类似GraphQL，自定义json输出，Kotlin实现

2019独角兽企业重金招聘Python工程师标准>>>

第一次见GraphQL的时候是去年&＃xff0c;完全被惊呆了&＃xff0c;心想这么牛逼&＃xff0c;前台想要什么就可以拿到什么数据&＃xff0c;不想要的完全可以不获取&＃xff0c;之后就开始尝试使用GraphQL&＃xff0c;然后发现入门失败。

但是自己又有这方面的需求&＃xff0c;比如有一个数据格式&＃xff08;暂定用户信息&＃xff09;&＃xff0c;有多个接口需要获取它的信息&＃xff0c;而且每个接口的需求不一样&＃xff0c;也可能后端为了限制某些字段不给某个接口返回。

例如&＃xff1a;用户&＃xff08;id&＃xff0c;姓名&＃xff0c;年龄&＃xff0c;爱好&＃xff0c;出生日期&＃xff0c;身份证&＃xff0c;密码&＃xff0c;头像&＃xff09;

A接口&＃xff1a;只需要&＃xff08;姓名、年龄、爱好&＃xff09;&＃xff0c;其他信息无权限获取

B接口&＃xff1a;需要&＃xff08;姓名、出生日期、身份证、头像&＃xff09;&＃xff0c;其他信息并不关心&＃xff0c;且密码无法获取

C接口&＃xff1a;有权限获取全部信息&＃xff0c;但又不需要全部信息

当遇到这种情况的时候基础的json可以较方便的解决&＃xff0c;但是如果遇到联级的信息呢&＃xff1f;&＃xff1f;

比如&＃xff1a;国家&＃xff08;名称&＃xff0c;地区&＃xff08;名称&＃xff0c;市&＃xff08;名称&＃xff0c;县....&＃xff09;&＃xff09;&＃xff09;这样联级的信息&＃xff0c;就难搞了。

因此需要GraphQL这样的工具&＃xff0c;直接写一个字符串去过滤出需要的数据&＃xff08;{country{name,Area{name,city{name,county}}}}&＃xff09;只通过这个字符串就过滤出我们需要的json数据。

下面进入代码阶段&＃xff08;完整的代码在最后面贴出来&＃xff09;

开发语言&＃xff1a;Kotlin

开发平台&＃xff1a;Windows

开发工具&＃xff1a;Idea

完整代码&＃xff1a;https://gitee.com/houkunlin/goour-utils/blob/master/src/main/kotlin/cn/goour/kotlin/tools/MapTools.kt

第一步&＃xff1a;写一个字符串解析方法&＃xff0c;解析过滤字符串&＃xff0c;解析成map键值对形式&＃xff0c;key为字段信息&＃xff0c;value为子类嵌套过滤字符串

private fun getKeyMap(key: String): HashMap {val keyMap &＃61; hashMapOf()var lastIndex &＃61; 0var endIndex &＃61; 0var left &＃61; 0key.forEachIndexed { index, c ->when (c) {&＃39;,&＃39; -> {if (left &＃61;&＃61; 0 && lastIndex {if (left &＃61;&＃61; 0) {endIndex &＃61; index}&＃43;&＃43;left}&＃39;}&＃39; -> {if (--left &＃61;&＃61; 0) {keyMap[key.substring(lastIndex, endIndex).replace(",", "")] &＃61; key.substring(endIndex &＃43; 1, index)lastIndex &＃61; index &＃43; 2}}}if (index &＃61;&＃61; key.lastIndex && lastIndex }

