Java中怎样使用JSON进行文件解析

{"reason":
"success","result":
[{"id":1,"firstLetter":"A","brandName":"奥迪","brandLogo":"http"},
{"id":2,"firstLetter":"A","brandName":"雷克萨斯","brandLogo":"http"},
{"id":3,"firstLetter":"A","brandName":"奔驰","brandLogo":"ghjvh"}]

//实体数据
PoliceStation ps1=new PoliceStation();
		ps1.setName("电子城派出所");
		ps1.setAddr("雁塔区电子二路");
		ps1.setTel("1234567890");
		//序列化：将Java对象转换成json格式的数据
		String s1=JSON.toJSONString(ps1);
		System.out.println(s1);

//反序列化：将json格式的字符串转换成Java对象
		String s2="{\"addr\":\"雁塔区电子二路\",
                        \"name\":\"电子城派出所\",
                         \"tel\":\"1234567890\"}\r\n }";
		PoliceStation ps2= JSON.parseObject(s2,PoliceStation.class);
		System.out.println(ps2);

// json格式数据
String jsonStr = "[{ \"name\": \"文保分局沪东高校派出所\", \"addr\": \"中山北一路801号\", 			\"tel\": \"22027732\" 		}, { 			\"name\": \"文保分局沪西高校派出所\", 			\"addr\": \"芙蓉江路55号\", 			\"tel\": \"62751704\" 		}, { 			\"name\": \"水上公安局吴淞水上派出所\", 			\"addr\": \"淞浦路187号\", 			\"tel\": \"56671442\" 		}, { 			\"name\": \"水上公安局杨浦水上派出所\", 			\"addr\": \"杨树浦路1291号\", 			\"tel\": \"65898004\" 		}, { 			\"name\": \"水上公安局外滩水上派出所\", 			\"addr\": \"中山东二路8弄3号\", 			\"tel\": \"63305388\" 		}, { 			\"name\": \"水上公安局石洞口水上派出所\", 			\"addr\": \"盛石路18号\", 			\"tel\": \"56152176\" 		}, { 			\"name\": \"轨道分局上海火车站站派出所\", 			\"addr\": \"共和新路2838号\", 			\"tel\": \"56650472\" 		}, { 			\"name\": \"轨道分局徐家汇站派出所\", 			\"addr\": \"沪闵路6707号\", 			\"tel\": \"63189188*70246\" 		}, { 			\"name\": \"轨道分局人民广场站派出所\", 			\"addr\": \"南京西路19号\", 			\"tel\": \"63189188*76369\" 		}, { 			\"name\": \"轨道分局陆家嘴站派出所\", 			\"addr\": \"龙阳路1990号乙\", 			\"tel\": \"63189188*27132\" 		}, { 			\"name\": \"轨道分局宜山路站派出所\", 			\"addr\": \"零陵路668号\", ... \"崇明县公安局新村派出所\", 			\"addr\": \"新村乡新中村新跃160号\", 			\"tel\": \"59650598\" 		}, { 			\"name\": \"崇明县公安局新海派出所\", 			\"addr\": \"新海农场场部北侧\", 			\"tel\": \"59655712\" 		}, { 			\"name\": \"崇明县公安局长征派出所\", 			\"addr\": \"长征农场派出所生活区长征农场场部\", 			\"tel\": \"59311459\" 		}, { 			\"name\": \"崇明县公安局长江派出所\", 			\"addr\": \"东风农场林风公路1579号\", 			\"tel\": \"59641914\" 		}, { 			\"name\": \"崇明县公安局东旺派出所\", 			\"addr\": \"前哨农场前哨公路18号\", 			\"tel\": \"59471109\" 		}, { 			\"name\": \"崇明县公安局东滩湿地保护区治安派出所\", 			\"addr\": \"陈家镇瀛陈公路崇明县团结沙\", 			\"tel\": \"59404611\" 		}, { 			\"name\": \"崇明县公安局长兴派出所\", 			\"addr\": \"长兴镇海舸路659号\", 			\"tel\": \"56851431\" 		}, { 			\"name\": \"崇明县公安局横沙派出所\", 			\"addr\": \"民东路1588号\", 			\"tel\": \"24060670\" 		}]";
List<PoliceStation> stationList = JSON.parseArray(jsonStr, PoliceStation.class);
for(PoliceStation ps : stationList) {
    System.out.println("警局名称：" + ps.getName());
    System.out.println("警局地址：" + ps.getAddr());
    System.out.println("联系电话：" + ps.getTel());
}

Map<String, Object> map = new HashMap<String, Object>(){
    {
        put("age", 20);
        put("name", "灰灰");
        put("sex", null);
    }
};
System.out.println(JSONObject.toJSONString(map));
//输出结果
{"name:"灰灰","age":20}

Map<String, Object> map = new HashMap<String, Object>(){
    {
        put("age", 20);
        put("name", "灰灰");
        put("sex", null);
    }
};
// 使用Feature类型的枚举值进行设置
System.out.println(JSONObject.toJSONString(map,Feature.WriteMapNullValue));

//实体类
public class PoliceStation {
	private String name;
	private String addr;
	private String tel;
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getAddr() {
		return addr;
	}
	public void setAddr(String addr) {
		this.addr = addr;
	}
	public String getTel() {
		return tel;
	}
	public void setTel(String tel) {
		this.tel = tel;
	}
}

//测试类
PoliceStation ps = new PoliceStation();
ps.setName("电子城派出所");
ps.setAddr("雁塔区电子二路343号");
ps.setTel("13324554332");
System.out.println(JSON.toJSONString(ps));
//输出结果
{"addr":"雁塔区电子二路343号","name":"电子城派出所","tel":"13324554332"}

import com.alibaba.fastjson2.annotation.JSONField;
public class PoliceStation {
	@JSONField(ordinal = 1)
	private String name;
	@JSONField(ordinal = 2)
	private String addr;
	@JSONField(ordinal = 3)
	private String tel;
}

//实体类
// 订单类
public class Order{
    // 订单编号
	private String orderId;
    // 创建日期
	private LocalDateTime creationTime;
	public Order() {
		this.orderId = UUID.randomUUID().toString();
		this.creationTime = LocalDateTime.now();
	}
	public String getOrderId() {
		return orderId;
	}
	public void setOrderId(String orderId) {
		this.orderId = orderId;
	}
	public LocalDateTime getCreationTime() {
		return creationTime;
	}
	public void setCreationTime(LocalDateTime creationTime) {
		this.creationTime = creationTime;
	}
}

//测试类
public class Test {
	public static void main(String[] args) {
		Order order1 = new Order();
		String json = JSON.toJSONString(order1);
		System.out.println(json);
	}
}
//输出结果
{"creationTime":"2022-07-10 19:39:07.377","orderId":"dbee4f0c-ced7-463f-b19b-c83234cbd5b0"}

// 订单类
public class Order{
	// 订单编号
	private String orderId;
	// 创建日期
	@JSONField(format = "yyyy-MM-dd HH:mm:ss")
	private LocalDateTime creationTime;
}