如果項目需求是從某些復雜的json里面取值進行計算,用jsonpath+IK(ik-expression)來處理十分方便,jsonpath用來取json里面的值然后用IK自帶的函數進行計算,如果是特殊的計算那就自定義IK方法搞定,配置化很方便.
下面簡單介紹下jsonpath的使用方法,主要測試都在JsonPathDemo類里面:
下面是一個簡單的java項目demo:
注意: 其中他的max,min,avg,stddev函數只能類似于如下處理:
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//正確寫法 但是感覺很雞肋context.read("$.avg($.result.records[0].loan_type,$.result.records[1].loan_type,$.result.records[2].loan_type)"); |
不能傳入list 感覺比較雞肋,如果傳入list 他會報錯(如下錯誤寫法):
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//這樣會報錯Object maxV = context.read("$.max($.result.records[*].loan_type)");//這樣也會報錯Object maxV = context.read("$.result.records[*].loan_type.max()");//如果json文件中是這樣:"loan_type":"2",也會報錯,"loan_type":2 這樣才被認為是數字 |
報錯信息都一樣, 如下:
Exception in thread "main" com.jayway.jsonpath.JsonPathException: Aggregation function attempted to calculate value using empty array
JsonPathDemo是一個測試demo:
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public class JsonPathDemo { public static void main(String[] args) { String json = FileUtils.readFileByLines("demo.json"); ReadContext context = JsonPath.parse(json); //1 返回所有name List<String> names = context.read("$.result.records[*].name"); //["張三","李四","王五"] System.out.println(names); //2 返回所有數組的值 List<Map<String, String>> objs = context.read("$.result.records[*]"); //[{"name":"張三","pid":"500234199212121212","mobile":"18623456789","applied_at":"3","confirmed_at":"5","confirm_type":"overdue","loan_type":"1","test":"mytest","all":"2"},{"name":"李四","pid":"500234199299999999","mobile":"13098765432","applied_at":"1","confirmed_at":"","confirm_type":"overdue","loan_type":"3","all":"3"},{"name":"王五","pid":"50023415464654659","mobile":"1706454894","applied_at":"-1","confirmed_at":"","confirm_type":"overdue","loan_type":"3"}] System.out.println(objs); //3 返回第一個的name String name0 = context.read("$.result.records[0].name"); //張三 System.out.println(name0); //4 返回下標為0 和 2 的數組值 List<String> name0and2 = context.read("$.result.records[0,2].name"); //["張三","王五"] System.out.println(name0and2); //5 返回下標為0 到 下標為1的 的數組值 這里[0:2] 表示包含0 但是 不包含2 List<String> name0to2 = context.read("$.result.records[0:2].name"); //["張三","李四"] System.out.println(name0to2); //6 返回數組的最后兩個值 List<String> lastTwoName = context.read("$.result.records[-2:].name"); //["李四","王五"] System.out.println(lastTwoName); //7 返回下標為1之后的所有數組值 包含下標為1的 List<String> nameFromOne = context.read("$.result.records[1:].name"); //["李四","王五"] System.out.println(nameFromOne); //8 返回下標為3之前的所有數組值 不包含下標為3的 List<String> nameEndTwo = context.read("$.result.records[:3].name"); //["張三","李四","王五"] System.out.println(nameEndTwo); //9 返回applied_at大于等于2的值 List<Map<String, String>> records = context.read("$.result.records[?(@.applied_at >= '2')]"); //[{"name":"張三","pid":"500234199212121212","mobile":"18623456789","applied_at":"3","confirmed_at":"5","confirm_type":"overdue","loan_type":"1","test":"mytest","all":"2"}] System.out.println(records); //10 返回name等于李四的值 List<Map<String, String>> records0 = context.read("$.result.records[?