Spring ReST controller: how to avoid methods with same RequestParams

Question

In a Spring ReST Controller class, there are three methods with identical @RequestParams, but different RequestMappings and behavior, like in the following (simplified) example:

@RequestMapping(method = GET, value = "/search")
    public MySearchResponse findAll(
            @RequestParam(required = false, value = "foo") String foo,
            @RequestParam(required = false, value = "bar") String bar,
            @RequestParam(required = false, value = "baz") Long baz,
            @RequestParam(required = false, value = "fooBar") Long fooBar
    ) { ...}

@RequestMapping(method = GET, value = "/export")
    public MyExportResponse exportAll(
            @RequestParam(required = false, value = "foo") String foo,
            @RequestParam(required = false, value = "bar") String bar,
            @RequestParam(required = false, value = "baz") Long baz,
            @RequestParam(required = false, value = "fooBar") Long fooBar
    ) { ...}

Is there a way to avoid code duplication concerning the @RequestParam's?

1

Use an object to bind to. – M. Deinum Nov 07 '16 at 13:54

score 1 · Accepted Answer · edited May 23 '17 at 12:07

1

Replace them with a single object.

static class MyParmeters {
    String foo;
    String bar;
    Long baz;
    Long fooBar;
}

@RequestMapping(method = GET, value = "/search")
public MySearchResponse findAll(MyParmeters params) { ... }

@RequestMapping(method = GET, value = "/export")
public MyExportResponse exportAll(MyParameters params) { ... }

See also How to bind @RequestParam to object in Spring MVC.

edited May 23 '17 at 12:07

Community

1
1

answered Nov 07 '16 at 13:54

OrangeDog

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That seems to be quite a nice solution :-) Is there a way to conveniently check if the `required`-Constraint is fulfilled (in case there are `@RequestParams` with attribute `required=true`) – Mr.Radar Nov 07 '16 at 14:06
1

[Spring MVC: How to perform validation?](http://stackoverflow.com/q/12146298/476716) – OrangeDog Nov 07 '16 at 14:07

score 0 · Answer 2 · answered Nov 07 '16 at 13:57

You can define parent type called MyResponse and then you can use ResponseEntity as shown below:

@RequestMapping(method = GET, value = "/searchOrExport")
public ResponseEntity<MyResponse> exportAll(@RequestParam(required = false, value = "foo") String foo,
            @RequestParam(required = false, value = "bar") String bar,
            @RequestParam(required = false, value = "baz") Long baz,
            @RequestParam(required = false, value = "fooBar") Long fooBar) {
      //code to handle search and Export
}

Bean class API shown below:

public abstract class MyResponse  {
    //any common properties add here
}


public class MySearchResponse implements MyResponse {
   //add MySearchResponse properties
}

public class MyExportResponse implements MyResponse {
   //add MyExportResponse properties
}

Spring ReST controller: how to avoid methods with same RequestParams

2 Answers2