json路径解析

JsonPath

JsonPath:从多层嵌套Json中解析所需要的值

<!-- https://mvnrepository.com/artifact/com.jayway.jsonpath/json-path -->
<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>2.4.0</version>
</dependency>

public class JsonUtilTest extends CommonForTest {

  String json = "{\"code\":200,\"msg\":\"ok\",\"list\":[{\"id\":20,\"no\":\"1000020\",\"items\":[{\"name\":\"n1\",\"price\":21,\"infos\":{\"feature\":\"\"}}]}],\"metainfo\":{\"total\":20,\"info\":{\"owner\":\"qinshu\",\"parts\":[{\"count\":13,\"time\":{\"start\":1230002456,\"end\":234001234}}]}}}";

  // 常用的 Json Path 可以缓存起来重用，类似正则里的 Pattern p = Pattern.compile('regexString')
  JsonPath codePath = JsonPath.compile("$.code");
  JsonPath totalPath = JsonPath.compile("$.metainfo.total");

  @Test
  public void testReadVal() {

    eq(null, JsonUtil.readVal(null, "code"));
    eq(null, JsonUtil.readVal(json, null));
    eq("200", JsonUtil.readVal(json, "code"));
    eq("20", JsonUtil.readVal(json, "metainfo.total"));
    eq("qinshu", JsonUtil.readVal(json, "metainfo.info.owner"));
    eq(null, JsonUtil.readVal("invalid json", "code"));
    eq(null,JsonUtil.readVal(json, "metainfo.extra.feature"));

    eq(null, JsonUtil.readValUsingJsonPath(null, "code"));
    eq(null, JsonUtil.readValUsingJsonPath(json, null));
    eq("200", JsonUtil.readValUsingJsonPath(json, "code"));
    eq("20", JsonUtil.readValUsingJsonPath(json, "metainfo.total"));
    eq("qinshu", JsonUtil.readValUsingJsonPath(json, "metainfo.info.owner"));
    eq(null, JsonUtil.readValUsingJsonPath("invalid json", "code"));
    eq(null,JsonUtil.readValUsingJsonPath(json, "metainfo.extra.feature"));

    eq(200, codePath.read(json));
    eq(20, totalPath.read(json));
    eq("qinshu", JsonPath.read(json, "$.metainfo.info.owner"));
    eq("n1", JsonPath.read(json, "$.list[0].items[0].name"));
    eq(13, JsonPath.read(json, "$.metainfo.info.parts[0].count"));

  }

}