(@.name == '李四')]"); //[{"name":"李四","pid":"500234199299999999","mobile":"13098765432","applied_at":"1","confirmed_at":"","confirm_type":"overdue","loan_type":"3"}] System.out.println(records0); //11 返回有test屬性的數組 List<Map<String, String>> records1 = context.read("$.result.records[?(@.test)]"); //[{"name":"張三","pid":"500234199212121212","mobile":"18623456789","applied_at":"3","confirmed_at":"5","confirm_type":"overdue","loan_type":"1","test":"mytest","all":"2"}] System.out.println(records1); //12 返回有test屬性的數組 List<String> list = context.read("$..all"); //["1","4","2","3"] System.out.println(list); //12 以當前json的某個值為條件查詢 這里ok為1 取出records數組中applied_at等于1的數組 List<String> ok = context.read("$.result.records[?(@.applied_at == $['ok'])]"); //["1","4","2","3"] System.out.println(ok); //13 正則匹配 List<String> regexName = context.read("$.result.records[?(@.pid =~ /.*999/i)]"); //[{"name":"李四","pid":"500234199299999999","mobile":"13098765432","applied_at":"1","confirmed_at":"","confirm_type":"overdue","loan_type":"3","all":"3"}] System.out.println(regexName); //14 多條件 List<String> mobile = context.read("$.result.records[?(@.all == '2' || @.name == '李四' )].mobile"); //["18623456789","13098765432"] System.out.println(mobile); //14 查詢數組長度 Integer length01 = context.read("$.result.records.length()"); //3 System.out.println(length01); //15 查詢list里面每個對象長度 List<Integer> length02 = context.read("$.result.records[?(@.all == '2' || @.name == '李四' )].length()"); //[9,8] System.out.println(length02); //16 最大值 Object maxV = context.read("$.max($.result.records[0].loan_type,$.result.records[1].loan_type,$.result.records[2].loan_type)"); //3.0 System.out.println(maxV); //17 最小值 Object minV = context.read("$.min($.result.records[0].loan_type,$.result.records[1].loan_type,$.result.records[2].loan_type)"); //1.0 System.out.println(minV); //18 平均值 double avgV = context.read("$.avg($.result.records[0].loan_type,$.result.records[1].loan_type,$.result.records[2].loan_type)"); //2.3333333333333335 System.out.println(avgV); //19 標準差 double stddevV = context.read("$.stddev($.result.records[0].loan_type,$.result.records[1].loan_type,$.result.records[2].loan_type)"); //0.9428090415820636 System.out.println(stddevV); //20 讀取一個不存在的 String haha = context.read("$.result.haha"); //拋出異常 //Exception in thread "main" com.jayway.jsonpath.PathNotFoundException: No results for path: $['result']['haha'] //at com.jayway.jsonpath.internal.path.EvaluationContextImpl.getValue(EvaluationContextImpl.java:133) //at com.jayway.jsonpath.JsonPath.read(JsonPath.java:187) //at com.jayway.jsonpath.internal.JsonContext.read(JsonContext.java:102) //at com.jayway.jsonpath.internal.JsonContext.read(JsonContext.java:89) //at cn.lijie.jsonpath.JsonPathDemo.main(JsonPathDemo.java:58) //at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) //at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) //at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) //at java.lang.reflect.Method.invoke(Method.java:498) //at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147) System.out.println(haha); }} |
pom文件引入:
