Scripting: body access decoded and array jsonpath in exchange expressions (#2236)

predic8 · web-flow · commit 99f5e9573caa · 2025-10-31T11:54:47.000+01:00
* fix: decodierung of body content for if, call, setHeader. Make jsonpath accept arrays as input.

* fix: decodierung of body content for if, call, setHeader. Make jsonpath accept arrays as input.

* fix: CallInterceptor Keep transfer- and content-encoding

* refactor: CallInterceptor copy just bytes and let setBodyContent handle transfer encoding

* refactor: minor

* refactor: minor

* refactor: minor

* refactor: minor
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/apikey/extractors/ApiKeyExpressionExtractor.java b/core/src/main/java/com/predic8/membrane/core/interceptor/apikey/extractors/ApiKeyExpressionExtractor.java
@@ -25,6 +25,7 @@
 
 import static com.predic8.membrane.core.interceptor.Interceptor.Flow.REQUEST;
 import static com.predic8.membrane.core.lang.ExchangeExpression.Language.SPEL;
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
 import static com.predic8.membrane.core.security.ApiKeySecurityScheme.In.EXPRESSION;
 
 /**
@@ -53,7 +54,7 @@ public class ApiKeyExpressionExtractor implements ApiKeyExtractor, Polyglot {
 
     @Override
     public void init(Router router) {
-        exchangeExpression = ExchangeExpression.newInstance(router, language, expression);
+        exchangeExpression = expression(router, language, expression);
     }
 
     @Override
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/balancer/PolyglotSessionIdExtractor.java b/core/src/main/java/com/predic8/membrane/core/interceptor/balancer/PolyglotSessionIdExtractor.java
@@ -24,6 +24,8 @@
 import com.predic8.membrane.core.lang.ExchangeExpression;
 import com.predic8.membrane.core.lang.ExchangeExpression.Language;
 
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
+
 @MCElement(name = "sessionIdExtractor")
 public class PolyglotSessionIdExtractor extends AbstractXmlElement implements SessionIdExtractor, Polyglot {
 
@@ -33,7 +35,7 @@ public class PolyglotSessionIdExtractor extends AbstractXmlElement implements Se
 
     public void init(Router router) {
         if (sessionSource != null && !sessionSource.isEmpty()) {
-            exchangeExpression = ExchangeExpression.newInstance(router, language, sessionSource);
+            exchangeExpression = expression(router, language, sessionSource);
         }
     }
 
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/flow/CallInterceptor.java b/core/src/main/java/com/predic8/membrane/core/interceptor/flow/CallInterceptor.java
@@ -53,7 +53,7 @@ public class CallInterceptor extends AbstractExchangeExpressionInterceptor {
      * and are not added to the current message.
      */
     private static final List<String> REMOVE_HEADERS = List.of(
-            SERVER, TRANSFER_ENCODING, CONTENT_ENCODING
+            SERVER, CONTENT_ENCODING, TRANSFER_ENCODING
     );
 
     private String method = GET;
@@ -87,7 +87,11 @@ private Outcome handleInternal(Exchange exc) {
         }
 
         try {
-            exc.getRequest().setBodyContent(newExc.getResponse().getBody().getContent());
+            /**
+             * The content is copied from the response with decoding. The response headers transfer-encoding
+             * and content-encoding are removed by the setBodyContent method.
+             */
+            exc.getRequest().setBodyContent(newExc.getResponse().getBodyAsStreamDecoded().readAllBytes());
             copyHeadersFromResponseToRequest(newExc, exc);
             return CONTINUE;
         } catch (Exception e) {
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/flow/ForInterceptor.java b/core/src/main/java/com/predic8/membrane/core/interceptor/flow/ForInterceptor.java
@@ -29,6 +29,7 @@
 import static com.predic8.membrane.core.interceptor.Outcome.ABORT;
 import static com.predic8.membrane.core.interceptor.Outcome.CONTINUE;
 import static com.predic8.membrane.core.lang.ExchangeExpression.Language.SPEL;
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
 
 /**
  * @description Iterates over a collection extracted from the <code>Exchange</code> and applies
@@ -56,7 +57,7 @@ public class ForInterceptor extends AbstractFlowWithChildrenInterceptor {
     public void init() {
         super.init();
         try {
-            exchangeExpression = ExchangeExpression.newInstance(router, language, in);
+            exchangeExpression = expression(router, language, in);
         } catch (ConfigurationException ce) {
             throw new ConfigurationException(ce.getMessage() + """
                     
