Update docs for message routers so that they compile

Author: mamachanko

src/reference/asciidoc/dsl.adoc

@@ -382,12 +382,12 @@ The fluent API also provides `AbstractMappingMessageRouter` options such as `cha
 [source,java]
 ----
 @Bean
-public IntegrationFlow routeFlow() {
+public IntegrationFlow routeFlowByLambda() {
     return IntegrationFlows.from("routerInput")
             .<Integer, Boolean>route(p -> p % 2 == 0,
                     m -> m.suffix("Channel")
-                            .channelMapping("true", "even")
-                            .channelMapping("false", "odd")
+                            .channelMapping(true, "even")
+                            .channelMapping(false, "odd")
             )
             .get();
 }
@@ -400,7 +400,7 @@ The following example shows a simple expression-based router:
 [source,java]
 ----
 @Bean
-public IntegrationFlow routeFlow() {
+public IntegrationFlow routeFlowByExpression() {
     return IntegrationFlows.from("routerInput")
             .route("headers['destChannel']")
             .get();
@@ -417,21 +417,21 @@ The `routeToRecipients()` method takes a `Consumer<RecipientListRouterSpec>`, as
 public IntegrationFlow recipientListFlow() {
     return IntegrationFlows.from("recipientListInput")
             .<String, String>transform(p -> p.replaceFirst("Payload", ""))
-                        .routeToRecipients(r -> r
-                .recipient("thing1-channel", "'thing1' == payload")
-                .recipient("thing2-channel", m ->
-                    m.getHeaders().containsKey("recipient")
-                        && (boolean) m.getHeaders().get("recipient"))
-                .recipientFlow("'thing1' == payload or 'thing2' == payload or 'thing3' == payload",
-                    f -> f.<String, String>transform(String::toUpperCase)
-                        .channel(c -> c.queue("recipientListSubFlow1Result")))
-                .recipientFlow((String p) -> p.startsWith("thing3"),
-                    f -> f.transform("Hello "::concat)
-                        .channel(c -> c.queue("recipientListSubFlow2Result")))
-                .recipientFlow(new FunctionExpression<Message<?>>(m ->
-                                             "thing3".equals(m.getPayload())),
-                    f -> f.channel(c -> c.queue("recipientListSubFlow3Result")))
-                .defaultOutputToParentFlow())
+            .routeToRecipients(r -> r
+                    .recipient("thing1-channel", "'thing1' == payload")
+                    .recipientMessageSelector("thing2-channel", m ->
+                            m.getHeaders().containsKey("recipient")
+                                    && (boolean) m.getHeaders().get("recipient"))
+                    .recipientFlow("'thing1' == payload or 'thing2' == payload or 'thing3' == payload",
+                            f -> f.<String, String>transform(String::toUpperCase)
+                                    .channel(c -> c.queue("recipientListSubFlow1Result")))
+                    .recipientFlow((String p) -> p.startsWith("thing3"),
+                            f -> f.transform("Hello "::concat)
+                                    .channel(c -> c.queue("recipientListSubFlow2Result")))
+                    .recipientFlow(new FunctionExpression<Message<?>>(m ->
+                                    "thing3".equals(m.getPayload())),
+                            f -> f.channel(c -> c.queue("recipientListSubFlow3Result")))
+                    .defaultOutputToParentFlow())
             .get();
 }
 ----