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This article mainly introduces "Java objects and Json text how to achieve conversion", in daily operation, I believe many people in Java objects and Json text how to achieve conversion problems have doubts, small series consulted all kinds of information, sorted out simple and easy to use operation methods, hope to answer "Java objects and Json text how to achieve conversion" doubts helpful! Next, please follow the small series to learn together!

Json is a tool class for converting Java objects and Json text to and from each other.

Install and download the source code git clone https://github.com/njdi/durian.git compile source code cd durian/

Switch to the latest version (Tag), such as: 0.4,

git checkout 0.4

Compile and install to local Maven repository:

mvn clean package add dependencies

To use Config for SpringBoot apps, you need to add:

io.njdi durian-common ${version}

${version} is replaced with a specific version number, such as 0.4.

Java objects

Java objects support the following types: primitive data types, arrays, lists, dictionaries.

basic data types

Integer/int

Long/long

Float/float

Double/double

Boolean/boolean

String

array

int[]

long[]

float[]

double[]

boolean[]

String[]

list

List

List

List

List

List

List

List

dictionary

Map

Map

Map

Map

Map

Map

Map

class

Class

Java objects converted to Json text

Java objects can be converted to Json text using the following methods:

Json.toJson(obj) Basic data type String json;json = Json.toJson(1);json = Json.toJson (1.0);json = Json.toJson(true);json = Json.toJson("str"); array String json;json = Json.toJson (new int[]{1, 2, 3});json = Json.toJson (new double[]{1.0, 2.0, 3.0});json = Json.toJson (new boolean[]{true, false});json = Json.toJson (new String[]{"1", "2.0", "true"}); List String json;json = Json.toJson (List.of(1, 2, 3));json = Json.toJson (List.of(1.0, 2.0, 3.0));json = Json.toJson (List.of(true, false));json = Json.toJson (List.of("1", "2.0", "true")); Dictionary String json;json = Json.toJson (Map.of("key1", 1, "key2", 2));json = Json.toJson (Map.of("key1", 1.0, "key2", 2.0));json = Json.toJson (Map.of("key1", true, "key2", false));json = Json.toJson (Map.of("key1", "str", "key2", "2.0")); class public static class MyObject { private int a; private double b; private boolean c; private String d;}MyObject object = new MyObject();object.a = 1;object.b = 2.0;object.c = true;object.d = "str";String json = Json.toJson(object);Json Text to Java object

When converting Json text to Java object, you need to specify the type information of the converted object through parameters:

Json.fromJson(json, Class)

or

Json.fromJson(json, Type) Basic data type

When converting Json text to basic data types, you need to specify the conversion type with Type, such as:

int a = Json.fromJson("1", Json.JsonType.INT);

Correspondence between basic data types and types:

Integer/int -> Json.JsonType.INT

Long/long -> Json.JsonType.LONG

Float/float -> Json.JsonType.FLOAT

Double/double -> Json.JsonType.DOUBLE

Boolean/boolean -> Json.JsonType.BOOLEAN

String -> Json.JsonType.STRING

array

When converting a Json text to an array, you need to use Type to specify the element type of the converted array, such as:

int[] arr = Json.fromJson("[1, 2, 3]", Json.JsonType.INT_ARRAY);

Correspondence between element type and Type of array:

int[] -> Json.JsonType.INT_ARRAY

long[] -> Json.JsonType.LONG_ARRAY

float[] -> Json.JsonType.FLOAT_ARRAY

double[] -> Json.JsonType.DOUBLE_ARRAY

boolean[] -> Json.JsonType.BOOLEAN_ARRAY

String[] -> Json.JsonType.STRING_ARRAY

list

When converting a Json text to a list, you need to use Type to specify the element type of the conversion list, such as:

List list = Json.fromJson("[1, 2, 3]", Json.JsonType.INT_LIST);

Correspondence between element type and Type of list:

List -> Json.JsonType.INT_LIST

List -> Json.JsonType.LONG_LIST

List -> Json.JsonType.FLOAT_LIST

List -> Json.JsonType.DOUBLE_LIST

List -> Json.JsonType.BOOLEAN_LIST

List -> Json.JsonType.STRING_LIST

List

dictionary

When converting Json text to dictionary, you need to use Type to specify the element value type of the conversion dictionary, such as:

Map map = Json.fromJson("{'a': 1, 'b': 2}", Json.JsonType.INT_MAP);

Map -> Json.JsonType.INT_MAP

Map -> Json.JsonType.LONG_MAP

Map -> Json.JsonType.FLOAT_MAP

Map -> Json.JsonType.DOUBLE_MAP

Map -> Json.JsonType.BOOLEAN_MAP

Map -> Json.JsonType.STRING_MAP

Map -> Json.JsonType.OBJECT_MAP

class

When converting a Json text to a class object, you need to use Class to specify the type of the converted object, such as:

MyObject obj = Json.fromJson("{'a': 1, 'b': 2.0, 'c': true, d: 'str'}", MyObject.class); This concludes the study of "how to convert Java objects and Json texts", hoping to solve everyone's doubts. Theory and practice can better match to help everyone learn, go and try it! If you want to continue learning more relevant knowledge, please continue to pay attention to the website, Xiaobian will continue to strive to bring more practical articles for everyone!

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