Support compilation of map indexing with primitive in SpEL

sbrannen · sbrannen · commit aed1d5f76271 · 2024-05-28T10:39:54.000+02:00
Prior to this commit, the Spring Expression Language (SpEL) failed to compile an expression that indexed into a Map using a primitive literal (boolean, int, long, float, or double). This commit adds support for compilation of such expressions by ensuring that primitive literals are boxed into their corresponding wrapper types in the compiled bytecode. Closes gh-32903 (cherry picked from commit e9de426)
diff --git a/spring-expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java b/spring-expression/src/main/java/org/springframework/expression/spel/ast/Indexer.java
@@ -283,9 +283,7 @@ else if (this.indexedType == IndexedType.MAP) {
 				mv.visitLdcInsn(mapKeyName);
 			}
 			else {
-				cf.enterCompilationScope();
-				index.generateCode(mv, cf);
-				cf.exitCompilationScope();
+				generateIndexCode(mv, cf, index, Object.class);
 			}
 			mv.visitMethodInsn(
 					INVOKEINTERFACE, "java/util/Map", "get", "(Ljava/lang/Object;)Ljava/lang/Object;", true);
diff --git a/spring-expression/src/test/java/org/springframework/expression/spel/SpelCompilationCoverageTests.java b/spring-expression/src/test/java/org/springframework/expression/spel/SpelCompilationCoverageTests.java
@@ -554,6 +554,53 @@ void indexIntoListUsingIntegerWrapper() {
 			assertThat(getAst().getExitDescriptor()).isEqualTo("Ljava/lang/Object");
 		}
 
+		@Test  // gh-32903
+		void indexIntoMapUsingPrimitiveLiteral() {
+			Map<Object, String> map = Map.of(
+					false, "0",   // BooleanLiteral
+					1, "ABC",     // IntLiteral
+					2L, "XYZ",    // LongLiteral
+					9.99F, "~10", // FloatLiteral
+					3.14159, "PI" // RealLiteral
+				);
+			context.setVariable("map", map);
+
+			// BooleanLiteral
+			expression = parser.parseExpression("#map[false]");
+			assertThat(expression.getValue(context)).isEqualTo("0");
+			assertCanCompile(expression);
+			assertThat(expression.getValue(context)).isEqualTo("0");
+			assertThat(getAst().getExitDescriptor()).isEqualTo("Ljava/lang/Object");
+
+			// IntLiteral
+			expression = parser.parseExpression("#map[1]");
+			assertThat(expression.getValue(context)).isEqualTo("ABC");
+			assertCanCompile(expression);
+			assertThat(expression.getValue(context)).isEqualTo("ABC");
+			assertThat(getAst().getExitDescriptor()).isEqualTo("Ljava/lang/Object");
+
+			// LongLiteral
+			expression = parser.parseExpression("#map[2L]");
+			assertThat(expression.getValue(context)).isEqualTo("XYZ");
+			assertCanCompile(expression);
+			assertThat(expression.getValue(context)).isEqualTo("XYZ");
+			assertThat(getAst().getExitDescriptor()).isEqualTo("Ljava/lang/Object");
+
+			// FloatLiteral
+			expression = parser.parseExpression("#map[9.99F]");
+			assertThat(expression.getValue(context)).isEqualTo("~10");
+			assertCanCompile(expression);
+			assertThat(expression.getValue(context)).isEqualTo("~10");
+			assertThat(getAst().getExitDescriptor()).isEqualTo("Ljava/lang/Object");
+
+			// RealLiteral
+			expression = parser.parseExpression("#map[3.14159]");
+			assertThat(expression.getValue(context)).isEqualTo("PI");
+			assertCanCompile(expression);
+			assertThat(expression.getValue(context)).isEqualTo("PI");
+			assertThat(getAst().getExitDescriptor()).isEqualTo("Ljava/lang/Object");
+		}
+
 		private String stringify(Object object) {
 			Stream<? extends Object> stream;
 			if (object instanceof Collection<?> collection) {

Original file line number	Diff line number	Diff line change
`@@ -283,9 +283,7 @@ else if (this.indexedType == IndexedType.MAP) {`
`283`	`283`	`mv.visitLdcInsn(mapKeyName);`
`284`	`284`	`}`
`285`	`285`	`else {`
`286`		`- cf.enterCompilationScope();`
`287`		`- index.generateCode(mv, cf);`
`288`		`- cf.exitCompilationScope();`
	`286`	`+ generateIndexCode(mv, cf, index, Object.class);`
`289`	`287`	`}`
`290`	`288`	`mv.visitMethodInsn(`
`291`	`289`	`INVOKEINTERFACE, "java/util/Map", "get", "(Ljava/lang/Object;)Ljava/lang/Object;", true);`