junit names based on document guidance * Added alive * renamed junits as behavior Driven requirements * Added alive method junit * added waitFor method time interval junit * getOutputStream * changed exception * dummy commit * Dummy Commit with blank lines * Fixed assert and commented @Test * fixed asserts * Replaced System.out.println with logging * replaced system.out.println with logging * Dummy commit to ensure clean build * Renamed Junit * Fixed extra spaces and typo * Uncommented @Test for 3 methods
2018-08-30 23:38:21 +05:30
parent 201d616c6b
commit aa2822c5fc
5 changed files with 269 additions and 0 deletions
@@ -0,0 +1,121 @@
+package com.baeldung.java9.process;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.lang.String;
+import java.util.Optional;
+import java.util.concurrent.TimeUnit;
+import java.lang.Integer;
+
+import org.junit.jupiter.api.Test;
+
+class ProcessUnderstandingTest {
+
+    @Test
+    public void givenSourceProgram_whenExecutedFromAnotherProgram_thenSourceProgramOutput3() throws IOException {
+        Process process = Runtime.getRuntime()
+            .exec("javac -cp src src\\main\\java\\com\\baeldung\\java9\\process\\OutputStreamExample.java");
+        process = Runtime.getRuntime()
+            .exec("java -cp  src/main/java com.baeldung.java9.process.OutputStreamExample");
+        BufferedReader output = new BufferedReader(new InputStreamReader(process.getInputStream()));
+        int value = Integer.parseInt(output.readLine());
+        assertEquals(3, value);            
+    }
+
+    @Test
+    public void givenSourceProgram_whenReadingInputStream_thenFirstLineEquals3() throws IOException {
+        Process process = Runtime.getRuntime()
+            .exec("javac -cp src src\\main\\java\\com\\baeldung\\java9\\process\\OutputStreamExample.java");
+        process = Runtime.getRuntime()
+            .exec("java -cp  src/main/java com.baeldung.java9.process.OutputStreamExample");
+        BufferedReader output = new BufferedReader(new InputStreamReader(process.getInputStream()));
+        int value = Integer.parseInt(output.readLine());
+        assertEquals(3, value);                   
+    }
+
+    @Test
+    public void givenSubProcess_whenEncounteringError_thenErrorStreamNotNull() throws IOException {
+        Process process = Runtime.getRuntime()
+            .exec("javac -cp src src\\main\\java\\com\\baeldung\\java9\\process\\ProcessCompilationError.java");
+        BufferedReader error = new BufferedReader(new InputStreamReader(process.getErrorStream()));
+        String errorString = error.readLine();
+        assertNotNull(errorString);
+    }
+
+    //@Test - windows specific
+    public void givenSubProcess_thenStartSuccessIsAlive() throws IOException {
+        ProcessBuilder builder = new ProcessBuilder("notepad.exe");
+        assertTrue(builder.start().isAlive());
+    }
+
+    //@Test - windows specific
+    public void givenSubProcess_whenDestroying_thenProcessNotAlive() throws IOException, InterruptedException {
+        ProcessBuilder builder = new ProcessBuilder("notepad.exe");
+        Process process = builder.start();
+        Thread.sleep(10000);
+        process.destroy();
+        assertFalse(process.isAlive());
+    }
+
+    //@Test - windows specific
+    public void givenSubProcess_whenAlive_thenDestroyForcibly() throws IOException, InterruptedException {
+        ProcessBuilder builder = new ProcessBuilder("notepad.exe");
+        Process process = builder.start();
+        Thread.sleep(10000);
+        process.destroy();
+        if (process.isAlive()) {
+            process.destroyForcibly();
+        }
+        assertFalse(process.isAlive());
+    }
+
+    //@Test - windows specific
+    public void givenSubProcess_checkAlive() throws IOException, InterruptedException {
+        ProcessBuilder builder = new ProcessBuilder("notepad.exe");
+        Process process = builder.start();
+        Thread.sleep(10000);
+        process.destroy();
+        assertFalse(process.isAlive());
+    }
+
+    @Test
+    public void givenProcessNotCreated_fromWithinJavaApplicationDestroying_thenProcessNotAlive() {
+        Optional<ProcessHandle> optionalProcessHandle = ProcessHandle.of(5232);
+        ProcessHandle processHandle = optionalProcessHandle.get();
+        processHandle.destroy();
+        assertFalse(processHandle.isAlive());
+    }
+
+    //@Test - windows specific
+    public void givenSubProcess_whenCurrentThreadWaitsIndefinitelyuntilSubProcessEnds_thenProcessWaitForReturnsGrt0() throws IOException, InterruptedException {
+        ProcessBuilder builder = new ProcessBuilder("notepad.exe");
+        Process process = builder.start();
+        assertThat(process.waitFor() >= 0);
+    }
+
+    //@Test - windows specific
+    public void givenSubProcess_whenCurrentThreadWaitsAndSubProcessNotTerminated_thenProcessWaitForReturnsFalse() throws IOException, InterruptedException {
+        ProcessBuilder builder = new ProcessBuilder("notepad.exe");
+        Process process = builder.start();
+        assertFalse(process.waitFor(1, TimeUnit.SECONDS));
+    }
+
+    //@Test - windows specific
+    public void givenSubProcess_whenCurrentThreadWillNotWaitIndefinitelyforSubProcessToEnd_thenProcessExitValueReturnsGrt0() throws IOException {
+        ProcessBuilder builder = new ProcessBuilder("notepad.exe");
+        Process process = builder.start();
+        assertThat(process.exitValue() >= 0);
+    }
+
+    @Test
+    public void givenRunningProcesses_whenFilterOnProcessIdRange_thenGetSelectedProcessPid() {
+        assertThat(((int) ProcessHandle.allProcesses()
+            .filter(ph -> (ph.pid() > 10000 && ph.pid() < 50000))
+            .count()) > 0);
+    }
+}