#1142 better exception messages

src/main/java/org/takes/facets/auth/PsBasic.java

@@ -249,7 +249,10 @@ public Opt<Identity> enter(final String user, final String pwd) {
                         )
                     );
                 } catch (final UnsupportedEncodingException ex) {
-                    throw new IllegalStateException(ex);
+                    throw new IllegalStateException(
+                        String.format("Failed to decode URN '%s'", urn.get()),
+                        ex
+                    );
                 }
             } else {
                 identity = new Opt.Empty<>();
@@ -302,7 +305,10 @@ private Opt<String> urn(final String user, final String pwd) {
                     )
                 );
             } catch (final UnsupportedEncodingException ex) {
-                throw new IllegalStateException(ex);
+                throw new IllegalStateException(
+                    "Failed to encode user name or password",
+                    ex
+                );
             }
             final Opt<String> opt;
             if (urn == null) {

src/main/java/org/takes/facets/auth/codecs/CcCompact.java

@@ -54,7 +54,10 @@ public byte[] encode(final Identity identity) {
                 stream.writeUTF(ent.getValue());
             }
         } catch (final IOException ex) {
-            throw new IllegalArgumentException(ex);
+            throw new IllegalArgumentException(
+                "Failed to encode the identity",
+                ex
+            );
         }
         return data.toByteArray();
     }

src/main/java/org/takes/facets/auth/social/PsFacebook.java

@@ -188,11 +188,12 @@ private User fetch(final String token) {
                 this.requestor,
                 new DefaultJsonMapper(),
                 Version.LATEST
-            ).fetchObject(
-                "me", User.class
-            );
+            ).fetchObject("me", User.class);
         } catch (final FacebookException ex) {
-            throw new IllegalArgumentException(ex);
+            throw new IllegalArgumentException(
+                "Failed to fetch object from Facebook token",
+                ex
+            );
         }
     }
 

src/main/java/org/takes/facets/fork/FkHitRefresh.java

@@ -88,7 +88,10 @@ public FkHitRefresh(final File file, final List<String> cmd,
                 try {
                     new ProcessBuilder().command(cmd).start();
                 } catch (final IOException ex) {
-                    throw new IllegalStateException(ex);
+                    throw new IllegalStateException(
+                        String.format("Failed to run command '%s'", cmd),
+                        ex
+                    );
                 }
             },
             tke

src/main/java/org/takes/http/BkParallel.java

@@ -80,7 +80,10 @@ public BkParallel(final Back back, final ExecutorService svc) {
                     try {
                         back.accept(socket);
                     } catch (final IOException ex) {
-                        throw new IllegalStateException(ex);
+                        throw new IllegalStateException(
+                            "Socket wasn't accepted by the back",
+                            ex
+                        );
                     }
                 }
             )

src/main/java/org/takes/http/BkTimeable.java

@@ -75,7 +75,10 @@ public void run() {
                 TimeUnit.SECONDS.sleep(1L);
             } catch (final InterruptedException ex) {
                 Thread.currentThread().interrupt();
-                throw new IllegalStateException(ex);
+                throw new IllegalStateException(
+                    "Interrupted while waiting",
+                    ex
+                );
             }
         }
     }

src/main/java/org/takes/http/FtCli.java

@@ -115,7 +115,10 @@ public void start(final Exit exit) throws IOException {
                     try {
                         front.start(this.exit(exit));
                     } catch (final IOException ex) {
-                        throw new IllegalStateException(ex);
+                        throw new IllegalStateException(
+                            "Failed to start the front",
+                            ex
+                        );
                     }
                 }
             );

src/main/java/org/takes/http/FtRemote.java

@@ -123,20 +123,26 @@ public void exec(final FtRemote.Script script) throws Exception {
                         }
                     );
                 } catch (final IOException ex) {
-                    throw new IllegalStateException(ex);
+                    throw new IllegalStateException(
+                        "Failed to start the app thread",
+                        ex
+                    );
                 }
             }
         );
         thread.start();
         try {
             if (!latch.await(10L, TimeUnit.SECONDS)) {
                 throw new IllegalArgumentException(
-                    "failed to start the app"
+                    "Failed to start the app"
                 );
             }
         } catch (final InterruptedException ex) {
             Thread.currentThread().interrupt();
-            throw new IllegalStateException(ex);
+            throw new IllegalStateException(
+                "Interrupted while waiting for latch",
+                ex
+            );
         }
         final String protocol;
         if (this.secured) {
@@ -157,7 +163,10 @@ public void exec(final FtRemote.Script script) throws Exception {
             thread.join();
         } catch (final InterruptedException ex) {
             Thread.currentThread().interrupt();
-            throw new IllegalStateException(ex);
+            throw new IllegalStateException(
+                "Thread waiting interrupted",
+                ex
+            );
         }
     }
 

