Question

I am very new for spring mvc and java. i want to return a json data instead of string

@RequestMapping(value = "/ex/foos", method = RequestMethod.GET, produces = "application/json")
@ResponseBody
public String getFoosAsJsonFromREST() {
    return "{\"name\":\"MyNode\", \"width\":200, \"height\":100}";
}

actual output:
"{\"name\":\"MyNode\", \"width\":200, \"height\":100}"

output i want:
{"name":"MyNode", "width":200, "height":100}

i followed the link but i still can't get literal json output

@RequestMapping(value = "/ex/foos", method = RequestMethod.GET, produces = "application/json") @ResponseBody public JsonNode getFoosAsJsonFromREST() {

  String everything = "{\"a\":2,\"b\":\"astring\",\"c\":6}";
  ObjectMapper mapper = new ObjectMapper();
  JsonNode node = mapper.readTree(everything);
  return node;
}

output { "result": false, "message": "Unexpected end-of-String when base64 content\n at [Source: N/A; line: -1, column: -1]" }

Answer 1

你快到了：）

JSON只是一种对象格式，因此您必须返回一个具有键：值对的对象。

@RequestMapping(value = "/ex/foos", method = RequestMethod.GET, produces = "application/json")
@ResponseBody
public MyJSONRespone getFoosAsJsonFromREST() {
  MyJSONRespone myResponse = new MyJSONRespone();
  myResponse.setName("MyNode");
  myResponse.setWidth(200);
  myResponse.setHeight(100);        
  return myResponse;
}

class MyJSONRespone{

  private String name;

  private Integer width;

  private Integer Height;

  //setters and getters

}

如果您使用Maven，还要确保POM中具有正确的依赖关系：

    <!-- Jackson/JSON START -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.4.2</version>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.4.2</version>
    </dependency>

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.4.2</version>
    </dependency>
    <!-- Jackson/JSON END -->

spring mvc output in json format

1 个答案: