fix #853 - repair classloader for spring (#870)

* fix #853 - repair classloader for spring

* Fix code format

* fix #853 - repair classloader for spring - test

* fix #853 - repair classloader for spring - fix code format

---------

Co-authored-by: Marvin <[email protected]>
Co-authored-by: Marvin Froeder <[email protected]>
Co-authored-by: kkrzywanski <[email protected]>

Author: 3 people

querydsl-tooling/querydsl-codegen-utils/src/main/java/com/querydsl/codegen/utils/JDKEvaluatorFactory.java

@@ -22,6 +22,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import javax.tools.JavaCompiler;
 import javax.tools.SimpleJavaFileObject;
 import javax.tools.StandardLocation;
@@ -50,7 +51,10 @@ public JDKEvaluatorFactory(ClassLoader parent, JavaCompiler compiler) {
     this.fileManager =
         new MemFileManager(parent, compiler.getStandardFileManager(null, null, null));
     this.compiler = compiler;
-    this.classpath = SimpleCompiler.getClassPath(parent);
+    this.classpath =
+        Optional.of(SimpleCompiler.getClassPath(parent))
+            .filter(s -> !s.isEmpty())
+            .orElseGet(() -> SimpleCompiler.getClassPath(compiler.getClass().getClassLoader()));
     this.loader = fileManager.getClassLoader(StandardLocation.CLASS_OUTPUT);
     this.compilationOptions = Arrays.asList("-classpath", classpath, "-g:none");
   }

querydsl-tooling/querydsl-codegen-utils/src/test/java/com/querydsl/codegen/utils/JDKEvaluatorFactoryTest.java

@@ -7,6 +7,7 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
+import com.querydsl.codegen.utils.support.ClassLoaderWrapper;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
@@ -153,4 +154,27 @@ private Object evaluate(
             constants);
     return evaluator.evaluate(args.toArray());
   }
+
+  @Test
+  public void CustomClassLoader() {
+    var source = "a.getName()";
+    var projectionType = String.class;
+    var names = Collections.singletonList("a");
+    var types = Collections.<Class<?>>singletonList(TestEntity.class);
+    var args = Arrays.asList(new TestEntity("Hello World"));
+
+    var classLoader = new ClassLoaderWrapper(getClass().getClassLoader());
+    var factory = new JDKEvaluatorFactory(classLoader);
+
+    assertThat(
+            factory
+                .createEvaluator(
+                    "return " + source + ";",
+                    projectionType,
+                    names.toArray(String[]::new),
+                    types.toArray(Class[]::new),
+                    Collections.<String, Object>emptyMap())
+                .evaluate(args.toArray()))
+        .isEqualTo("Hello World");
+  }
 }

querydsl-tooling/querydsl-codegen-utils/src/test/java/com/querydsl/codegen/utils/support/ClassLoaderWrapper.java

@@ -0,0 +1,18 @@
+package com.querydsl.codegen.utils.support;
+
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.Collections;
+import java.util.Enumeration;
+
+public class ClassLoaderWrapper extends URLClassLoader {
+  public ClassLoaderWrapper(ClassLoader parent) {
+    super(new URL[0], parent);
+  }
+
+  @Override
+  public Enumeration<URL> findResources(String name) throws IOException {
+    return Collections.emptyEnumeration();
+  }
+}