Multiple requestmapping value with path variables

Question

@RequestMapping(value = {"/abcd", "/employees/{value}/{id}"})
public String getEmployees(
      @PathVariable(value = "value") String val, 
      @PathVariable(value = "id") String id,
      @RequestParam(value = "param", required = false) String value) {
        // ********

}

For one url I am passing the path variable and for one I am not. But I want both the url to hit the same API. How can I achieve it?

Answer 1

You can now have optional path variables via support for Java 8 Optional. At least Spring version 4.x will be required.

@RequestMapping({"/abcd", "/employees/{value}/{id}"})
public String getEmployees(
    @PathVariable("value") Optional<String> val, 
    @PathVariable("id") Optional<String> id,
    @RequestParam("param") Optional<String> value
) {
    // ********
}

N.B. this doesn't work with the optional primitives (OptionalInt, etc.).

Answer 2

Just found a way to do this without using multiple methods.

First create a simple class to hold the path variables:

public class EmployeesRequest {
  private String value;
  private String id;

  public String getValue() {
    return this.value;
  }

  public void setValue(String value) {
    this.value = value;
  }

  public String getId() {
    return this.id;
  }

  public void setId(String id) {
    this.id = id;
  }
}

Then define your controller method like this:

@RequestMapping(value={
  "/abcd",
  "/employees/{value}/{id}"
})
public String getEmployees(@RequestParam(value="param", required=false) String param,
                           EmployeesRequest request) {
  if (request.getValue() != null) {
    // do something
  } else {
    // do something else
  }
}

Spring will automatically map any path variables available to the EmployeesRequest class. Spring will also do this for any request parameters so you can simplify things further by adding the request parameter to EmployeesRequest:

public class EmployeesRequest {
  private String value;
  private String id;
  private String param;

  public String getValue() {
    return this.value;
  }

  public void setValue(String value) {
    this.value = value;
  }

  public String getId() {
    return this.id;
  }

  public void setId(String id) {
    this.id = id;
  }

  public String getParam() {
    return this.param;
  }

  public void setParam(String param) {
    this.param = param;
  }
}

And then finally:

@RequestMapping(value={
  "/abcd",
  "/employees/{value}/{id}"
})
public String getEmployees(EmployeesRequest request) {
  if (request.getValue() != null) {
    // do something
  } else {
    // do something else
  }
}

An added benefit of this solution is that now you can support both variables or request parameters. Meaning all of these would be valid:

• /abcd
• /abcd?param=123
• /abcd?value=123&id=456&param=789
• /employees/123/456
• /employees/123/456?param=123

Answer 3

We can't have optional path variables, you can have two controller methods which can call the same service.

First Method

@RequestMapping("/abcd")
public String getEmployees(@RequestParam(value="param", required=false)String value){}

Second Method

@RequestMapping("/employees/{value}/{id}")
public String getEmployees(@PathVariable(value="value") String val, @PathVariable(value="id") String id, @RequestParam(value="param", required=false) String value){}

For @RequestParam we can use,

@RequestParam(value="somevalue",required=false)

for optional params rather than a pathVariable