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<dependency> <groupId>com.jayway.jsonpath</groupId> <artifactId>json-path</artifactId> <version>2.3.0</version></dependency> |
其中demo.json是一個測試json:
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{ "action": "/interface.service/xxx/queryBlackUserData", "all": "1", "result": { "count": 2, "tenant_count": 2, "records": [ { "name": "張三", "pid": "500234199212121212", "mobile": "18623456789", "applied_at": "3", "confirmed_at": "5", "confirm_type": "overdue", "loan_type": 1, "test": "mytest", "all": "2" }, { "name": "李四", "pid": "500234199299999999", "mobile": "13098765432", "applied_at": "1", "confirmed_at": "", "confirm_type": "overdue", "loan_type": 3, "all": "3" }, { "name": "王五", "pid": "50023415464654659", "mobile": "1706454894", "applied_at": "-1", "confirmed_at": "", "confirm_type": "overdue", "loan_type": 3 } ], "all": "4" }, "code": 200, "subtime": "1480495123550", "status": "success", "ok": 3} |
FileUtils類是用于讀取xx.json文件為字符串的json:
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public class FileUtils { /** * 以行為單位讀取文件，常用于讀面向行的格式化文件 */ public static String readFileByLines(String fileName) { File file = new File(fileName); BufferedReader reader = null; String str = ""; try { InputStream is = FileUtils.class.getClassLoader().getResourceAsStream(fileName); reader = new BufferedReader(new InputStreamReader(is)); String tempString = null; int line = 1; // 一次讀入一行，直到讀入null為文件結束 while ((tempString = reader.readLine()) != null) { // 顯示行號 str += tempString; } reader.close(); } catch (IOException e) { e.printStackTrace(); } finally { if (reader != null) { try { reader.close(); } catch (IOException e1) { } } } return str; }} |
補充：json接口測試的利器jsonpath
在測試REST接口的時候，經常要解析JSON，那么可以使用開源jsonpath進行，其中看網上看到相關的說法不錯的使用場景為：
1、接口關聯
也稱為關聯參數。在應用業務接口中，完成一個業務功能時，有時候一個接口可能不滿足業務的整個流程邏輯，需要多個接口配合使用，簡單的案例如：B接口的成功調用依賴于A接口，需要在A接口的響應數據（response)中拿到需要的字段，在調用B接口的時候，傳遞給B接口作為B接口請求參數，拿到后續響應的響應數據。
接口關聯通常可以使用正則表達式去提取需要的數據，但對于json這種簡潔、清晰層次結構、輕量級的數據交互格式，使用正則未免有點殺雞用牛刀的感覺(是的，因為我不擅長寫正則表達式)，我們需要更加簡單、直接的提取json數據的方式。
2、數據驗證
這里的數據驗證指的是對響應結果進行數據的校驗
接口自動化測試中，對于簡單的響應結果（json），可以直接和期望結果進行比對，判斷是否完全相等即可。
如 json {"status":1,"msg":"登錄成功"}
3、對于格式較復雜
尤其部分數據存在不確定性、會根據實際情況變化的響應結果，簡單的判斷是否完全相等（斷言）通常會失敗。
如：
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json {"status":1,"code":"10001","data":[{"id":1,"investId":"1","createTime":"2018-04-27 12:24:01","terms":"1","unfinishedInterest":"1.0","unfinishedPrincipal":"0","repaymentDate":"2018-05-27 12:24:01","actualRepaymentDate":null,"status":"0"},{"id":2,"investId":"1","createTime":"2018-04-27 12:24:01","terms":"2","unfinishedInterest":"1.0","unfinishedPrincipal":"0","repaymentDate":"2018-06-27 12:24:01","actualRepaymentDate":null,"status":"0"},{"id":3,"investId":"1","createTime":"2018-04-27 12:24:01","terms":"3","unfinishedInterest":"1.0","unfinishedPrincipal":"100.00","repaymentDate":"2018-07-27 12:24:01","actualRepaymentDate":null,"status":"0"}],"msg":"獲取信息成功"} |
上面的json結構嵌套了很多信息，完整的匹配幾乎不可能成功。比如其中的createTime信息，根據執行接口測試用例的時間每次都不一樣。同時這個時間是響應結果中較為次要的信息，在進行接口自動化測試時，是可以選擇被忽略的。