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/flow/IfInterceptor.java b/core/src/main/java/com/predic8/membrane/core/interceptor/flow/IfInterceptor.java
@@ -26,6 +26,7 @@
 import static com.predic8.membrane.core.interceptor.Outcome.ABORT;
 import static com.predic8.membrane.core.interceptor.Outcome.*;
 import static com.predic8.membrane.core.lang.ExchangeExpression.Language.*;
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
 
 /**
  * @description <p>
@@ -52,7 +53,7 @@ public IfInterceptor() {
     @Override
     public void init() {
         super.init();
-        exchangeExpression = ExchangeExpression.newInstance(router, language, test);
+        exchangeExpression = expression(router, language, test);
     }
 
     @Override
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/flow/choice/Case.java b/core/src/main/java/com/predic8/membrane/core/interceptor/flow/choice/Case.java
@@ -25,6 +25,7 @@
 import org.slf4j.LoggerFactory;
 
 import static com.predic8.membrane.core.lang.ExchangeExpression.Language.SPEL;
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
 
 @MCElement(name = "case", topLevel = false)
 public class Case extends InterceptorContainer {
@@ -36,7 +37,7 @@ public class Case extends InterceptorContainer {
     private ExchangeExpression exchangeExpression;
 
     public void init(Router router) {
-        exchangeExpression = ExchangeExpression.newInstance(router, language, test);
+        exchangeExpression = expression(router, language, test);
     }
 
     boolean evaluate(Exchange exc, Flow flow) {
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/idempotency/IdempotencyInterceptor.java b/core/src/main/java/com/predic8/membrane/core/interceptor/idempotency/IdempotencyInterceptor.java
@@ -32,6 +32,7 @@
 import static com.predic8.membrane.core.interceptor.Outcome.ABORT;
 import static com.predic8.membrane.core.interceptor.Outcome.CONTINUE;
 import static com.predic8.membrane.core.lang.ExchangeExpression.Language.SPEL;
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
 
 /**
  * @description <p>Prevents duplicate request processing based on a dynamic idempotency key.</p>
@@ -54,7 +55,7 @@ public class IdempotencyInterceptor extends AbstractInterceptor {
     @Override
     public void init() {
         super.init();
-        exchangeExpression = ExchangeExpression.newInstance(router, language, key);
+        exchangeExpression = expression(router, language, key);
         processedKeys = CacheBuilder.newBuilder()
                 .maximumSize(10000)
                 .expireAfterWrite(expiration, TimeUnit.SECONDS)
diff --git a/core/src/main/java/com/predic8/membrane/core/interceptor/ratelimit/RateLimitInterceptor.java b/core/src/main/java/com/predic8/membrane/core/interceptor/ratelimit/RateLimitInterceptor.java
@@ -30,6 +30,7 @@
 import static com.predic8.membrane.core.interceptor.Interceptor.Flow.REQUEST;
 import static com.predic8.membrane.core.interceptor.Interceptor.Flow.Set.*;
 import static com.predic8.membrane.core.interceptor.Outcome.*;
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
 import static com.predic8.membrane.core.util.HttpUtil.*;
 import static java.lang.String.*;
 
@@ -93,7 +94,7 @@ protected ExchangeExpression getExchangeExpression() {
         // If there is no expression use the client IP
         if (expression.isEmpty())
             return null;
-        return ExchangeExpression.newInstance(router, language, expression);
+        return expression(router, language, expression);
     }
 
     @Override
diff --git a/core/src/main/java/com/predic8/membrane/core/lang/ExchangeExpression.java b/core/src/main/java/com/predic8/membrane/core/lang/ExchangeExpression.java
@@ -48,7 +48,7 @@ enum Language {GROOVY, SPEL, XPATH, JSONPATH}
      */
     <T> T evaluate(Exchange exchange, Interceptor.Flow flow, Class<T> type) throws ExchangeExpressionException;
 
-    static ExchangeExpression newInstance(Router router, Language language, String expression) {
+    static ExchangeExpression expression(Router router, Language language, String expression) {
         return switch (language) {
             case GROOVY -> new GroovyExchangeExpression(router, expression);
             case SPEL -> new SpELExchangeExpression(expression,null);
diff --git a/core/src/main/java/com/predic8/membrane/core/lang/LazyBody.java b/core/src/main/java/com/predic8/membrane/core/lang/LazyBody.java
@@ -11,22 +11,33 @@
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License. */
-package com.predic8.membrane.core.lang.spel.spelable;
+package com.predic8.membrane.core.lang;
 
 import com.predic8.membrane.core.http.*;
 