第二步&＃xff1a;就是开始对bean的字段进行过滤了&＃xff0c;返回一个map&＃xff0c;key为字段信息&＃xff0c;value为字段值

fun Any.toMapInclude(key: String): Map {val keyMap &＃61; getKeyMap(key)val fields &＃61; this.javaClass.declaredFieldsval map &＃61; hashMapOf()fields.forEach {it.isAccessible &＃61; trueif (keyMap.contains(it.name) && it.name !&＃61; "Companion") {val value &＃61; keyMap[it.name]if (value !&＃61; null) {val obj &＃61; it.get(this)when {Iterable::class.java.isInstance(obj) -> {val list &＃61; arrayListOf()obj as Collection<*>obj.forEach {if (it !&＃61; null) {list &＃43;&＃61; it.toMapInclude(value)}}map[it.name] &＃61; list}it.type.isArray -> {val list &＃61; arrayListOf()obj as Array<*>obj.forEach {if (it !&＃61; null) {list &＃43;&＃61; it.toMapInclude(value)}}map[it.name] &＃61; list}else -> map[it.name] &＃61; obj.toMapInclude(value)}} else {val obj &＃61; it.get(this)when {it.type.isArray -> {obj as Array<*>map[it.name] &＃61; obj.toList()}else -> map[it.name] &＃61; it.get(this)}}}}return map }

OK&＃xff0c;完工&＃xff0c;之后开始测试跑一下

下面贴另一份测试结果

fun main(args: Array) {val g &＃61; Country(name &＃61; "中国",area &＃61; Area(name &＃61; "广西", gps &＃61; arrayOf("1.x", "2.x"),city &＃61; City(name &＃61; "桂林",county &＃61; listOf(County(name &＃61; "测试县城1", gps &＃61; arrayOf("1.x", "2.x")),County(name &＃61; "测试县城2", gps &＃61; arrayOf("11.x", "22.x"))))))val str &＃61; "name,area{name,gps,city{name,county{name}}}"println(g.toMapInclude(str))println(g.toMapInclude(str).toJsonString())var start &＃61; System.currentTimeMillis()for (i in 1..100000) {g.toMap()}var end &＃61; System.currentTimeMillis()println("转map耗时&＃xff1a;${(end - start) / 1000.0}s")start &＃61; System.currentTimeMillis()for (i in 1..100000) {g.toMapInclude(str)}end &＃61; System.currentTimeMillis()println("过滤耗时&＃xff1a;${(end - start) / 1000.0}s")start &＃61; System.currentTimeMillis()for (i in 1..100000) {JSONObject.toJSON(g)}end &＃61; System.currentTimeMillis()println("json耗时&＃xff1a;${(end - start) / 1000.0}s")start &＃61; System.currentTimeMillis()for (i in 1..100000) {g.toMapInclude(str).toJsonString()}end &＃61; System.currentTimeMillis()println("转map转json耗时&＃xff1a;${(end - start) / 1000.0}s") } /* 运行结果电脑处理器&＃xff1a;AMD A12-9700P 2.50GHz 内存RAM&＃xff1a;8.00GB&＃xff08;7.46GB可用&＃xff09; {area&＃61;{city&＃61;{name&＃61;桂林, county&＃61;[{name&＃61;测试县城1}, {name&＃61;测试县城2}]}, name&＃61;广西, gps&＃61;[1.x, 2.x]}, name&＃61;中国} {"area":{"city":{"name":"桂林","county":[{"name":"测试县城1"},{"name":"测试县城2"}]},"name":"广西","gps":["1.x","2.x"]},"name":"中国"} 转map耗时&＃xff1a;0.097s 过滤耗时&＃xff1a;1.213s json耗时&＃xff1a;1.092s 转map转json耗时&＃xff1a;2.074s */

