使用JSLT进行对象转换
作者：互联网
一.介绍与使用
JSLT是一种完整的JSON查询和转换语言。git地址：https://github.com/schibsted/jslt
java中使用：
<dependency>
<groupId>com.schibsted.spt.data</groupId>
<artifactId>jslt</artifactId>
<version>0.1.11</version>
<scope>compile</scope>
</dependency>
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.schibsted.spt.data.jslt.Expression;
import com.schibsted.spt.data.jslt.Parser;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import java.io.IOException;
@Slf4j
public class JsltUtil {
/**
* 转换json字符串(忽略异常，当异常时返回null)
* @param jsltStr jslt表达式
* @param inputStr json字符串入参
* @return
*/
public static String jsonAdapt(String jsltStr, String inputStr) {
try {
return jsonAdapt(jsltStr, inputStr, true);
} catch (Exception e) {
e.printStackTrace();
log.error("jsonAdapt error jsltStr={},inputStr={}", jsltStr, inputStr, e);
}
return null;
}
/**
* 转换json字符串
* @param jsltStr jslt表达式
* @param inputStr json字符串入参
* @param ignoreException 是否忽略异常 如果为ture，出现异常后返回null
* @return
*/
public static String jsonAdapt(String jsltStr, String inputStr, boolean ignoreException) throws IOException {
if (StringUtils.isBlank(jsltStr) || StringUtils.isBlank(inputStr)) {
log.info("jsonAdapt param illegal");
return null;
}
try {
ObjectMapper mapper = new ObjectMapper();
JsonNode input = mapper.readTree(inputStr);
Expression jslt = Parser.compileString(jsltStr);
JsonNode output = jslt.apply(input);
return output.toString();
} catch (Exception e) {
log.error("jsonAdapt error jsltStr={},inputStr={}", jsltStr, inputStr, e);
if (!ignoreException) {
throw e;
}
}
return null;
}
}
二.常用转换场景示例
1.普通对象转换
// jslt表达式
// crowd 根据age进行if判断输出人群
{
"name":.name,
"age":.age,
"crowd":if(.age<18) "未成年" else if(.age<60) "成年人" else "老年人"
}
// 入参：
{
"name":"nameTest",
"age":10
}
// 结果：
{
"name" : "nameTest",
"age" : 10,
"crowd" : "未成年"
}
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2.子对象转换
// jslt表达式
// * : . 匹配输入对象中的所有键，除了那些已经指定的，并将它们复制到输出对象中；如果有部分字段不想全拷贝使用 ：* - bar, baz, quux : .
// 注意一点， * ： 这个语法必须在最后，否则会报错 子对象中，没效果 "extendMsg3":{*:.} 这个字段直接不输出(只有当对象名和入参的一样时，才能在嵌套中再用* ，eg："extendMsg":{*:.} 是生效的)
{
"extendMsg1":.extendMsg,
"extendMsg2":{"married2":.extendMsg.married},
*:.
}
// 入参：
{
"name":"nameTest",
"age":10,
"extendMsg":{"sex":"男","married":false,"education":"小学生"}
}
// 结果：
{
"extendMsg1" : {
"sex" : "男",
"married" : false,
"education" : "小学生"
},
"extendMsg2" : {
"married2" : false
},
"name" : "nameTest",
"age" : 10,
"extendMsg" : {
"sex" : "男",
"married" : false,
"education" : "小学生"
}
}
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3.子对象平铺展开/对象缩进 转换
// 展开
// jslt表达式
{
"sex":.extendMsg.sex,
"married":.extendMsg.married,
* - extendMsg:.
}
// 入参：
{
"name":"nameTest",
"age":10,
"extendMsg":{"sex":"男","married":false,"education":"小学生"}
}
// 结果：
{
"sex" : "男",
"married" : false,
"name" : "nameTest",
"age" : 10
}
// 缩进
// jslt表达式
{
"name":.name,
"age":.age,
"extendMsg":{"sex":.sex,"married":.married,"education":.education}
}
// 入参：
{
"name":"nameTest",
"age":10,
"sex":"男",
"married":false,
"education":"小学生"
}
// 结果：
{
"name" : "nameTest",
"age" : 10,
"extendMsg" : {
"sex" : "男",
"married" : false,
"education" : "小学生"
}
}
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4.集合转换
/** 把集合全部转换 */
// jslt表达式
[for(.) {*:.}]
// 入参：
[
{
"name":"nameTest",
"age":10,
"sex":"男",
"married":false,
"education":"小学生"
},
{
"name":"nameTest2",
"age":102,
"sex":"女",
"married":true,
"education":"女博士"
}
]
// 结果：
// 输出和入参相同
/** 集合部分转换 */
// jslt表达式
[for(.) {"name":.name,"age":.age,"test":"testxxx"}]
// 结果：
[ {
"name" : "nameTest",
"age" : 10,
"test" : "testxxx"
}, {
"name" : "nameTest2",
"age" : 102,
"test" : "testxxx"
} ]
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5.复杂对象（分页为例）转换
/** 1.复杂组合=基础+集合 转换；2.haveNextPaga 举例变量计算 */
// jslt表达式
{
"pageIndex":.pageNo,
"pageSize":.pageSize,
"total":.total,
"haveNextPaga":if((.total - .pageNo * .pageSize) > 0) true else false,
"data":[for(.) {*:.}]
}
// 入参：
{
"pageNo":1,
"pageSize":2,
"total":100,
"list":[
{
"name":"nameTest",
"age":10,
"sex":"男",
"married":false,
"education":"小学生"
},
{
"name":"nameTest2",
"age":102,
"sex":"女",
"married":true,
"education":"女博士"
}
]
}
// 结果：
{
"pageIndex" : 1,
"pageSize" : 2,
"total" : 100,
"haveNextPaga" : true,
"data" : [ {
"key" : "pageNo",
"value" : 1
}, {
"key" : "pageSize",
"value" : 2
}, {
"key" : "total",
"value" : 100
}, {
"key" : "list",
"value" : [ {
"name" : "nameTest",
"age" : 10,
"sex" : "男",
"married" : false,
"education" : "小学生"
}, {
"name" : "nameTest2",
"age" : 102,
"sex" : "女",
"married" : true,
"education" : "女博士"
} ]
} ]
}
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6.取集合中的某一个对象
// jslt表达式
{"data1":.[0].name,"data2":.[0].age}
// 入参：
[
{
"name":"nameTest",
"age":10,
"sex":"男",
"married":false,
"education":"小学生"
},
{
"name":"nameTest2",
"age":102,
"sex":"女",
"married":true,
"education":"女博士"
}
]
// 结果：{
"data1" : "nameTest",
"data2" : 10
}
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标签：转换,name,jslt,对象,age,married,sex,JSLT,education 来源： https://www.cnblogs.com/taocong/p/14202651.html