-public class SpELBody {
+/**
+ * Enables the use of ${body} in scripting environments without reading the body from InputStream when it is not needed.
+ */
+public class LazyBody {
 
     /**
      * Store message instead of body to be able to extract even zipped bodies
      */
     final Message message;
 
-    public SpELBody(Message msg) {
+    public LazyBody(Message msg) {
         message = msg;
     }
 
     public Message getMessage() {
         return message;
     }
+
+    /**
+     * This method is called in an expression like "Body ${body}".
+     */
+    @Override
+    public String toString() {
+        return message.getBodyAsStringDecoded();
+    }
 }
diff --git a/core/src/main/java/com/predic8/membrane/core/lang/ScriptingUtils.java b/core/src/main/java/com/predic8/membrane/core/lang/ScriptingUtils.java
@@ -71,28 +71,26 @@ public static HashMap<String, Object> createParameterBindings(Router router, Exc
 
         if (msg != null) {
             params.put("message", msg);
+            params.put("body", new LazyBody(msg));
             params.put("header", msg.getHeader());
             params.put("headers", msg.getHeader());
             if (includeJsonObject) {
                 try {
                     log.info("Parsing body as JSON for scripting plugins");
-                    params.put("json",om.readValue(readInputStream(msg.getBodyAsStream()),Map.class));
+                    params.put("json", om.readValue(readInputStream(msg.getBodyAsStreamDecoded()), Map.class));
                 } catch (Exception e) {
                     log.warn("Can't parse body as JSON", e);
                 }
             }
         }
 
-        /**
-         properties does not work in Groovy based Template Interceptor!
-
-         Reason: properties is a special built-in property in Groovy. Every Groovy object has a properties property
-         that returns a Map of all the object's properties.
-
-         But it can be accessed in Groovy Interceptor
-
-         Decision: Keep it but change examples to use property, even for spel, ..
-        */
+        /*
+          properties does not work in Groovy based Template Interceptor!
+          Reason: properties is a special built-in property in Groovy. Every Groovy object has a properties property
+          that returns a Map of all the object's properties.
+          But it can be accessed in Groovy Interceptor
+          Decision: Keep it but change examples to use property, even for spel, ..
+         */
         params.put("properties", exc.getProperties());
 
         // Also expose properties unter props and property
diff --git a/core/src/main/java/com/predic8/membrane/core/lang/TemplateExchangeExpression.java b/core/src/main/java/com/predic8/membrane/core/lang/TemplateExchangeExpression.java
@@ -24,6 +24,7 @@
 import java.util.regex.*;
 
 import static com.predic8.membrane.core.lang.ExchangeExpression.Language.*;
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
 
 public class TemplateExchangeExpression extends AbstractExchangeExpression {
 
@@ -95,7 +96,7 @@ protected static List<Token> parseTokens(Router router, Language language, Strin
             }
             String expr = m.group(3);
             if (expr != null) {
-                tokens.add(new Expression(ExchangeExpression.newInstance(router, language, expr)));
+                tokens.add(new Expression(expression(router, language, expr)));
             }
         }
         log.debug("Tokens: {}", tokens);
diff --git a/core/src/main/java/com/predic8/membrane/core/lang/jsonpath/JsonpathExchangeExpression.java b/core/src/main/java/com/predic8/membrane/core/lang/jsonpath/JsonpathExchangeExpression.java
@@ -140,6 +140,6 @@ private boolean convertToBoolean(Object o) {
     }
 
     private Object execute(Exchange exchange, Flow flow) throws IOException {
-        return JsonPath.read(om.readValue(exchange.getMessage(flow).getBodyAsStream(), Map.class), expression);
+        return JsonPath.read(om.readValue(exchange.getMessage(flow).getBodyAsStreamDecoded(), Object.class), expression);
     }
 }
diff --git a/core/src/main/java/com/predic8/membrane/core/lang/spel/SpELExchangeEvaluationContext.java b/core/src/main/java/com/predic8/membrane/core/lang/spel/SpELExchangeEvaluationContext.java
@@ -18,6 +18,7 @@
 import com.predic8.membrane.core.exchange.*;
 import com.predic8.membrane.core.http.*;
 import com.predic8.membrane.core.interceptor.Interceptor.*;
+import com.predic8.membrane.core.lang.*;
 import com.predic8.membrane.core.lang.spel.functions.*;
 import com.predic8.membrane.core.lang.spel.spelable.*;
 import com.predic8.membrane.core.lang.spel.typeconverters.*;
@@ -39,7 +40,7 @@ public class SpELExchangeEvaluationContext extends StandardEvaluationContext {
 
