Elasticsearch JSON Java对象 相互转换（XContentBuilder，XContentParser）

采用Elasticsearch Client SDK 实现 JSON 字符串 和 Java对象的相互转换

public static void main(String[] args) throws IOException {
        //Object to JSON String
        Map phases = new HashMap<>();
        Map hotActions = new HashMap<>();
        hotActions.put(RolloverAction.NAME, new RolloverAction(
            new ByteSizevalue(50, ByteSizeUnit.GB), null, null));
        phases.put("hot", new Phase("hot", Timevalue.ZERO, hotActions));

        Map deleteActions =
            Collections.singletonMap(DeleteAction.NAME, new DeleteAction());
        phases.put("delete", new Phase("delete",
            new Timevalue(90, TimeUnit.DAYS), deleteActions));

        LifecyclePolicy policy = new LifecyclePolicy("my_policy",
            phases);
        PutLifecyclePolicyRequest request =
            new PutLifecyclePolicyRequest(policy);
        XContentBuilder xContentBuilder = JsonXContent.contentBuilder();
        request.toXContent(xContentBuilder, ToXContent.EMPTY_PARAMS);
        String json = Strings.toString(request, true, true);
        System.out.println(json);




        //JSON String  to Object
        String json2 = "{n"
            + "    "phases" : {n"
            + "      "hot" : {n"
            + "        "min_age" : "0ms",n"
            + "        "actions" : {n"
            + "          "rollover" : {n"
            + "            "max_size" : "50gb"n"
            + "          }n"
            + "        }n"
            + "      },n"
            + "      "delete" : {n"
            + "        "min_age" : "90d",n"
            + "        "actions" : {n"
            + "          "delete" : { }n"
            + "        }n"
            + "      }n"
            + "    }n"
            + "  }";
            //根据解析的对象，设置不同的NamedXContentRegistry
        final XContentParser parser = XContentType.JSON.xContent().createParser(new NamedXContentRegistry(new IndexLifecycleNamedXContentProvider().getNamedXContentParsers()),
            new DeprecationHandler() {
                @Override
                public void usedDeprecatedName(String usedName, String modernName) {
                }

                @Override
                public void usedDeprecatedField(String usedName, String replacedWith) {
                }
            }, json2);
        final LifecyclePolicy test_policy_name = LifecyclePolicy.parse(parser, "test_policy_name");
        test_policy_name.toXContent(xContentBuilder, ToXContent.EMPTY_PARAMS);
        System.out.println(Strings.toString(test_policy_name, true, true));
    }