Maintain compatibility with Java 11

Author: Stypox

pom.xml

@@ -18,6 +18,8 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.source>11</maven.compiler.source>
     </properties>
     <dependencies>
         <dependency>
@@ -172,9 +174,8 @@
                 <artifactId>maven-compiler-plugin</artifactId>
                 <version>3.14.0</version>
                 <configuration>
-                    <debug>true</debug>
-                    <debuglevel>none</debuglevel>
-                    <release>17</release>
+                    <debug>false</debug>
+                    <release>11</release>
                     <compilerArgument>-Xlint:all</compilerArgument>
                     <compilerArguments>
                         <Werror />

src/main/java/com/grack/nanojson/LazyString.java

@@ -101,7 +101,8 @@ public boolean equals(Object obj) {
             return true;
         if (!(obj instanceof CharSequence))
             return false;
-        if (obj instanceof LazyString other) {
+        if (obj instanceof LazyString) {
+            LazyString other = (LazyString) obj;
             String str = stringValue; // Local ref copy to avoid race
             String otherStr = other.stringValue; // Local ref copy to avoid race
             if (str != null && otherStr != null) {