src/main/java/org/takes/http/Options.java

@@ -171,7 +171,7 @@ private static Map<String, String> asMap(final Iterable<String> args) {
             final Matcher matcher = ptn.matcher(arg);
             if (!matcher.matches()) {
                 throw new IllegalStateException(
-                    String.format("can't parse this argument: '%s'", arg)
+                    String.format("Can't parse this argument: '%s'", arg)
                 );
             }
             final String value = matcher.group(2);

src/main/java/org/takes/misc/Href.java

@@ -265,7 +265,10 @@ private static String encode(final String txt) {
                 txt, Charset.defaultCharset().name()
             );
         } catch (final UnsupportedEncodingException ex) {
-            throw new IllegalStateException(ex);
+            throw new IllegalStateException(
+                String.format("Failed to encode '%s'", txt),
+                ex
+            );
         }
     }
 
@@ -280,7 +283,10 @@ private static String decode(final String txt) {
                 txt, Charset.defaultCharset().name()
             );
         } catch (final UnsupportedEncodingException ex) {
-            throw new IllegalStateException(ex);
+            throw new IllegalStateException(
+                String.format("Failed to decode '%s'", txt),
+                ex
+            );
         }
     }
 

src/main/java/org/takes/rq/RqHeaders.java

@@ -103,7 +103,7 @@ public List<String> header(final CharSequence key)
                 list = new VerboseList<>(
                     Collections.emptyList(),
                     new FormattedText(
-                        "there are no headers by name \"%s\" among %d others: %s",
+                        "There are no headers by name \"%s\" among %d others: %s",
                         key,
                         this.map().size(),
                         this.map().keySet()
@@ -113,7 +113,7 @@ public List<String> header(final CharSequence key)
                 list = new VerboseList<>(
                     values,
                     new FormattedText(
-                        "there are only %d headers by name \"%s\"",
+                        "There are only %d headers by name \"%s\"",
                         values.size(),
                         key
                     )
@@ -139,18 +139,22 @@ private Map<String, List<String>> map() throws IOException {
             if (!head.hasNext()) {
                 throw new HttpException(
                     HttpURLConnection.HTTP_BAD_REQUEST,
-                    "a valid request must contain at least one line in the head"
+                    "A valid request must contain at least one line in the head"
                 );
             }
             head.next();
             final Map<String, List<String>> map = new HashMap<>(0);
+            int pos = 1;
             while (head.hasNext()) {
                 final String line = head.next();
                 final String[] parts = line.split(":", 2);
                 if (parts.length < 2) {
                     throw new HttpException(
                         HttpURLConnection.HTTP_BAD_REQUEST,
-                        String.format("invalid HTTP header: \"%s\"", line)
+                        String.format(
+                            "Invalid HTTP header on line #%d: \"%s\"",
+                            pos, line
+                        )
                     );
                 }
                 final String key = new UncheckedText(
@@ -164,6 +168,7 @@ private Map<String, List<String>> map() throws IOException {
                         new Trimmed(new TextOf(parts[1]))
                     ).asString()
                 );
+                pos += 1;
             }
             return map;
         }
@@ -232,7 +237,7 @@ public String single(final CharSequence name) throws IOException {
                 throw new HttpException(
                     HttpURLConnection.HTTP_BAD_REQUEST,
                     String.format(
-                        "header \"%s\" is mandatory, not found among %s",
+                        "Header \"%s\" is mandatory, not found among %s",
                         name, this.names()
                     )
                 );

src/main/java/org/takes/rq/form/RqFormBase.java

@@ -117,13 +117,17 @@ public Iterable<String> names() throws IOException {
      * @return Decoded
      */
     private static String decode(final Text txt) {
+        final String body = new UncheckedText(txt).asString();
         try {
             return URLDecoder.decode(
-                new UncheckedText(txt).asString(),
+                body,
                 Charset.defaultCharset().name()
             );
         } catch (final UnsupportedEncodingException ex) {
-            throw new IllegalStateException(ex);
+            throw new IllegalStateException(
+                String.format("Failed to decode '%s'", body),
+                ex
+            );
         }
     }
 

src/main/java/org/takes/rq/form/RqFormFake.java

@@ -117,7 +117,10 @@ private static String encode(final CharSequence txt) {
                 txt.toString(), Charset.defaultCharset().name()
             );
         } catch (final UnsupportedEncodingException ex) {
-            throw new IllegalStateException(ex);
+            throw new IllegalStateException(
+                String.format("Failed to encode '%s'", txt),
+                ex
+            );
         }
     }
 }

