https://github.com/kenta-shimizu/json4java8
This library is JSON (RFC8259) parser implementation on Java8. Also supports JSONC reading.
https://github.com/kenta-shimizu/json4java8
java java8 json json-api json-parser jsonc jsonc-parser
Last synced: 14 days ago
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This library is JSON (RFC8259) parser implementation on Java8. Also supports JSONC reading.
- Host: GitHub
- URL: https://github.com/kenta-shimizu/json4java8
- Owner: kenta-shimizu
- License: apache-2.0
- Created: 2020-01-17T12:32:22.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2023-07-01T16:16:34.000Z (almost 2 years ago)
- Last Synced: 2025-03-24T15:41:33.077Z (about 1 month ago)
- Topics: java, java8, json, json-api, json-parser, jsonc, jsonc-parser
- Language: Java
- Homepage:
- Size: 376 KB
- Stars: 4
- Watchers: 1
- Forks: 9
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# json4java8
## Introduction
This library is JSON ([RFC8259](https://tools.ietf.org/html/rfc8259)) parser implementation on Java8. Also supports JSONPath, JSONC reading.
## Example of use
```java
public class POJO {
public int num;
public String str;
public boolean bool;
public List array;
public POJO() {
num = 100;
str = "STRING";
bool = true;
array = Arrays.asList("a", "b", "c");
}
public static void main(String[] args) {
POJO pojo = new POJO();
String json = JsonHub.fromPojo(pojo).toJson();
System.out.println(json);
/* {"num":100,"str":"STRING","bool":true,"array":["a","b","c"]} */
}
}
```
[Javadoc](https://kenta-shimizu.github.io/json4java8/index.html)
## Convert
1. Create JsonHub instance from `#fromPojo`, `#fromJson`, `#fromFile`, `#fromBytes`.
1. Convert using `#toPojo`, `#toJson`, `#writeFile`, `#getBytes`, `#writeBytes`.
### From POJO (Plain Old Java Objec) to JSON
```java
/* to String */
String json = JsonHub.fromPojo(pojo).toJson();
/* to Writer */
Writer writer = new StringWriter()
JsonHub.fromPojo(pojo).toJson(writer);
/* to file */
Path path = Paths.get("path/of/file.json");
JsonHub.fromPojo(pojo).writeFile(path);
```
#### From POJO conditions
- Field is `public`
- Field is *not* `static`
See also ["/src/examples/example02/PojoParseToJsonString.java"](/src/examples/example02/PojoParseToJsonString.java)
See also ["/src/examples/example03/PojoWriteJsonToFile.java"](/src/examples/example03/PojoWriteJsonToFile.java)
### From JSON to POJO
```java
/* from JSON String */
String json = "{\"num\": 100, \"str\": \"STRING\", \"bool\": true}";
Pojo pojo = JsonHub.fromJson(json).toPojo(Pojo.class);
/* from Reader */
Reader reader = new StringReader(json);
Pojo pojo = JsonHub.fromJson(reader).toPojo(Pojo.class);
/* from file */
Path path = Paths.get("path/of/file.json");
Pojo pojo = JsonHub.fromFile(path).toPojo(Pojo.class);
```
#### To POJO conditions
- Class has `public new()` (arguments is 0)
- Field is `public`
- Field is *not* `static`
- Field is *not* `final`
See also ["/src/examples/example01/JsonStringParseToPojo.java"](/src/examples/example01/JsonStringParseToPojo.java)
See also ["/src/examples/example04/ReadJsonFileParseToPojo.java"](/src/examples/example04/ReadJsonFileParseToPojo.java)
### From POJO to UTF-8 bytes
```java
/* to bytes */
byte[] bytes = JsonHub.fromPojo(pojo).getBytes();
/* to OutputStream */
OutputStream strm = new ByteArrayOutputStream();
JsonHub.fromPojo(pojo).writeBytes(strm);
```
### From UTF-8 bytes to POJO
```java
/* from bytes */
byte[] bytes = json.getBytes(StandardCharsets.UTF_8);
Pojo pojo = JsonHub.fromBytes(bytes).toPojo(Pojo.class);
/* from InputStream */
InputStream strm = new ByteArrayInputStream(bytes);
Pojo pojo = JsonHub.fromBytes(strm).toPojo(Pojo.class);
