Spring4 MVC如何接收GET请求中的分号分隔参数

Great question! The semicolon-separated parameters in your URL are called Matrix Variables in Spring MVC, and here's how you can handle them in your Spring 4 REST controller:

Step 1: Enable Matrix Variables Support #

Spring 4 disables matrix variable handling by default (it automatically removes semicolon-containing content from URLs). You need to override this behavior first via configuration:

Option 1: Java-based Configuration

Create a configuration class extending WebMvcConfigurerAdapter (the standard way to customize Spring MVC in Spring 4) to enable matrix variables:

@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {
    @Override
    public void configurePathMatch(PathMatchConfigurer configurer) {
        UrlPathHelper urlPathHelper = new UrlPathHelper();
        // Disable removing semicolon content to allow matrix variables
        urlPathHelper.setRemoveSemicolonContent(false);
        configurer.setUrlPathHelper(urlPathHelper);
    }
}

Option 2: XML Configuration

If you're using XML-based Spring configuration, add this to your servlet context file:

<mvc:annotation-driven>
    <mvc:path-matching remove-semicolon-content="false"/>
</mvc:annotation-driven>

Step 2: Receive Matrix Variables in Your Controller #

Once configured, use the @MatrixVariable annotation to extract id1 and id2 from your URL. Here are two practical approaches:

Approach 1: Directly Extract Variables

For your example URL http://localhost:9080/myapp/v1/userdetails/{id1;id2}, the matrix variables are part of the userdetails path segment. You can extract them directly in your controller method parameters:

@RestController
@RequestMapping("/myapp/v1")
public class UserDetailsController {

    @GetMapping("/userdetails")
    public ResponseEntity<String> getUserDetails(
            @MatrixVariable("id1") String id1,
            @MatrixVariable("id2") String id2) {
        // Your business logic here (e.g., fetch user details using id1 and id2)
        return ResponseEntity.ok(String.format("Received id1: %s, id2: %s", id1, id2));
    }
}

Approach 2: Link to a Path Variable

If you prefer to define a placeholder in your path (like /userdetails/{userIds}), you can explicitly link the matrix variables to that path segment:

@RestController
@RequestMapping("/myapp/v1")
public class UserDetailsController {

    @GetMapping("/userdetails/{userIds}")
    public ResponseEntity<String> getUserDetails(
            @MatrixVariable(value = "id1", pathVar = "userIds") String id1,
            @MatrixVariable(value = "id2", pathVar = "userIds") String id2) {
        // Handle the parameters as needed
        return ResponseEntity.ok(String.format("id1: %s, id2: %s", id1, id2));
    }
}

This works for URLs like http://localhost:9080/myapp/v1/userdetails/id1=123;id2=456 or even http://localhost:9080/myapp/v1/userdetails/foo;id1=123;id2=456 (the path variable value doesn't affect matrix variable extraction).

Additional Tips #

• Make variables optional: Add required = false to @MatrixVariable if the parameter isn't mandatory (e.g., @MatrixVariable(value = "id1", required = false)).
• Collect all matrix variables: Use @MatrixVariable Map<String, String> matrixVars to get all matrix variables in a single map.
• Matrix variables can appear in any path segment: For example, http://localhost:9080/myapp/v1;version=1/userdetails;id1=123;id2=456 lets you extract version as another matrix variable.

内容的提问来源于stack exchange，提问作者MiniSu