baomidou/mybatis-plus · error · BuilderException

The properties element cannot specify both a URL and a resou

Error message

The properties element cannot specify both a URL and a resource based property file reference.  Please specify one or the other.

What it means

Thrown by propertiesElement when the <properties> element in mybatis-config.xml declares both a resource attribute and a url attribute. MyBatis can load external properties from exactly one source per element — a classpath resource or a URL — and refuses the ambiguous combination rather than guessing precedence.

Source

Thrown at mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/MybatisXMLConfigBuilder.java:246

    }

    private void reflectorFactoryElement(XNode context) throws Exception {
        if (context != null) {
            String type = context.getStringAttribute("type");
            ReflectorFactory factory = (ReflectorFactory) resolveClass(type).getDeclaredConstructor().newInstance();
            configuration.setReflectorFactory(factory);
        }
    }

    private void propertiesElement(XNode context) throws Exception {
        if (context == null) {
            return;
        }
        Properties defaults = context.getChildrenAsProperties();
        String resource = context.getStringAttribute("resource");
        String url = context.getStringAttribute("url");
        if (resource != null && url != null) {
            throw new BuilderException(
                "The properties element cannot specify both a URL and a resource based property file reference.  Please specify one or the other.");
        }
        if (resource != null) {
            defaults.putAll(Resources.getResourceAsProperties(resource));
        } else if (url != null) {
            defaults.putAll(Resources.getUrlAsProperties(url));
        }
        Properties vars = configuration.getVariables();
        if (vars != null) {
            defaults.putAll(vars);
        }
        parser.setVariables(defaults);
        configuration.setVariables(defaults);
    }

    private void settingsElement(Properties props) {
        configuration.setAutoMappingBehavior(AutoMappingBehavior.valueOf(props.getProperty("autoMappingBehavior", "PARTIAL")));
        configuration.setAutoMappingUnknownColumnBehavior(AutoMappingUnknownColumnBehavior.valueOf(props.getProperty("autoMappingUnknownColumnBehavior", "NONE")));

View on GitHub (pinned to bf67d90747)

Solutions

1. Keep only the attribute matching where the file lives: resource for classpath files, url for absolute/file/remote URLs.
2. If both sources are genuinely needed, load one into the other (e.g. import inside the properties file) or merge them into a single file.
3. In Spring Boot, prefer externalizing via application.yml/property sources instead of the MyBatis <properties> element.

Example fix

<!-- before -->
<properties resource="db.properties" url="file:///etc/app/db.properties"/>

<!-- after -->
<properties resource="db.properties"/>

// lint the <properties> element before build
try (InputStream in = Resources.getResourceAsStream("mybatis-config.xml")) {
    javax.xml.parsers.Document doc = javax.xml.parsers.DocumentBuilderFactory.newInstance()
        .newDocumentBuilder().parse(in);
    org.w3c.dom.NodeList nl = doc.getElementsByTagName("properties");
    for (int i = 0; i < nl.getLength(); i++) {
        org.w3c.dom.Element el = (org.w3c.dom.Element) nl.item(i);
        if (el.hasAttribute("resource") && el.hasAttribute("url"))
            throw new IllegalStateException("<properties> has both resource and url");
    }
}

Catch BuilderException about 'both a URL and a resource'; delete one attribute per the message and rebuild.

When it happens

Trigger: <properties resource="db.properties" url="file:///etc/app/db.properties"> in mybatis-config.xml, with both attributes present.

Common situations: Migrating from file-based to classpath-based property files and leaving the old attribute; merging config snippets from different environments where one used resource and the other url.

Related errors

• Error parsing SQL Mapper Configuration. Cause: %s
• A mapper element may only specify a url, resource or class,
• Environment requires an id attribute.
• %s already contains value for %s
• %s does not contain value for %s

AI-assisted analysis of baomidou/mybatis-plus@bf67d90747 (2026-08-14). Data as JSON: /api/errors/9e897f8a211b9942. Report an issue: GitHub.