```
## Pretty Print
1. Create JsonHub instance from `#fromPojo`, ...
1. PrettyPrint using `#prettyPrint`
```java
/* to String */
String prettyPrintJson = JsonHub.fromPojo(pojo).prettyPrint();
/* write to file */
Path path = Paths.get("path/of/file.json");
JsonHub.fromPojo(pojo).prettyPrint(path);
/* write to Writer */
Writer writer = new StringWriter();
JsonHub.fromPojo(pojo).prettyPrint(writer);
```
See also ["/src/examples/example05/PojoParseToPrettyPrintJsonString.java"](/src/examples/example05/PojoParseToPrettyPrintJsonString.java)
See also ["/src/examples/example06/PojoWritePrettyPrintJsonToFile.java"](/src/examples/example06/PojoWritePrettyPrintJsonToFile.java)
See also ["/src/examples/example09/ChangePrettyPrintFormat.java"](/src/examples/example09/ChangePrettyPrintFormat.java)
## Get value from JsonHub instance
```java
String json
= "{ "
+ " \"num\": 100, "
+ " \"str\": \"STRING\", "
+ " \"bool\": true, "
+ " \"array\": [\"a\", \"b\", \"c\"]"
+ "} ";
JsonHub jh = JsonHub.fromJson(json);
int num = jh.get("num").intValue(); /* 100 */
String str = jh.get("str").toString(); /* "STRING" */
boolean bool = jh.get("bool").booleanValue(); /* true */
String array_0 = jh.get("array").get(0).toString(); /* "a" */
```
See also ["/src/examples/example08/ForEachJsonHub.java"](/src/examples/example08/ForEachJsonHub.java)
### Methods for seek value in OBJECT or ARRAY
✓ is available.
"blank" is throw `JsonHubUnsupportedOperationException`.
| Method | Object | Array | Number | String | true | false | null |
|:--|:-:|:-:|:-:|:-:|:-:|:-:|:-:|
|get(CharSequence) | ✓ | | | | | | | |
|get(String...)| ✓ | | | | | | | |
|get(int)| | ✓ | | | | | | | |
|iterator() | ✓ | ✓ | | | | | |
|stream() | ✓ | ✓ | | | | | |
|forEach(Consumer super JsonHub)| ✓ | ✓ | | | | | |
|forEach(BiConsumer super JsonString, ? super JsonHub)| ✓ | ✓ | | | | | |
|values() | ✓ | ✓ | | | | | |
|keySet() | ✓ | | | | | | |
|containsKey(CharSequence) | ✓ | | | | | | |
|getOrDefault(CharSequence)| ✓ | | | | | | |
|getOrDefault(CharSequence, JsonHub)| ✓ | | | | | | |
### Methods for get value
✓ is available.
"blank" is throw `JsonHubUnsupportedOperationException`.
| Method | Object | Array | Number | String | true | false | null |
|:--|:-:|:-:|:-:|:-:|:-:|:-:|:-:|
|intValue() | | | ✓ | | | | |
|longValue() | | | ✓ | | | | |
|doubleValue() | | | ✓ | | | | |
|booleanValue() | | | | | ✓ | ✓ | |
|optionalInt() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|optionalLong() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|optionalDouble() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|optionalBoolean() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|optionalNumber() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|optionalString() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|length() | ✓ | ✓ | | ✓ | | | |
|isEmpty() | ✓ | ✓ | | ✓ | | | |
|toString() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
### Methods for check type
✓ is available.
| Method | Object | Array | Number | String | true | false | null |
|:--|:-:|:-:|:-:|:-:|:-:|:-:|:-:|
|type() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|isObject() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|isArray() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|isNumber() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|isString() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|isTrue() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|isFalse() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|isBoolean() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|isNull() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
|nonNull() | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ | ✓ |
## Create JsonHub instance by builder
Use JsonHubBuilder
```java
JsonHubBuilder jhb = JsonHub.getBuilder();
JsonHub jh = jhb.object(
jhb.pair("str", "STRING"),
jhb.pair("num", 100),
jhb.pair("bool", true),
jhb.pair("array", jhb.array(
jhb.build("a"),
jhb.build("b"),
jhb.build("c")
))
);
String json = jh.toJson();
System.out.println(json);
/* {"str":"STRING","num":100,"bool":true,"array":["a","b","c"]} */
```
See also ["/src/examples/example07/CreateJsonStringByBuilder.java"](/src/examples/example07/CreateJsonStringByBuilder.java)
## JSONPath
JSONPath is ["https://goessner.net/articles/JsonPath/"](https://goessner.net/articles/JsonPath/)
### Supports
| Operator | Description |
|:--|:--|
|`$`|The root element.|
|`*`|Wildcard, all object-name or array-number.|
|`..`|Recursive descent.|
|`.`|Child object name operator.|
|`[(, )]`|Child object name(s) operator.|
|`[(, )]`|Child array number(s) operator.|
|`[start:end:step]`|Child array slice operator.|
Not support `@`, `?()`, `()`
```java
List results = jh.jsonPath("$.store.book[*].author");
```
See also ["/src/examples/example11/JsonPath.java"](/src/examples/example11/JsonPath.java)
## JSONC reading
JSONC (JSON with comments) support.
- /* comment... */
- // comment...
- Array trailing comma(,)
- Object trailing comma(,)
```java
Path path = Paths.get("path/of/file.jsonc");
JsonHub jh = JsoncReader.fromFile(path);
System.out.println(jh.prettyPrint());
```
See also ["/src/examples/example10/ReadJsoncFile.java"](/src/examples/example10/ReadJsoncFile.java)