     private final Exchange exchange;
     private final Message message;
-    private final SpELBody body; // Is used by SpEL in scripts
+    private final LazyBody body; // Is used by SpEL in scripts
 
     // Avoid the common plural error
     private final SpELLablePropertyAware headers;
@@ -70,7 +71,7 @@ public SpELExchangeEvaluationContext(Exchange exchange, Flow flow) {
         this.exchange = exchange;
         this.flow = flow;
         this.message = exchange.getMessage(flow);
-        this.body = new SpELBody(message);
+        this.body = new LazyBody(message);
 
         pathParam = new SpELPathParameters(exchange);
         properties = new SpELProperties(exchange.getProperties());
@@ -174,7 +175,7 @@ public Message getMessage() {
         return message;
     }
 
-    public SpELBody getBody() { return body; }
+    public LazyBody getBody() { return body; }
 
     public String getPath() {
         return path;
diff --git a/core/src/main/java/com/predic8/membrane/core/lang/spel/typeconverters/SpELBodyToStringTypeConverter.java b/core/src/main/java/com/predic8/membrane/core/lang/spel/typeconverters/SpELBodyToStringTypeConverter.java
@@ -13,17 +13,17 @@
    limitations under the License. */
 package com.predic8.membrane.core.lang.spel.typeconverters;
 
-import com.predic8.membrane.core.lang.spel.spelable.*;
+import com.predic8.membrane.core.lang.*;
 import com.predic8.membrane.core.util.*;
 import org.slf4j.*;
 import org.springframework.core.convert.converter.*;
 
-public class SpELBodyToStringTypeConverter implements Converter<SpELBody, String> {
+public class SpELBodyToStringTypeConverter implements Converter<LazyBody, String> {
 
     private static final Logger log = LoggerFactory.getLogger(SpELBodyToStringTypeConverter.class.getName());
 
     @Override
-    public String convert(SpELBody body) {
+    public String convert(LazyBody body) {
         try {
             return new String(MessageUtil.getContent(body.getMessage()));
         } catch (Exception e) {
diff --git a/core/src/main/java/com/predic8/membrane/core/openapi/serviceproxy/APIProxy.java b/core/src/main/java/com/predic8/membrane/core/openapi/serviceproxy/APIProxy.java
@@ -35,6 +35,7 @@
 import java.util.*;
 
 import static com.predic8.membrane.core.lang.ExchangeExpression.Language.SPEL;
+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;
 
 /**
  * @description The api proxy extends the serviceProxy with API related functions like OpenAPI support and path parameters.
@@ -82,7 +83,7 @@ public void setSpecs(List<OpenAPISpec> specs) {
     public void init() {
         super.init();
         if (test != null && !test.isEmpty()) {
-            exchangeExpression = ExchangeExpression.newInstance(router, language, test);
+            exchangeExpression = expression(router, language, test);
         }
         key = new APIProxyKey(key, exchangeExpression, !specs.isEmpty());
         initOpenAPI();
diff --git a/core/src/main/java/com/predic8/membrane/core/util/MessageUtil.java b/core/src/main/java/com/predic8/membrane/core/util/MessageUtil.java
@@ -36,36 +36,36 @@ public class MessageUtil {
 		saxParserFactory.setValidating(false);
 	}
 
-	public static InputStream getContentAsStream(Message res) throws IOException {
-		if (res.isGzip()) {
-			return new GZIPInputStream(res.getBodyAsStream());
+	public static InputStream getContentAsStream(Message msg) throws IOException {
+		if (msg.isGzip()) {
+			return new GZIPInputStream(msg.getBodyAsStream());
 		}
-		if (res.isDeflate()) {
-			return new ByteArrayInputStream(getDecompressedData(res.getBody().getContent()));
+		if (msg.isDeflate()) {
+			return new ByteArrayInputStream(getDecompressedData(msg.getBody().getContent()));
 		}
-		if (res.isBrotli()) {
-			return new BrotliInputStream(res.getBodyAsStream());
+		if (msg.isBrotli()) {
+			return new BrotliInputStream(msg.getBodyAsStream());
 		}
-		return res.getBodyAsStream();
+		return msg.getBodyAsStream();
 	}
 	
