java API方法可以返回不同的类型，如何定义返回类型？

Question

I have the following API method:

  @GetMapping
  public ResponseEntity<List<Project>> getProjects(@RequestParam(required = false) String userName, @RequestParam(required = false) boolean additionalInfo) {
    return ResponseEntity.ok(projectService.getProjects(userName, additionalInfo));
  }

它当前返回ResponseEntity<List<Project>>。但是如果可选参数additionalInfo为真，我想返回ResponseEntity<List<ProjectAdditionalInfoDTO>>。如何定义返回类型，以指示它们都可以返回？当然我可以用^{，但那会很难看

Answer 1

我会让事情简单化，只是把事情分成两个独立的控制器方法。。。e、 g

@GetMapping
public ResponseEntity<List<Project>> getProjects(@RequestParam(required=false) String userName) {
    //...
}

@GetMapping
public ResponseEntity<List<ProjectAdditionalInfoDTO>> getProjectsWithAdditionalInfos(@RequestParam(required=false) String userName, @RequestParam(required=true) boolean additionalInfo) {
    //...
}