JsonPath如何获取JSON数据中的值

场景: 发送接口请求后，得到请求结果值是Json数据， 需要从Json数据信息中提取字段值。

响应值字符与字符之间有空格，导致用正则表达式方法提取比较麻烦，于是用java的JsonPath方法提取快速方便好用,根据JSON路径去取。

Json数据： 需要提取FILE 字段对应的值。

{
   "data" : {
      "testCaseData" : [
         {
            "agent_version" : "9.7.0.2225",
            "android_id" : "e3d699cf01620531",
            "asset_number" : "",
            "FILE" : "./ wwwccko(33)  .zip",
            "noncomp_reason" : "",
         },
         {
            "agent_version" : "2.0.0.1518",
            "android_id" : "",
            "asset_number" : "",
             "FILE" : "./XXXX(22)  .zip",
            "noncomp_reason" : "",
         }
      ],
      "total_count" : 2
   },
   "error_code" : 1,
   "message" : "Success",
   "timestamp" : 1504765848
}

解决方法：

package com.app.test;

import java.util.LinkedHashMap;
import net.minidev.json.JSONArray;
import com.jayway.jsonpath.JsonPath;
import com.jayway.jsonpath.Predicate;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;

public class TestJsonPath {

    public static void main(String[] args) {
        String charset = "utf-8";
        File file = new File("D:\\Work_Report\\JSON2.txt");
        long fileByteLength = file.length();
        byte[] content = new byte[(int) fileByteLength];
        FileInputStream fileInputStream = null;
        try {
            fileInputStream = new FileInputStream(file);
            fileInputStream.read(content);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        String str = null;
        try {
            str = new String(content, charset);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        System.out.println(str);
        readjson(str, "$.data.testCaseData[0].FILE");
        System.out.println(readjson(str, "$.data.testCaseData[0].FILE"));
    }

    public static String readjson(String json, String jsonPath) {
        try {
            Object value = JsonPath.read(json, jsonPath, new Predicate[0]);
            if (value instanceof Integer) {
                return value.toString();
            } else if (value instanceof String) {
                return value.toString();
            } else if (value instanceof Boolean) {
                return value.toString();
            } else if (value instanceof JSONArray) {
                JSONArray arr = (JSONArray) value;
                if (!arr.isEmpty()) {
                    return arr.toJSONString();
                } else
                    return "";
            } else if (value instanceof LinkedHashMap) {
                return value.toString();
            } else if (value instanceof Float) {
                return value.toString();
            } else {
                return value.toString();
            }
        } catch (Exception e) {
            return "pathnotfound";
        }
    }
}

注: JsonPath固定语法:   $.XX.XX[索引].对象key

依赖包

<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>2.4.0</version>
</dependency>

String rep.jsonpath.result;
rep=repv.getResponseDataAsString();
jsonpath = "$.data.device[1].version
result = readjson(pre,jsonpath)
vars.put("XX",result)

工具类:

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.LinkedHashMap;
import net.minidev.json.JSONArray;
import com.jayway.jsonpath.JsonPath;
import com.jayway.jsonpath.Predicate;

public class Utils {

    public static String readJson(String filePath) {
        String charset = "utf-8";
        File file = new File(filePath);
        long fileByteLength = file.length();
        byte[] content = new byte[(int) fileByteLength];
        FileInputStream fileInputStream = null;
        try {
            fileInputStream = new FileInputStream(file);
            fileInputStream.read(content);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                fileInputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        String str = null;
        try {
            str = new String(content, charset);
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return str;
    }

    public static String readjson(String json, String jsonPath) {
        try {
            Object value = JsonPath.read(json, jsonPath, new Predicate[]);
            if (value instanceof Integer) {
                return value.toString();
            } else if (value instanceof String) {
                return value.toString();
            } else if (value instanceof Boolean) {
                return value.toString();
            } else if (value instanceof JSONArray) {
                JSONArray arr = (JSONArray) value;
                if (!arr.isEmpty()) {
                    return arr.toJSONString();
                } else
                    return "";
            } else if (value instanceof LinkedHashMap) {
                return value.toString();
            } else if (value instanceof Float) {
                return value.toString();
            } else {
                return value.toString();
            }
        } catch (Exception e) {
            return "pathnotfound";
        }
    }

}