fix: Build by moving from findbugs to spotbugs and removing Java 7 tests

Actually the Travis build on master is broken because of an issue with findbugs 3.
Since findbugs is deprecated, its seems to be better to switch to spotbugs, the successor.
The pom.xml has been updated accordingly and some low hanging fruits have been fixed.

However the test show some concurrency issue, which might be considered to be fixed.

The test for Java 7 has been switched off in Travis as (a) the build is broken (see one of the latest Travis logs) and (b) spotbugs requires Java 8+

.travis.yml

@@ -1,6 +1,5 @@
 language: java
 jdk:
-  - openjdk7
   - openjdk8
   - openjdk9
 notifications:

pom.xml

@@ -109,12 +109,20 @@
         </executions>
       </plugin>
 
-      <!-- run findbugs check -->
+      <!-- run spotbugs check -->
       <plugin>
-        <groupId>org.codehaus.mojo</groupId>
-        <artifactId>findbugs-maven-plugin</artifactId>
-        <version>3.0.3</version>
-        <executions>
+        <groupId>com.github.spotbugs</groupId>
+        <artifactId>spotbugs-maven-plugin</artifactId>
+        <version>3.1.12.2</version>
+        <dependencies>
+          <!-- overwrite dependency on spotbugs if you want to specify the version of spotbugs -->
+          <dependency>
+            <groupId>com.github.spotbugs</groupId>
+            <artifactId>spotbugs</artifactId>
+            <version>4.0.0-beta4</version>
+          </dependency>
+        </dependencies>
+         <executions>
           <execution>
             <phase>process-test-classes</phase>
             <goals>
@@ -124,9 +132,9 @@
         </executions>
         <configuration>
           <effort>Max</effort>
-          <includeTests>true</includeTests>
-          <threshold>Low</threshold>
-          <xmlOutput>true</xmlOutput>
+          <includeTests>false</includeTests>
+          <relaxed>true</relaxed>
+          <spotbugsXmlOutput>true</spotbugsXmlOutput>
           <failOnError>false</failOnError>
         </configuration>
       </plugin>

src/main/java/jnr/unixsocket/UnixDatagramChannel.java

@@ -87,9 +87,12 @@ private UnixDatagramChannel() throws IOException {
     UnixDatagramChannel(int fd, State initialState, boolean initialBoundState) {
         super(fd);
         stateLock.writeLock().lock();
-        state = initialState;
-        bindHandler = new BindHandler(initialBoundState);
-        stateLock.writeLock().unlock();
+        try {
+            state = initialState;
+            bindHandler = new BindHandler(initialBoundState);
+        } finally {
+            stateLock.writeLock().unlock();
+        }
     }
 
     UnixDatagramChannel(int fd, UnixSocketAddress remote) throws IOException {

src/main/java/jnr/unixsocket/UnixSocket.java

@@ -117,12 +117,7 @@ public InputStream getInputStream() throws IOException {
 
     @Override
     public SocketAddress getLocalSocketAddress() {
-        UnixSocketAddress address = chan.getLocalSocketAddress();
-        if (address != null) {
-            return address;
-        } else {
-            return null;
-        }
+        return chan.getLocalSocketAddress();
     }
 
     @Override

src/main/java/jnr/unixsocket/UnixSocketChannel.java

@@ -80,7 +80,7 @@ public static final UnixSocketChannel create() throws IOException {
     public static final UnixSocketChannel[] pair() throws IOException {
         int[] sockets = { -1, -1 };
         Native.socketpair(ProtocolFamily.PF_UNIX, Sock.SOCK_STREAM, 0, sockets);
-        return new UnixSocketChannel[] { 
+        return new UnixSocketChannel[] {
                 new UnixSocketChannel(sockets[0], State.CONNECTED, true),
                 new UnixSocketChannel(sockets[1], State.CONNECTED, true) };
     }
@@ -100,17 +100,20 @@ public static final UnixSocketChannel fromFD(int fd) {
     UnixSocketChannel() throws IOException {
         this(Native.socket(ProtocolFamily.PF_UNIX, Sock.SOCK_STREAM, 0));
     }
-    
+
     UnixSocketChannel(int fd) {
         this(fd, State.CONNECTED, false);
     }
 
     UnixSocketChannel(int fd, State initialState, boolean initialBoundState) {
         super(fd);
         stateLock.writeLock().lock();
-        state = initialState;
-        bindHandler = new BindHandler(initialBoundState);
-        stateLock.writeLock().unlock();
+        try {
+            state = initialState;
+            bindHandler = new BindHandler(initialBoundState);
+        } finally {
+            stateLock.writeLock().unlock();
+        }
     }
 
     private boolean doConnect(SockAddrUnix remote) throws IOException {
@@ -146,7 +149,7 @@ public boolean connect(UnixSocketAddress remote) throws IOException {
             return true;
         }
     }
-    
+
     boolean isBound() {
         return bindHandler.isBound();
     }

src/test/java/jnr/unixsocket/example/UnixServer.java

@@ -106,7 +106,7 @@ public final boolean rxready() {
                 ByteBuffer buf = ByteBuffer.allocate(1024);
                 int n = channel.read(buf);
                 UnixSocketAddress remote = channel.getRemoteSocketAddress();
-                System.out.printf("Read in %d bytes from %s\n", n, remote);
+                System.out.printf("Read in %d bytes from %s%n", n, remote);
 
                 if (n > 0) {
                     buf.flip();