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gson 示例教程

import com.google.gson.*;
import org.junit.jupiter.api.Test;

public class GsonExampleTest {
    @Test
    public void testBuildJson() {
        // 手动构建一个JSON对象
        JsonObject user = new JsonObject();
        user.addProperty("name", "Alice");
        user.addProperty("age", 25);
        user.addProperty("active", true);

        // 添加NULL值
        user.add("nickname", JsonNull.INSTANCE);

        // 添加数组
        JsonArray hobbies = new JsonArray();
        hobbies.add("reading");
        hobbies.add("coding");
        user.add("hobbies", hobbies);

        System.out.println(user.toString());
    }

    @Test
    public void testParseJson() {
        String jsonStr = "{\"name\":\"Alice\",\"age\":25,\"active\":true,\"nickname\":null,\"hobbies\":[\"reading\",\"coding\"]}";
        JsonObject obj = JsonParser.parseString(jsonStr).getAsJsonObject();
        String name = obj.get("name").getAsString();
        int age = obj.get("age").getAsInt();
        System.out.println("name: " + name + " age: " + age);
        // 遍历数组
        for (JsonElement hobby : obj.getAsJsonArray("hobbies")) {
            System.out.println("hobby: " + hobby.getAsString());
        }
    }
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.learn</groupId>
    <artifactId>LearnAndTest</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>8</maven.compiler.source>
        <maven.compiler.target>8</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <version>5.10.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.google.code.gson</groupId>
            <artifactId>gson</artifactId>
            <version>2.10.1</version>
        </dependency>
    </dependencies>

</project>