fix: exception when write replace return itself

src/main/java/com/caucho/hessian/io/JavaSerializer.java

@@ -146,14 +146,16 @@ public void writeObject(Object obj, AbstractHessianOutput out)
  try {
  if (_writeReplace != null) {
  Object repl = _writeReplace.invoke(obj, new Object[0]);
+ // for those writeReplaces that might return obj itself, no need to replace repl with obj
+ if (repl != obj) {
 
- out.removeRef(obj);
+  out.removeRef(obj);
 
- out.writeObject(repl);
+  out.writeObject(repl);
 
- out.replaceRef(repl, obj);
-
- return;
+  out.replaceRef(repl, obj);
+ return;
+ }
  }
  } catch (Exception e) {
  log.log(Level.FINE, e.toString(), e);

src/test/java/com/caucho/hessian/io/WriteReplaceTest.java

@@ -0,0 +1,129 @@
+/*
+ * Ant Group
+ * Copyright (c) 2004-2024 All Rights Reserved.
+ */
+package com.caucho.hessian.io;
+
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.Serializable;
+
+/**
+ *
+ * @author junyuan
+ * @version WriteReplaceTest.java, v 0.1 2024-03-20 10:34 junyuan Exp $
+ */
+public class WriteReplaceTest {
+ private static SerializerFactory factory;
+ private static ByteArrayOutputStream os;
+
+ @BeforeClass
+ public static void setUp() {
+ factory = new SerializerFactory();
+ os = new ByteArrayOutputStream();
+ }
+
+ @Test
+ public void TestWriteReplace() throws IOException {
+ TestObject origin = new TestObject();
+ origin.setName("testWR");
+
+ os.reset();
+ Hessian2Output output = new Hessian2Output(os);
+
+ output.setSerializerFactory(factory);
+ try {
+ output.writeObject(origin);
+ } catch (Exception e) {
+ Assert.fail("should be no exception");
+ }
+ output.flush();
+
+ ByteArrayInputStream is = new ByteArrayInputStream(os.toByteArray());
+ Hessian2Input input = new Hessian2Input(is);
+ input.setSerializerFactory(factory);
+ TestObject actual = (TestObject)input.readObject();
+ Assert.assertEquals(actual.name, origin.name);
+ }
+
+ @Test
+ public void TestWrappedWriteReplace() throws IOException {
+ WrappedTestObject origin = new WrappedTestObject();
+ TestObject testObject = new TestObject();
+ testObject.setName("testWR");
+ origin.setTestObject(testObject);
+
+ os.reset();
+ Hessian2Output output = new Hessian2Output(os);
+
+ output.setSerializerFactory(factory);
+ try {
+ output.writeObject(origin);
+ } catch (Exception e) {
+ Assert.fail("should be no exception");
+ }
+ output.flush();
+
+ ByteArrayInputStream is = new ByteArrayInputStream(os.toByteArray());
+ Hessian2Input input = new Hessian2Input(is);
+ input.setSerializerFactory(factory);
+ WrappedTestObject actual = (WrappedTestObject)input.readObject();
+ Assert.assertEquals(actual.testObject.name, origin.testObject.name);
+ }
+
+ private static class WrappedTestObject implements Serializable {
+ private TestObject testObject;
+
+ /**
+ * Getter method for property <tt>testObject</tt>.
+ *
+ * @return property value of testObject
+ */
+ public TestObject getTestObject() {
+ return testObject;
+ }
+
+ /**
+ * Setter method for property <tt>testObject</tt>.
+ *
+ * @param testObject value to be assigned to property testObject
+ */
+ public void setTestObject(TestObject testObject) {
+ this.testObject = testObject;
+ }
+ }
+
+
+ private static class TestObject implements Serializable {
+ private static final long serialVersionUID = -452701306050912437L;
+
+ String name;
+
+ Object writeReplace() {
+ return this;
+ }
+
+ /**
+ * Getter method for property <tt>name</tt>.
+ *
+ * @return property value of name
+ */
+ public String getName() {
+ return name;
+ }
+
+ /**
+ * Setter method for property <tt>name</tt>.
+ *
+ * @param name value to be assigned to property name
+ */
+ public void setName(String name) {
+ this.name = name;
+ }
+ }
+}