下面贴全部完整的代码

package cn.goour.kotlin.toolsimport com.alibaba.fastjson.JSONObjectfun Any.toMap(): Map {val fields &＃61; this.javaClass.declaredFieldsval map &＃61; hashMapOf()fields.forEach {it.isAccessible &＃61; trueif (it.name !&＃61; "Companion") {map[it.name] &＃61; it.get(this)} // println(it.name &＃43; " " &＃43; it.type.name &＃43; " " &＃43; it.get(this))}return map }private fun getKeyMap(key: String): HashMap { // println(key)val keyMap &＃61; hashMapOf()var lastIndex &＃61; 0var endIndex &＃61; 0var left &＃61; 0key.forEachIndexed { index, c ->// println("$index &＃61; $c")when (c) {&＃39;,&＃39; -> {if (left &＃61;&＃61; 0 && lastIndex // println("$lastIndex -- $endIndex") // println("${key.substring(lastIndex, endIndex)} -- null")keyMap[key.substring(lastIndex, endIndex).replace(",", "")] &＃61; nulllastIndex &＃61; index &＃43; 1}}&＃39;{&＃39; -> {if (left &＃61;&＃61; 0) {endIndex &＃61; index}&＃43;&＃43;left}&＃39;}&＃39; -> {if (--left &＃61;&＃61; 0) { // println("$lastIndex -- $endIndex -- $index") // println("${key.substring(lastIndex, endIndex)} -- ${key.substring(endIndex &＃43; 1, index)}")keyMap[key.substring(lastIndex, endIndex).replace(",", "")] &＃61; key.substring(endIndex &＃43; 1, index)lastIndex &＃61; index &＃43; 2}}}if (index &＃61;&＃61; key.lastIndex && lastIndex // println("$lastIndex -- $endIndex") // println("${key.substring(lastIndex)} -- null")keyMap[key.substring(lastIndex).replace(",", "")] &＃61; null}}return keyMap }fun Any.toMapInclude(key: String): Map { // println(key)val keyMap &＃61; getKeyMap(key)val fields &＃61; this.javaClass.declaredFieldsval map &＃61; hashMapOf()fields.forEach {it.isAccessible &＃61; trueif (keyMap.contains(it.name) && it.name !&＃61; "Companion") {val value &＃61; keyMap[it.name]if (value !&＃61; null) {val obj &＃61; it.get(this)when {Iterable::class.java.isInstance(obj) -> {val list &＃61; arrayListOf()obj as Collection<*>obj.forEach {if (it !&＃61; null) {list &＃43;&＃61; it.toMapInclude(value)}}map[it.name] &＃61; list}it.type.isArray -> {val list &＃61; arrayListOf()obj as Array<*>obj.forEach {if (it !&＃61; null) {list &＃43;&＃61; it.toMapInclude(value)}}map[it.name] &＃61; list}else -> map[it.name] &＃61; obj.toMapInclude(value)}} else {val obj &＃61; it.get(this)when {it.type.isArray -> {obj as Array<*>map[it.name] &＃61; obj.toList()}else -> map[it.name] &＃61; it.get(this)}}}}return map }fun Map<*, *>.toJsonString(dateFormat: String &＃61; "yyyy-MM-dd HH:mm:ss"): String {return JSONObject.toJSONStringWithDateFormat(this, dateFormat) }fun main(args: Array) {val g &＃61; Country(name &＃61; "中国",area &＃61; Area(name &＃61; "广西", gps &＃61; arrayOf("1.x", "2.x"),city &＃61; City(name &＃61; "桂林",county &＃61; listOf(County(name &＃61; "测试县城1", gps &＃61; arrayOf("1.x", "2.x")),County(name &＃61; "测试县城2", gps &＃61; arrayOf("11.x", "22.x"))))))val str &＃61; "name,area{name,gps,city{name,county{name}}}"println(g.toMapInclude(str))println(g.toMapInclude(str).toJsonString())var start &＃61; System.currentTimeMillis()for (i in 1..100000) {g.toMap()}var end &＃61; System.currentTimeMillis()println("转map耗时&＃xff1a;${(end - start) / 1000.0}s")start &＃61; System.currentTimeMillis()for (i in 1..100000) {g.toMapInclude(str)}end &＃61; System.currentTimeMillis()println("过滤耗时&＃xff1a;${(end - start) / 1000.0}s")start &＃61; System.currentTimeMillis()for (i in 1..100000) {JSONObject.toJSON(g)}end &＃61; System.currentTimeMillis()println("json耗时&＃xff1a;${(end - start) / 1000.0}s")start &＃61; System.currentTimeMillis()for (i in 1..100000) {g.toMapInclude(str).toJsonString()}end &＃61; System.currentTimeMillis()println("转map转json耗时&＃xff1a;${(end - start) / 1000.0}s") }data class Country(var name: String,var area: Area? &＃61; null )data class Area(var name: String,var gps: Array? &＃61; null,var city: City? &＃61; null )data class City(var name: String,var county: List )data class County(var name: String,var gps: Array? &＃61; null )