4、我們需要某種簡單的方法
能夠從json中提取出我們真正關注的信息（通常也被稱為關鍵信息）。
如提取出status的值為1，data數組中每個對象的investId都為1，data中第三個對象的unfinishedPrincipal值為100.00，只要這三個關鍵信息校驗通過，我們就認為響應結果沒有問題。
JSONPATH有點像XPATH了，語法規則小結下：
這里有個表格，說明JSONPath語法元素和對應XPath元素的對比。
| XPath | JSONPath | Description |
| / | $ | 表示根元素 |
| . | @ | 當前元素 |
| / | . or [] | 子元素 |
| .. | n/a | 父元素 |
| // | .. | 遞歸下降，JSONPath是從E4X借鑒的。 |
| * | * | 通配符，表示所有的元素 |
| @ | n/a | 屬性訪問字符 |
| [] | [] |
子元素操作符 |
| | | [,] |
連接操作符在XPath 結果合并其它結點集合。JSONP允許name或者數組索引。 |
| n/a | [start:end:step] |
數組分割操作從ES4借鑒。 |
| [] | ?() |
應用過濾表示式 |
| n/a | () |
腳本表達式，使用在腳本引擎下面。 |
| () | n/a | Xpath分組 |
下面是一個簡單的json數據結構代表一個書店（原始的xml文件是）
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{ "store": { "book": [ { "category": "reference", "author": "Nigel Rees", "title": "Sayings of the Century", "price": 8.95 }, { "category": "fiction", "author": "Evelyn Waugh", "title": "Sword of Honour", "price": 12.99 }, { "category": "fiction", "author": "Herman Melville", "title": "Moby Dick", "isbn": "0-553-21311-3", "price": 8.99 }, { "category": "fiction", "author": "J. R. R. Tolkien", "title": "The Lord of the Rings", "isbn": "0-395-19395-8", "price": 22.99 } ], "bicycle": { "color": "red", "price": 19.95 } }} |
| XPath | JSONPath | 結果 |
| /store/book/author | $.store.book[*].author |
書點所有書的作者 |
| //author | $..author |
所有的作者 |
| /store/* | $.store.* |
store的所有元素。所有的bookst和bicycle |
| /store//price | $.store..price |
store里面所有東西的price |
| //book[3] | $..book[2] |
第三個書 |
| //book[last()] | $..book[(@.length-1)] | 最后一本書 |
| //book[position()<3] |
$..book[0,1]
$..book[:2] |
前面的兩本書。 |
| //book[isbn] | $..book[?(@.isbn)] | 過濾出所有的包含isbn的書。 |
| //book[price<10] | $..book[?(@.price<10)] | 過濾出價格低于10的書。 |
| //* | $..* |
所有元素。 |
比如在單元測試MOCK中，就可以這樣使用：
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@RunWith(SpringRunner.class)@SpringBootTest@AutoConfigureMockMvc@ActiveProfiles("test")public class BookControllerTest { @Autowired private MockMvc mockMvc; @MockBean private BookRepository mockRepository; /* { "timestamp":"2019-03-05T09:34:13.280+0000", "status":400, "errors":["Author is not allowed.","Please provide a price","Please provide a author"] } */ //article : jsonpath in array @Test public void save_emptyAuthor_emptyPrice_400() throws Exception { String bookInJson = "{\"name\":\"ABC\"}"; mockMvc.perform(post("/books") .content(bookInJson) .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON)) .andDo(print()) .andExpect(status().isBadRequest()) .andExpect(jsonPath("$.timestamp", is(notNullValue()))) .andExpect(jsonPath("$.status", is(400))) .andExpect(jsonPath("$.errors").isArray()) .andExpect(jsonPath("$.errors", hasSize(3))) .andExpect(jsonPath("$.errors", hasItem("Author is not allowed."))) .andExpect(jsonPath("$.errors", hasItem("Please provide a author"))) .andExpect(jsonPath("$.errors", hasItem("Please provide a price"))); verify(mockRepository, times(0)).save(any(Book.class)); }} |
以上為個人經驗，希望能給大家一個參考，也希望大家多多支持服務器之家。如有錯誤或未考慮完全的地方，望不吝賜教。
原文鏈接：https://blog.csdn.net/qq_20641565/article/details/77162868
