Adding URI segment specific encoding

README.md

@@ -113,6 +113,14 @@ See [Advanced Usage](#advanced-usage) for more examples.
 >
 > `@RequestLine` and `@QueryMap` templates do not encode slash `/` characters by default.  To change this behavior, set the `decodeSlash` property on the `@RequestLine` to `false`.  
 
+> **What about plus? `+`**
+>
+> Per the URI specification, a `+` sign is allowed in both the path and query segments of a URI, however, handling of
+> the symbol on the query can be inconsistent.  In some legacy systems, the `+` is equivalent to the a space.  Feign takes the approach of modern systems, where a
+> `+` symbol should not represent a space and is explicitly encoded as `%2B` when found on a query string.
+>
+> If you wish to use `+` as a space, then use the literal ` ` character or encode the value directly as `%20`
+
 ##### Custom Expansion
 
 The `@Param` annotation has an optional property `expander` allowing for complete control over the individual parameter's expansion.

core/src/main/java/feign/template/Expressions.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2018 The Feign Authors
+ * Copyright 2012-2019 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -11,10 +11,10 @@
  * or implied. See the License for the specific language governing permissions and limitations under
  * the License.
  */
-
 package feign.template;
 
 import feign.Util;
+import feign.template.UriUtils.FragmentType;
 import java.util.ArrayList;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -29,11 +29,10 @@ public final class Expressions {
 
   static {
     expressions = new LinkedHashMap<>();
-    expressions.put(Pattern.compile("\\+(\\w[-\\w.]*[ ]*)(:(.+))?"), ReservedExpression.class);
     expressions.put(Pattern.compile("(\\w[-\\w.]*[ ]*)(:(.+))?"), SimpleExpression.class);
   }
 
-  public static Expression create(final String value) {
+  public static Expression create(final String value, final FragmentType type) {
 
     /* remove the start and end braces */
     final String expression = stripBraces(value);
@@ -54,7 +53,6 @@ public static Expression create(final String value) {
 
     Entry<Pattern, Class<? extends Expression>> matchedExpression = matchedExpressionEntry.get();
     Pattern expressionPattern = matchedExpression.getKey();
-    Class<? extends Expression> expressionType = matchedExpression.getValue();
 
     /* create a new regular expression matcher for the expression */
     String variableName = null;
@@ -69,7 +67,7 @@ public static Expression create(final String value) {
       }
     }
 
-    return new SimpleExpression(variableName, variablePattern);
+    return new SimpleExpression(variableName, variablePattern, type);
   }
 
   private static String stripBraces(String expression) {
@@ -82,36 +80,21 @@ private static String stripBraces(String expression) {
     return expression;
   }
 
-  /**
-   * Expression that does not encode reserved characters. This expression adheres to RFC 6570
-   * <a href="https://tools.ietf.org/html/rfc6570#section-3.2.3">Reserved Expansion (Level 2)</a>
-   * specification.
-   */
-  public static class ReservedExpression extends SimpleExpression {
-    private final String RESERVED_CHARACTERS = ":/?#[]@!$&\'()*+,;=";
-
-    ReservedExpression(String expression, String pattern) {
-      super(expression, pattern);
-    }
-
-    @Override
-    String encode(Object value) {
-      return UriUtils.encodeReserved(value.toString(), RESERVED_CHARACTERS, Util.UTF_8);
-    }
-  }
-
   /**
    * Expression that adheres to Simple String Expansion as outlined in <a
    * href="https://tools.ietf.org/html/rfc6570#section-3.2.2>Simple String Expansion (Level 1)</a>
    */
   static class SimpleExpression extends Expression {
 
-    SimpleExpression(String expression, String pattern) {
+    private final FragmentType type;
+
+    SimpleExpression(String expression, String pattern, FragmentType type) {
       super(expression, pattern);
+      this.type = type;
     }
 
     String encode(Object value) {
-      return UriUtils.encode(value.toString(), Util.UTF_8);
+      return UriUtils.encodeReserved(value.toString(), type, Util.UTF_8);
     }
 
     @Override

core/src/main/java/feign/template/Template.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2018 The Feign Authors
+ * Copyright 2012-2019 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -13,6 +13,7 @@
  */
 package feign.template;
 
+import feign.template.UriUtils.FragmentType;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.List;
@@ -80,9 +81,9 @@ public String expand(Map<String, ?> variables) {
         Object value = variables.get(expression.getName());
         if (value != null) {
           String expanded = expression.expand(value, this.encode.isEncodingRequired());
-          if (!this.encodeSlash) {
+          if (this.encodeSlash) {
             logger.fine("Explicit slash decoding specified, decoding all slashes in uri");
-            expanded = expanded.replaceAll("\\%2F", "/");
+            expanded = expanded.replaceAll("/", "%2F");
           }
           resolved.append(expanded);
         } else {
@@ -200,7 +201,9 @@ private void parseFragment(String fragment, boolean query) {
 
       if (chunk.startsWith("{")) {
         /* it's an expression, defer encoding until resolution */
-        Expression expression = Expressions.create(chunk);
+        FragmentType type = (query) ? FragmentType.QUERY : FragmentType.PATH_SEGMENT;
+
+        Expression expression = Expressions.create(chunk, type);
         if (expression == null) {
           this.templateChunks.add(Literal.create(encode(chunk, query)));
         } else {