-	public static byte[] getContent(Message res) throws Exception {
-		if (res.isGzip()) {
-			try (InputStream lInputStream = res.getBodyAsStream();
+	public static byte[] getContent(Message msg) throws Exception {
+		if (msg.isGzip()) {
+			try (InputStream lInputStream = msg.getBodyAsStream();
 				 GZIPInputStream lGZIPInputStream = new GZIPInputStream(lInputStream)) {
                 return lGZIPInputStream.readAllBytes();
             }
 		}
-		if (res.isDeflate()) {
-			return getDecompressedData(res.getBody().getContent());
+		if (msg.isDeflate()) {
+			return getDecompressedData(msg.getBody().getContent());
 		}
-		if (res.isBrotli()) {
-			try (InputStream lInputStream = res.getBodyAsStream();
+		if (msg.isBrotli()) {
+			try (InputStream lInputStream = msg.getBodyAsStream();
 				 BrotliInputStream lBrotliInputStream = new BrotliInputStream(lInputStream)) {
 				return lBrotliInputStream.readAllBytes();
 			}
 		}
-		return res.getBody().getContent();
+		return msg.getBody().getContent();
 	}
 	
 	public static Source getSOAPBody(InputStream stream) {
diff --git a/core/src/test/java/com/predic8/membrane/core/interceptor/flow/CallInterceptorTest.java b/core/src/test/java/com/predic8/membrane/core/interceptor/flow/CallInterceptorTest.java
diff --git a/core/src/test/java/com/predic8/membrane/core/interceptor/flow/ChooseInterceptorTest.java b/core/src/test/java/com/predic8/membrane/core/interceptor/flow/ChooseInterceptorTest.java
diff --git a/core/src/test/java/com/predic8/membrane/core/interceptor/flow/invocation/FlowTestInterceptors.java b/core/src/test/java/com/predic8/membrane/core/interceptor/flow/invocation/FlowTestInterceptors.java
diff --git a/core/src/test/java/com/predic8/membrane/core/interceptor/lang/SetPropertyInterceptorSpELTest.java b/core/src/test/java/com/predic8/membrane/core/interceptor/lang/SetPropertyInterceptorSpELTest.java
diff --git a/core/src/test/java/com/predic8/membrane/core/lang/AbstractExchangeExpressionTest.java b/core/src/test/java/com/predic8/membrane/core/lang/AbstractExchangeExpressionTest.java
diff --git a/core/src/test/java/com/predic8/membrane/core/lang/jsonpath/JsonpathExchangeExpressionTest.java b/core/src/test/java/com/predic8/membrane/core/lang/jsonpath/JsonpathExchangeExpressionTest.java
diff --git a/core/src/test/java/com/predic8/membrane/core/openapi/serviceproxy/APIProxyKeyComplexMatchTest.java b/core/src/test/java/com/predic8/membrane/core/openapi/serviceproxy/APIProxyKeyComplexMatchTest.java

Original file line number	Diff line number	Diff line change
`@@ -24,6 +24,8 @@`
`24`	`24`	`import com.predic8.membrane.core.lang.ExchangeExpression;`
`25`	`25`	`import com.predic8.membrane.core.lang.ExchangeExpression.Language;`
`26`	`26`
	`27`	`+import static com.predic8.membrane.core.lang.ExchangeExpression.expression;`
	`28`	`+`
`27`	`29`	`@MCElement(name = "sessionIdExtractor")`
`28`	`30`	`public class PolyglotSessionIdExtractor extends AbstractXmlElement implements SessionIdExtractor, Polyglot {`
`29`	`31`
`@@ -33,7 +35,7 @@ public class PolyglotSessionIdExtractor extends AbstractXmlElement implements Se`
`33`	`35`
`34`	`36`	`public void init(Router router) {`
`35`	`37`	`if (sessionSource != null && !sessionSource.isEmpty()) {`
`36`		`- exchangeExpression = ExchangeExpression.newInstance(router, language, sessionSource);`
	`38`	`+ exchangeExpression = expression(router, language, sessionSource);`
`37`	`39`	`}`
`38`	`40`	`}`
`39`	`41`