Refactor FieldReader boxed types to eliminate duplication

[Copilot]

Eight FieldReader classes (Int32, Int64, Int8, Int16, Float, Double, Bool, BigDecimal) contained identical error handling and schema validation logic. This refactors them to share a common base class.

Changes

• New base class: FieldReaderBoxedType<T, V> consolidates try-catch-NullOnError pattern and schema validation
• Refactored classes: 8 readers now extend base class, implementing only readValue() for type-specific reading
• Special cases preserved:
  • FieldReaderDouble: Maintains defaultValue early-return behavior
  • FieldReaderInt64: Preserves TypeUtils.toLong conversion for validation while setting original value
  • FieldReaderBool: Validates converted Boolean value, not original input

Before/After

// Before: FieldReaderInt32 (57 lines)
@Override
public void readFieldValue(JSONReader jsonReader, T object) {
    Integer value;
    try {
        value = jsonReader.readInt32();
    } catch (Exception e) {
        if ((jsonReader.features(this.features) & JSONReader.Feature.NullOnError.mask) != 0) {
            value = null;
        } else {
            throw e;
        }
    }
    propertyAccessor.setObject(object, value);
}

// After: FieldReaderInt32 (35 lines)
@Override
protected Integer readValue(JSONReader jsonReader) {
    return jsonReader.readInt32();
}

Impact

• Net reduction: 55 lines (119 added base class, 174 removed from subclasses)
• Eliminates ~180 lines of duplicated error handling
• Centralizes future bug fixes and improvements
• All 7,804 core tests passing

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• a.b.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java -javaagent:/home/REDACTED/.m2/repository/org/jacoco/org.jacoco.agent/0.8.13/org.jacoco.agent-0.8.13-runtime.jar=destfile=/home/REDACTED/work/fastjson2/fastjson2/core/target/jacoco.exec,excludes=com/alibaba/fastjson2/benchmark:com/alibaba/example/springtest:co (dns block)
• central.sonatype.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.12/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.12/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.12 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.12/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/fastjson2/fastjson2 org.codehaus.plexus.classworlds.launcher.Launcher clean compile -pl core -am -DskipTests (dns block)
• maven.aliyun.com
  • Triggering command: /usr/lib/jvm/temurin-17-jdk-amd64/bin/java /usr/lib/jvm/temurin-17-jdk-amd64/bin/java --enable-native-access=ALL-UNNAMED -classpath /usr/share/apache-maven-3.9.12/boot/plexus-classworlds-2.9.0.jar -Dclassworlds.conf=/usr/share/apache-maven-3.9.12/bin/m2.conf -Dmaven.home=/usr/share/apache-maven-3.9.12 -Dlibrary.jansi.path=/usr/share/apache-maven-3.9.12/lib/jansi-native -Dmaven.multiModuleProjectDirectory=/home/REDACTED/work/fastjson2/fastjson2 org.codehaus.plexus.classworlds.launcher.Launcher clean compile -pl core -am -DskipTests (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

---

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[safe1ine]

@MonkeyCode-AI review 一下

[MonkeyCode-AI]

MonkeyCode-AI 正在分析任务...

[MonkeyCode-AI]

我是 MonkeyCode AI 编程助手，你可以在 GitHub 仓库的 PR 中 at @MonkeyCode-AI 来呼唤我。

任务执行细节请参考: https://monkeycode-ai.com/tasks/public?id=588fc27e-c930-4e24-939f-f3ea9e4bf626

代码审查结果

通过引入 FieldReaderBoxedType 统一了 boxed 基础类型的 NullOnError 与 schema 校验逻辑，整体重构方向正确，但新增基类的泛型/类型安全与部分子类的 readFieldValue(JSONReader) 语义存在潜在行为变化，建议在合入前做小幅修正。

✨ 代码亮点

• 将 NullOnError try-catch 模式与 schema 校验集中到抽象基类，明显降低重复代码与后续维护成本
• 对 Double 的 defaultValue 早返回与 Int64/Bool 的特殊校验语义做了保留处理，避免常见的重构回归

🚨 Critical	⚠️ Warning	💡 Suggestion
0	2	0

[MonkeyCode-AI]

Warning

⚠️ readFieldValue(JSONReader) 返回值语义可能变化：Int8/Int16 现在返回 Byte/Short 而非原先的 Integer

在重构前，FieldReaderInt8/FieldReaderInt16 覆盖了 public Object readFieldValue(JSONReader jsonReader) 并直接 return jsonReader.readInt32()，即“读取但不落字段”时返回的是 Integer。重构后它们继承 FieldReaderBoxedType.readFieldValue(JSONReader) 并返回 readValue(jsonReader)，而 readValue 内部将 int32 转换成 Byte/Short，因此该方法返回类型从 Integer 变成了 Byte/Short。

这属于可观察的行为变化：如果框架/上层逻辑在某些路径依赖该 Object 返回值的具体运行时类型（例如统一当作 Integer 处理、或做 instanceof Integer 分支），可能会产生兼容性问题。虽然 PR 描述没有提到这一点，但从 diff 可以确定语义确实发生了变化。

建议: 为 Int8/Int16 恢复原先 readFieldValue(JSONReader) 的返回值语义（返回 Integer），同时保留 readFieldValue(JSONReader,T) 写入字段时的 Byte/Short 转换。也可以在基类中拆分“赋值类型”和“readFieldValue(JsonReader)返回类型”，但最小改动是在子类里单独 override readFieldValue(JSONReader)。

Suggested change

	protected Byte readValue(JSONReader jsonReader) {
	Integer intValue = jsonReader.readInt32();
	return intValue == null ? null : intValue.byteValue();
	}
	@Override
	public Object readFieldValue(JSONReader jsonReader) {
	return jsonReader.readInt32();
	}
	@Override
	protected Byte readValue(JSONReader jsonReader) {
	Integer intValue = jsonReader.readInt32();
	return intValue == null ? null : intValue.byteValue();
	}

[MonkeyCode-AI]

Warning

⚠️ readFieldValue(JSONReader) 返回值语义可能变化：Int16 现在返回 Short 而非原先的 Integer

同 Int8：重构前 FieldReaderInt16.readFieldValue(JSONReader) 返回 jsonReader.readInt32()（Integer），重构后继承基类返回 readValue(jsonReader)（Short）。这可能影响依赖返回类型为 Integer 的调用路径。

建议: 在 FieldReaderInt16 中覆盖 readFieldValue(JSONReader) 返回 Integer，保持兼容；readFieldValue(JSONReader,T) 仍通过 readValue 写入 Short。

Suggested change

	protected Short readValue(JSONReader jsonReader) {
	Integer intValue = jsonReader.readInt32();
	return intValue == null ? null : intValue.shortValue();
	}
	@Override
	public Object readFieldValue(JSONReader jsonReader) {
	return jsonReader.readInt32();
	}
	@Override
	protected Short readValue(JSONReader jsonReader) {
	Integer intValue = jsonReader.readInt32();
	return intValue == null ? null : intValue.shortValue();
	}