Snack

A Json Dom & JsonPath Framework (for Java)

Compatible with `jayway.jsonpath` and IETF JSONPath (RFC 9535) standards

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Language: English | 中文

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jdk8 based. Support: Json Dom construction, encoding and decoding, fetching, JsonPath query, JsonSchema validation.

<dependency>
  <groupId>org.noear</groupId>
  <artifactId>snack4-jsonpath</artifactId>
  <version>4.0.0-SNAPSHOT</version>
</dependency>

Snach-jsonpath draws on the design of Javascript where all variables are declared with var and Xml dom where everything is Node. Everything underneath it is represented by an ONode, which stands for One node and can be converted to any type.

• It emphasizes the ability to build and manipulate the document tree
• High performance Json path queries (much faster than jayway.jsonpath), Compatible with jayway.jsonpath and IETF JSONPath (RFC 9535) standards (Switch with optoins)
• Supports Json Schema validation
• Prefer no-argument constructors + field codec (reduces the risk of triggering actions by injection)

dependencies	description
org.noear:snack4	Provides basic support for dom construction and codec
org.noear:snack4-jsonpath	Provides json path query support
org.noear:snack4-jsonschema	Provides json schema validation support

JSONPath syntax reference(IETF JSONPath (RFC 9535))

Syntax Element	Description
$	root node identifier
@	current node identifier (valid only within filter selectors)
[<selectors>]	child segment: selects zero or more children of a node
.name	shorthand for ['name']
.*	shorthand for [*]
..[<selectors>]	descendant segment: selects zero or more descendants of a node
..name	shorthand for ..['name']
..*	shorthand for ..[*]
'name'	name selector: selects a named child of an object
*	wildcard selector: selects all children of a node
3	index selector: selects an indexed child of an array (from 0)
0:100:5	array slice selector: start:end:step for arrays
?<logical-expr>	filter selector: selects particular children using a logical expression
fun(@.foo)	filter function extension: invokes a function in a filter expression
.fun()	aggregate function

Filter selector syntax reference:

Syntax	Description	Precedence
(...)	Grouping	5
name(...)	Function Expressions	5
!	Logical NOT	4
==,!=,<,<=,>,>=	Relations	3
&&	Logical AND	2
||	Logical OR	1

examples

Support dom manipulation

ONode oNode = new ONode();
oNode.set("id", 1);
oNode.getOrNew("layout").then(o -> {
    o.addNew().set("title", "开始").set("type", "start");
    o.addNew().set("title", "结束").set("type", "end");
});

oNode.get("id").getInt();
oNode.get("layout").get(0).get("title").getString();

oNode.getOrNew("list").fillJson("[1,2,3,4,5,6]");

Supports json path query, build, and delete

ONode.ofBean(store).select("$..book[?@.tags contains 'war'].first()").toBean(Book.class); //RFC9535 规范，可以没有括号
ONode.ofBean(store).select("$..book[?(!(@.category == 'fiction') && @.price < 40)].first()").toBean(Book.class);
ONode.ofJson(store).select("$.store.book.count()");

ONode.ofBean(store).create("$.store.book[0].category").toJson();

ONode.ofBean(store).delete("$..book[-1]");

Supports json schema validation

JsonSchema schema = JsonSchema.ofJson("{type:'object',properties:{userId:{type:'string'}}}"); //加载架构定义

schema.validate(ONode.load("{userId:'1'}")); //校验格式

Supports serialization and deserialization

User user = new User();
ONode.ofBean(user).toBean(User.class); //可以作为 bean 转换使用
ONode.ofBean(user).toJson();

ONode.ofJson("{}").toBean(User.class);
ONode.ofJson("[{},{}]").toBean((new ArrayList<User>(){}).getClass());

//快捷方式
String json = ONode.serialize(user);
User user = ONode.deserialize(json, User.class);

Path tree interface

ONode o = ONode.ofJson(json).usePaths(); //会为每个子节点，生成 path 属性

ONode rst = o.select("$.data.list[*].mobile");
List<String> rstPaths = rst.pathList(); //获取结果节点的路径列表
for(ONode n1 : rst.getArray()) {
   n1.path(); //当前路径
   n1.parent(); //父级节点
}

ONode rst = o.get("data").get("list").get(2);
rst.path();
rst.parent();

Advanced customization

Options options = Options.of();
//添加编码器
options.addEncoder(Date.class, (ctx, value, target) -> {
    target.setValue(DateUtil.format(data, "yyyy-MM-dd"));
});
//添加解码器
options.addDecoder(Date.class, ...);
options.addFactory(...);

//添加特性
options.addFeature(Feature.Write_PrettyFormat);

//移除特性
options.removeFeature(Feature.Write_PrettyFormat);

//设置日期格式附
options.addFeature(Feature.Write_UseDateFormat); //使用日期格式
options.dateFormat("yyyy-MM");

//..

String json = ONode.ofBean(orderModel, options).toJson();