src/main/java/org/takes/rs/RsHeaders.java

@@ -103,7 +103,7 @@ public List<String> header(final CharSequence key)
                 list = new VerboseList<>(
                     Collections.emptyList(),
                     new FormattedText(
-                        "there are no headers by name \"%s\" among %d others: %s",
+                        "There are no headers by name \"%s\" among %d others: %s",
                         key,
                         this.map().size(),
                         this.map().keySet()
@@ -113,7 +113,7 @@ public List<String> header(final CharSequence key)
                 list = new VerboseList<>(
                     values,
                     new FormattedText(
-                        "there are only %d headers by name \"%s\"",
+                        "There are only %d headers by name \"%s\"",
                         values.size(),
                         key
                     )
@@ -139,18 +139,22 @@ private Map<String, List<String>> map() throws IOException {
             if (!head.hasNext()) {
                 throw new HttpException(
                     HttpURLConnection.HTTP_BAD_REQUEST,
-                    "a valid request must contain at least one line in the head"
+                    "A valid request must contain at least one line in the head"
                 );
             }
             head.next();
+            int pos = 1;
             final Map<String, List<String>> map = new HashMap<>(0);
             while (head.hasNext()) {
                 final String line = head.next();
                 final String[] parts = line.split(":", 2);
                 if (parts.length < 2) {
                     throw new HttpException(
                         HttpURLConnection.HTTP_BAD_REQUEST,
-                        String.format("invalid HTTP header: \"%s\"", line)
+                        String.format(
+                            "Invalid HTTP header on line #%d: \"%s\"",
+                            pos, line
+                        )
                     );
                 }
                 final String key = new UncheckedText(
@@ -164,6 +168,7 @@ private Map<String, List<String>> map() throws IOException {
                         new Trimmed(new TextOf(parts[1]))
                     ).asString()
                 );
+                pos += 1;
             }
             return map;
         }
@@ -232,7 +237,7 @@ public String single(final CharSequence name) throws IOException {
                 throw new HttpException(
                     HttpURLConnection.HTTP_BAD_REQUEST,
                     String.format(
-                        "header \"%s\" is mandatory, not found among %s",
+                        "Header \"%s\" is mandatory, not found among %s",
                         name, this.names()
                     )
                 );

src/main/java/org/takes/rs/RsPrint.java

@@ -133,15 +133,15 @@ public void printHead(final OutputStream output) throws IOException {
             if (pos == 0 && !RsPrint.FIRST.matcher(line).matches()) {
                 throw new IllegalArgumentException(
                     String.format(
-                        "first line of HTTP response \"%s\" doesn't match \"%s\" regular expression, but it should, according to RFC 7230",
+                        "First line of HTTP response \"%s\" doesn't match \"%s\" regular expression, but it should, according to RFC 7230",
                         line, RsPrint.FIRST
                     )
                 );
             }
             if (pos > 0 && !RsPrint.OTHERS.matcher(line).matches()) {
                 throw new IllegalArgumentException(
                     String.format(
-                        "header line #%d of HTTP response \"%s\" doesn't match \"%s\" regular expression, but it should, according to RFC 7230",
+                        "Header line #%d of HTTP response \"%s\" doesn't match \"%s\" regular expression, but it should, according to RFC 7230",
                         pos + 1, line, RsPrint.OTHERS
                     )
                 );

src/main/java/org/takes/rs/RsWithStatus.java

@@ -103,7 +103,7 @@ private static Iterable<String> head(final Response origin,
         if (status < 100 || status > 999) {
             throw new IllegalArgumentException(
                 String.format(
-                    "according to RFC 7230 HTTP status code must have three digits: %d",
+                    "According to RFC 7230 HTTP status code must have three digits: %d",
                     status
                 )
             );

src/main/java/org/takes/rs/RsXslt.java

@@ -137,7 +137,10 @@ private static InputStream transform(final TransformerFactory factory,
         try {
             input = RsXslt.consume(xml);
         } catch (final IOException ex) {
-            throw new IllegalStateException(ex);
+            throw new IllegalStateException(
+                "Failed to consume XML by XSLT",
+                ex
+            );
         }
         final ByteArrayOutputStream baos = new ByteArrayOutputStream();
         final Source xsl = RsXslt.stylesheet(
@@ -193,7 +196,7 @@ private static Source stylesheet(final TransformerFactory factory,
         );
         if (stylesheet == null) {
             throw new IllegalArgumentException(
-                "no associated stylesheet found in XML"
+                "No associated stylesheet found in XML"
             );
         }
         return stylesheet;
@@ -240,7 +243,10 @@ public Source resolve(final String href, final String base)
                 try {
                     input = uri.toURL().openStream();
                 } catch (final IOException ex) {
-                    throw new IllegalStateException(ex);
+                    throw new IllegalStateException(
+                        String.format("Failed to open URL '%s'", uri),
+                        ex
+                    );
                 }
             } else {
                 input = this.getClass().getResourceAsStream(uri.getPath());

src/main/java/org/takes/rs/xe/RsXembly.java

@@ -142,7 +142,10 @@ private static InputStream render(final Node dom,
                 )
             );
         } catch (final TransformerException ex) {
-            throw new IllegalStateException(ex);
+            throw new IllegalStateException(
+                "Failed to transform XML via XSLT",
+                ex
+            );
         }
         return new ByteArrayInputStream(baos.toByteArray());
     }