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我正在处理有时会发生变化的 json 数据。有时Segment只是一个列表，有时segment先是一个对象，然后是一个列表。我从一个 url 流式传输 json 数据，所以几天前我将它保存到一个 txt 文件中，这就是为什么今天的日期没有显示。编辑：更新了更改的 json 数据并添加了我拥有的所有片段。这是两个不同的 json 字符串： 这里的段只是一个列表

{
  "timetableresult": {
    "ttitem": [
      {
        "segment": [
          {
            "segmentid": {
              "mot": {
                "@displaytype": "B",
                "@type": "BLT",
                "#text": "Buss"
              },
              "carrier": {
                "name": "Vasttrafik",
                "url": "http://www.vasttrafik.se/",
                "id": 279,
                "number": 100
              }
            },
            "direction": "Goteborg Nils Ericsonterminal",
            "departure": {
              "location": {
                "@id": 7400300,
                "@x": 12.932004,
                "@y": 57.720838,
                "name": "Boras Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 20:10"
            },
            "arrival": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 21:10"
            }
          },
          {
            "segmentid": {
              "mot": {
                "@displaytype": "G",
                "@type": "G",
                "#text": "Gang"
              },
              "distance": 218
            },
            "departure": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 21:10"
            },
            "arrival": {
              "location": {
                "@id": 7400002,
                "@x": 11.973479,
                "@y": 57.708895,
                "name": "Goteborg Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 21:13"
            }
          }
        ]
      },
      {
        "segment": [
          {
            "segmentid": {
              "mot": {
                "@displaytype": "B",
                "@type": "BLT",
                "#text": "Buss"
              },
              "carrier": {
                "name": "Vasttrafik",
                "url": "http://www.vasttrafik.se/",
                "id": 279,
                "number": 100
              }
            },
            "direction": "Goteborg Nils Ericsonterminal",
            "departure": {
              "location": {
                "@id": 7400300,
                "@x": 12.932004,
                "@y": 57.720838,
                "name": "Boras Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 20:40"
            },
            "arrival": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 21:40"
            }
          },
          {
            "segmentid": {
              "mot": {
                "@displaytype": "G",
                "@type": "G",
                "#text": "Gang"
              },
              "distance": 218
            },
            "departure": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 21:40"
            },
            "arrival": {
              "location": {
                "@id": 7400002,
                "@x": 11.973479,
                "@y": 57.708895,
                "name": "Goteborg Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 21:43"
            }
          }
        ]
      },
      {
        "segment": [
          {
            "segmentid": {
              "mot": {
                "@displaytype": "B",
                "@type": "BXB",
                "#text": "Expressbuss"
              },
              "carrier": {
                "name": "Swebus",
                "url": "http://www.swebus.se/",
                "id": 690,
                "number": 830
              }
            },
            "direction": "Goteborg Nils Ericsonterminal",
            "remarks": {
              "remark": [
                {
                  "@id": "A7",
                  "#text": "Djur ej tillatet"
                },
                {
                  "@id": "AA",
                  "#text": "Endast 2 klass"
                }
              ]
            },
            "departure": {
              "location": {
                "@id": 7400300,
                "@x": 12.932004,
                "@y": 57.720838,
                "name": "Boras Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 20:50"
            },
            "arrival": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 21:55"
            }
          },
          {
            "segmentid": {
              "mot": {
                "@displaytype": "G",
                "@type": "G",
                "#text": "Gang"
              },
              "distance": 218
            },
            "departure": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 21:55"
            },
            "arrival": {
              "location": {
                "@id": 7400002,
                "@x": 11.973479,
                "@y": 57.708895,
                "name": "Goteborg Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 21:58"
            }
          }
        ]
      },
      {
        "segment": [
          {
            "segmentid": {
              "mot": {
                "@displaytype": "B",
                "@type": "BLT",
                "#text": "Buss"
              },
              "carrier": {
                "name": "Vasttrafik",
                "url": "http://www.vasttrafik.se/",
                "id": 279,
                "number": 100
              }
            },
            "direction": "Goteborg Nils Ericsonterminal",
            "departure": {
              "location": {
                "@id": 7400300,
                "@x": 12.932004,
                "@y": 57.720838,
                "name": "Boras Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 21:10"
            },
            "arrival": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 22:10"
            }
          },
          {
            "segmentid": {
              "mot": {
                "@displaytype": "G",
                "@type": "G",
                "#text": "Gang"
              },
              "distance": 218
            },
            "departure": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 22:10"
            },
            "arrival": {
              "location": {
                "@id": 7400002,
                "@x": 11.973479,
                "@y": 57.708895,
                "name": "Goteborg Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 22:13"
            }
          }
        ]
      },
      {
        "segment": [
          {
            "segmentid": {
              "mot": {
                "@displaytype": "B",
                "@type": "BLT",
                "#text": "Buss"
              },
              "carrier": {
                "name": "Vasttrafik",
                "url": "http://www.vasttrafik.se/",
                "id": 279,
                "number": 100
              }
            },
            "direction": "Goteborg Nils Ericsonterminal",
            "departure": {
              "location": {
                "@id": 7400300,
                "@x": 12.932004,
                "@y": 57.720838,
                "name": "Boras Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 21:40"
            },
            "arrival": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 22:40"
            }
          },
          {
            "segmentid": {
              "mot": {
                "@displaytype": "G",
                "@type": "G",
                "#text": "Gang"
              },
              "distance": 218
            },
            "departure": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 22:40"
            },
            "arrival": {
              "location": {
                "@id": 7400002,
                "@x": 11.973479,
                "@y": 57.708895,
                "name": "Goteborg Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 22:43"
            }
          }
        ]
      },
      {
        "segment": [
          {
            "segmentid": {
              "mot": {
                "@displaytype": "B",
                "@type": "BLT",
                "#text": "Buss"
              },
              "carrier": {
                "name": "Vasttrafik",
                "url": "http://www.vasttrafik.se/",
                "id": 279,
                "number": 101
              }
            },
            "direction": "Goteborg Nils Ericsonterminal",
            "departure": {
              "location": {
                "@id": 7400300,
                "@x": 12.932004,
                "@y": 57.720838,
                "name": "Boras Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 21:55"
            },
            "arrival": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 23:01"
            }
          },
          {
            "segmentid": {
              "mot": {
                "@displaytype": "G",
                "@type": "G",
                "#text": "Gang"
              },
              "distance": 218
            },
            "departure": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 23:01"
            },
            "arrival": {
              "location": {
                "@id": 7400002,
                "@x": 11.973479,
                "@y": 57.708895,
                "name": "Goteborg Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 23:04"
            }
          }
        ]
      },
      {
        "segment": [
          {
            "segmentid": {
              "mot": {
                "@displaytype": "B",
                "@type": "BLT",
                "#text": "Buss"
              },
              "carrier": {
                "name": "Vasttrafik",
                "url": "http://www.vasttrafik.se/",
                "id": 279,
                "number": 100
              }
            },
            "direction": "Goteborg Nils Ericsonterminal",
            "departure": {
              "location": {
                "@id": 7400300,
                "@x": 12.932004,
                "@y": 57.720838,
                "name": "Boras Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 22:10"
            },
            "arrival": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 23:10"
            }
          },
          {
            "segmentid": {
              "mot": {
                "@displaytype": "G",
                "@type": "G",
                "#text": "Gang"
              },
              "distance": 218
            },
            "departure": {
              "location": {
                "@id": 7420483,
                "@x": 11.971856,
                "@y": 57.710275,
                "name": "Goteborg Nils Ericsonterminal"
              },
              "datetime": "2012-11-26 23:10"
            },
            "arrival": {
              "location": {
                "@id": 7400002,
                "@x": 11.973479,
                "@y": 57.708895,
                "name": "Goteborg Centralstation",
                "stationinfo": {
                  "@exists": "true"
                }
              },
              "datetime": "2012-11-26 23:13"
            }
          }
        ]
      }
    ]
  }
}

