Use fileToPath() (#3219)

* Use fileToPath()

This is a follow-up to PR 3210 on GitHub. See:
https://github.com/jenkinsci/jenkins/pull/3210#discussion_r160045107

* Switch two File.toPath() calls to Util.fileToPath()

* Delete an unused import

core/src/main/java/hudson/Util.java

@@ -193,13 +193,11 @@ public class Util {
 
         StringBuilder str = new StringBuilder((int)logfile.length());
 
-        try (BufferedReader r = Files.newBufferedReader(logfile.toPath(), charset)) {
+        try (BufferedReader r = Files.newBufferedReader(fileToPath(logfile), charset)) {
             char[] buf = new char[1024];
             int len;
             while ((len = r.read(buf, 0, buf.length)) > 0)
                 str.append(buf, 0, len);
-        } catch (InvalidPathException e) {
-            throw new IOException(e);
         }
 
         return str.toString();

core/src/main/java/hudson/model/Queue.java

@@ -64,7 +64,6 @@ import hudson.model.queue.WorkUnitContext;
 import hudson.security.ACL;
 import hudson.security.AccessControlled;
 import java.nio.file.Files;
-import java.nio.file.InvalidPathException;
 import jenkins.security.QueueItemAuthenticatorProvider;
 import jenkins.util.Timer;
 import hudson.triggers.SafeTimerTask;
@@ -377,15 +376,13 @@ public class Queue extends ResourceController implements Saveable {
             // first try the old format
             File queueFile = getQueueFile();
             if (queueFile.exists()) {
-                try (BufferedReader in = Files.newBufferedReader(queueFile.toPath(), Charset.defaultCharset())) {
+                try (BufferedReader in = Files.newBufferedReader(Util.fileToPath(queueFile), Charset.defaultCharset())) {
                     String line;
                     while ((line = in.readLine()) != null) {
                         AbstractProject j = Jenkins.getInstance().getItemByFullName(line, AbstractProject.class);
                         if (j != null)
                             j.scheduleBuild();
                     }
-                } catch (InvalidPathException e) {
-                    throw new IOException(e);
                 }
                 // discard the queue file now that we are done
                 queueFile.delete();

core/src/main/java/hudson/util/TextFile.java

@@ -25,6 +25,8 @@ package hudson.util;
 
 import com.google.common.collect.*;
 
+import hudson.Util;
+
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
 import javax.annotation.Nonnull;
@@ -69,12 +71,10 @@ public class TextFile {
     public String read() throws IOException {
         StringWriter out = new StringWriter();
         PrintWriter w = new PrintWriter(out);
-        try (BufferedReader in = Files.newBufferedReader(file.toPath(), StandardCharsets.UTF_8)) {
+        try (BufferedReader in = Files.newBufferedReader(Util.fileToPath(file), StandardCharsets.UTF_8)) {
             String line;
             while ((line = in.readLine()) != null)
                 w.println(line);
-        } catch (InvalidPathException e) {
-            throw new IOException(e);
         }
         return out.toString();
     }