【实用工具】解析JSON的利器JsonPath

项目地址

https://github.com/json-path/JsonPath

Maven依赖

        <dependency>
            <groupId>com.jayway.jsonpathgroupId>
            <artifactId>json-pathartifactId>
            <version>2.4.0version>
        dependency>

测试用例

可用于对json字符串的编辑，修改，删除

public class JsonPathTest {

    @Test
    public void t1() {
        String json = "{\n" +
                "    \"store\": {\n" +
                "        \"book\": [\n" +
                "            {\n" +
                "                \"category\": \"reference\",\n" +
                "                \"author\": \"Nigel Rees\",\n" +
                "                \"title\": \"Sayings of the Century\",\n" +
                "                \"price\": 8.95\n" +
                "            },\n" +
                "            {\n" +
                "                \"category\": \"fiction\",\n" +
                "                \"author\": \"Evelyn Waugh\",\n" +
                "                \"title\": \"Sword of Honour\",\n" +
                "                \"price\": 12.99\n" +
                "            },\n" +
                "            {\n" +
                "                \"category\": \"fiction\",\n" +
                "                \"author\": \"Herman Melville\",\n" +
                "                \"title\": \"Moby Dick\",\n" +
                "                \"isbn\": \"0-553-21311-3\",\n" +
                "                \"price\": 8.99\n" +
                "            },\n" +
                "            {\n" +
                "                \"category\": \"fiction\",\n" +
                "                \"author\": \"J. R. R. Tolkien\",\n" +
                "                \"title\": \"The Lord of the Rings\",\n" +
                "                \"isbn\": \"0-395-19395-8\",\n" +
                "                \"price\": 22.99\n" +
                "            }\n" +
                "        ],\n" +
                "        \"bicycle\": {\n" +
                "            \"color\": \"red\",\n" +
                "            \"price\": 19.95\n" +
                "        }\n" +
                "    },\n" +
                "    \"expensive\": 10\n" +
                "}";
        String newJson = JsonPath.parse(json).set("$.store.book[0].title", "lucas").jsonString();
        System.out.println(newJson);
        System.out.println("===");
        String newJson1 = JsonPath.parse(newJson).put("$.store.book[0]", "hello", "你好").jsonString();
        System.out.println(newJson1);
        System.out.println("===");
        String newJson2 = JsonPath.parse(newJson1).delete("$.store.book[0].hello").jsonString();
        System.out.println(newJson2);

    }
}

开源项目的应用

在apache shenyu项目中ModifyResponsePlugin有用到JsonPath

/**
 * ModifyResponse plugin.
 */
public class ModifyResponsePlugin extends AbstractShenyuPlugin {

    private static final Logger LOG = LoggerFactory.getLogger(ModifyResponsePlugin.class);

    @Override
    protected Mono<Void> doExecute(final ServerWebExchange exchange, final ShenyuPluginChain chain, final SelectorData selector, final RuleData rule) {
        ShenyuContext shenyuContext = exchange.getAttribute(Constants.CONTEXT);
        assert shenyuContext != null;
        ModifyResponseRuleHandle ruleHandle = ModifyResponsePluginDataHandler.CACHED_HANDLE.get().obtainHandle(CacheKeyUtils.INST.getKey(rule));
        if (Objects.isNull(ruleHandle)) {
            return chain.execute(exchange);
        }
        return chain.execute(exchange.mutate()
                .response(new ModifyResponseDecorator(exchange, ruleHandle)).build());
    }

    static class ModifyResponseDecorator extends ServerHttpResponseDecorator {

        private final ServerWebExchange exchange;

        private final ModifyResponseRuleHandle ruleHandle;

        ModifyResponseDecorator(final ServerWebExchange exchange,
                                final ModifyResponseRuleHandle ruleHandle) {
            super(exchange.getResponse());
            this.exchange = exchange;
            this.ruleHandle = ruleHandle;
        }

        @Override
        @NonNull
        public Mono<Void> writeWith(@NonNull final Publisher<? extends DataBuffer> body) {
            ClientResponse clientResponse = this.buildModifiedResponse(body);
            Mono<byte[]> modifiedBody = clientResponse.bodyToMono(byte[].class)
                    .flatMap(originalBody -> Mono.just(modifyBody(originalBody)));
            return ResponseUtils.writeWith(clientResponse, this.exchange, modifiedBody, byte[].class);
        }

        private byte[] modifyBody(final byte[] responseBody) {
            try {
                String bodyStr = modifyBody(new String(responseBody, StandardCharsets.UTF_8));
                LOG.info("the body string {}", bodyStr);
                return bodyStr.getBytes(StandardCharsets.UTF_8);
            } catch (Exception e) {
                LOG.error("modify response error", e);
                throw new ShenyuException(String.format("response modify failure. %s", e.getLocalizedMessage()));
            }
        }

        private String modifyBody(final String jsonValue) {
            DocumentContext context = JsonPath.parse(jsonValue);
            if (CollectionUtils.isNotEmpty(this.ruleHandle.getAddBodyKeys())) {
                this.ruleHandle.getAddBodyKeys().forEach(info -> context.put(info.getPath(), info.getKey(), info.getValue()));
            }
            if (CollectionUtils.isNotEmpty(this.ruleHandle.getReplaceBodyKeys())) {
                this.ruleHandle.getReplaceBodyKeys().forEach(info -> context.renameKey(info.getPath(), info.getKey(), info.getValue()));
            }
            if (CollectionUtils.isNotEmpty(this.ruleHandle.getRemoveBodyKeys())) {
                this.ruleHandle.getRemoveBodyKeys().forEach(context::delete);
            }
            return context.jsonString();
        }
    }
}