由于字符有限，继续显示得稍微靠下一点...

4

1 回答 1

0

只需使用 Json 节点即可：

public class Demo {

    public static void main(String[] args) throws IOException {
        String json = "{\n" +
                "  \"timetableresult\": {\n" +
                "    \"ttitem\": [\n" +
                "      {\n" +
                "        \"segmentId\": 1,\n" +
                "        \"value\": \"someVal\"\n" +
                "      },\n" +
                "      {\n" +
                "        \"segmentId\": 2,\n" +
                "        \"value\": \"someAnotherVal\"\n" +
                "      }\n" +
                "    ]\n" +
                "  }\n" +
                "}";

        ObjectMapper mapper = new ObjectMapper();
        JsonNode node = mapper.readValue(json, JsonNode.class);
        JsonNode jsonArray = node.get("timetableresult").get("ttitem");
        System.out.println(jsonArray.get(1)); //will return null if it couldn't find
    }
}

它将自动创建一个包含所有需要的 json 映射的树结构。

Jackson 的最佳 maven 依赖项：

<dependency>
        <groupId>com.fasterxml.jackson.datatype</groupId>
        <artifactId>jackson-datatype-jsr310</artifactId>
        <version>${jackson.version}</version>
</dependency>

文档： http: //fasterxml.github.io/jackson-databind/javadoc/2.0.0/com/fasterxml/jackson/databind/JsonNode.html

于 2016-10-11T15:45:13.883 回答