From c45d69388f697546a9cbfe38b4cee2f695c1bfa7 Mon Sep 17 00:00:00 2001
From: Pazis <pazis.x@gmail.com>
Date: Tue, 11 Feb 2020 23:40:59 +0330
Subject: [PATCH] java.net.SocketException: Connection reset (#8707)

* initial commit

* fix
---
 .../socketexception/SocketClient.java         | 32 +++++++++++++
 .../socketexception/SocketServer.java         | 45 +++++++++++++++++++
 .../SocketExceptionHandlingUnitTest.java      | 31 +++++++++++++
 3 files changed, 108 insertions(+)
 create mode 100644 core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/socketexception/SocketClient.java
 create mode 100644 core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/socketexception/SocketServer.java
 create mode 100644 core-java-modules/core-java-exceptions-2/src/test/java/com/baeldung/socketexception/SocketExceptionHandlingUnitTest.java

diff --git a/core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/socketexception/SocketClient.java b/core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/socketexception/SocketClient.java
new file mode 100644
index 0000000000..5c3596e890
--- /dev/null
+++ b/core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/socketexception/SocketClient.java
@@ -0,0 +1,32 @@
+package com.baeldung.socketexception;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.Socket;
+
+public class SocketClient {
+
+    private Socket clientSocket;
+    private PrintWriter out;
+    private BufferedReader in;
+
+    public void startConnection(String ip, int port) throws IOException {
+        clientSocket = new Socket(ip, port);
+        out = new PrintWriter(clientSocket.getOutputStream(), true);
+        in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+    }
+
+    public String sendMessage(String msg) throws IOException {
+        out.println(msg);
+        return in.readLine();
+    }
+
+    public void stopConnection() throws IOException {
+        in.close();
+        out.close();
+        clientSocket.close();
+    }
+
+}
diff --git a/core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/socketexception/SocketServer.java b/core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/socketexception/SocketServer.java
new file mode 100644
index 0000000000..ad6fab738f
--- /dev/null
+++ b/core-java-modules/core-java-exceptions-2/src/main/java/com/baeldung/socketexception/SocketServer.java
@@ -0,0 +1,45 @@
+package com.baeldung.socketexception;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class SocketServer {
+
+    private ServerSocket serverSocket;
+    private Socket clientSocket;
+    private PrintWriter out;
+    private BufferedReader in;
+
+    public void start(int port) {
+        try {
+            serverSocket = new ServerSocket(port);
+            clientSocket = serverSocket.accept();
+            out = new PrintWriter(clientSocket.getOutputStream(), true);
+            in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+            String msg = in.readLine();
+            if (msg.contains("hi"))
+                out.println("hi");
+            else
+                out.println("didn't understand");
+            close();
+            stop();
+        } catch (IOException e) {
+            
+        }
+    }
+
+    private void close() throws IOException {
+        in.close();
+        out.close();
+    }
+
+    private void stop() throws IOException {
+        clientSocket.close();
+        serverSocket.close();
+    }
+
+}
diff --git a/core-java-modules/core-java-exceptions-2/src/test/java/com/baeldung/socketexception/SocketExceptionHandlingUnitTest.java b/core-java-modules/core-java-exceptions-2/src/test/java/com/baeldung/socketexception/SocketExceptionHandlingUnitTest.java
new file mode 100644
index 0000000000..08b21c6299
--- /dev/null
+++ b/core-java-modules/core-java-exceptions-2/src/test/java/com/baeldung/socketexception/SocketExceptionHandlingUnitTest.java
@@ -0,0 +1,31 @@
+package com.baeldung.socketexception;
+
+import java.io.IOException;
+import java.net.SocketException;
+import java.util.concurrent.Executors;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class SocketExceptionHandlingUnitTest {
+
+    @BeforeClass
+    public static void runServer() throws IOException, InterruptedException {
+        Executors.newSingleThreadExecutor()
+            .submit(() -> new SocketServer().start(6699));
+        Thread.sleep(100);
+    }
+
+    @Test
+    public void givenRunningServer_whenConnectToClosedSocket_thenHandleException() throws IOException {
+        SocketClient client = new SocketClient();
+        client.startConnection("127.0.0.1", 6699);
+        try {
+            client.sendMessage("hi");
+            client.sendMessage("hi again");
+        } catch (SocketException e) {
+            client.stopConnection();
+        }
+    }
+
+}