JSON与Java的两种解析方式

### 1. 使用Java内置的JSON库
Java 8及更高版本提供了内置的JSON库，用于解析和生成JSON数据。
解析JSON
ava
import java.nio.file.Files;
import java.nio.file.Paths;
import java.io.IOException;
import javax.json.Json;
import javax.json.JsonObject;
import javax.json.JsonReader;
import javax.json.JsonReaderFactory;
import javax.json.JsonStructure;
public class Main {
public static void main(String[] args) {
String jsonString = "{ \"name\": \"John\", \"age\": 30 }";
// 解析JSON字符串
JsonReaderFactory factory = Json.createReaderFactory(null);
try (JsonReader reader = factory.createReader(jsonString)) {
JsonStructure jsonStructure = reader.read();
if (jsonStructure instanceof JsonObject) {
JsonObject jsonObject = (JsonObject) jsonStructure;
String name = jsonObject.getString("name");
int age = jsonObject.getInt("age");
System.out.println("Name: " + name);
System.out.println("Age: " + age);
 
#### 生成JSON
java
import javax.json.Json;
import javax.json.JsonObject;
import javax.json.JsonWriter;
import javax.json.JsonWriterFactory;
import javax.json.stream.JsonGenerator;
import java.io.StringWriter;
public class Main {
public static void main(String[] args) {
// 创建一个JsonObject
JsonObject jsonObject = Json.createObjectBuilder()
.add("name", "John")
.add("age", 30).build();
// 将JsonObject转换为JSON字符串
StringWriter stringWriter = new StringWriter();
(JsonWriterjsonWriter= Json.createWriterFactory(null).createWriter(stringWriter)) {
jsonWriter.writeObject(jsonObject);
String jsonString = stringWriter.toString();
System.out.println(jsonString);  // 输出: {"name":"John","age":30}
### 2. 使用第三方库（例如Gson）
Gson是一个非常流行的JSON处理库，提供了简洁易用的API。
#### 添加依赖（Maven）
xml
<dependency>
<groupId>com.google.code.gson</groupId>
<artifactId>gson</artifactId>
<version>2.8.9</version>
</dependency>
#### 解析JSON
java
import com.google.gson.Gson;
import com.google.gson.JsonObject;
public class Main {
public static void main(String[] args) {
String jsonString = "{ \"name\": \"John\", \"age\": 30 }";
Gson gson = new Gson();
JsonObject jsonObject = gson.fromJson(jsonString, JsonObject.class);
String name = jsonObject.get("name").getAsString();
int age = jsonObject.get("age").getAsInt();
System.out.println("Name: " + name);
System.out.println("Age: " + age);
}
#### 生成JSON
java
import com.google.gson.Gson;
import com.google.gson.JsonObject;
public class Main {
public static void main(String[] args) {
JsonObject jsonObject = new JsonObject();
jsonObject.addProperty("name", "John");
jsonObject.addProperty("age", 30);
Gson gson = new Gson();
String jsonString = gson.toJson(jsonObject);
System.out.println(jsonString);  // 输出: {"name":"John","age":30}