Fastjson 实现类导出json文件

墨蓝 2022-10-16 06:11 144阅读 0赞

# 0.背景 #

利用fastjson实现 java类导出json文件

依赖：

<dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>fastjson</artifactId>
        <version>${fastjson.version}</version>
    </dependency>

# ![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxODU0Mjkx_size_16_color_FFFFFF_t_70][] #

# 1.定义类 #

import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.OutputStreamWriter;
    import java.nio.charset.StandardCharsets;
    import java.util.Map;
    
    public class MqttJson {
        private int[] dev_ids;
        private String msg_type;
        private Map<String,Integer> control_command;
    
        public int[] getDev_ids() {
            return dev_ids;
        }
    
        public void setDev_ids(int[] dev_ids) {
            this.dev_ids = dev_ids;
        }
    
        public String getMsg_type() {
            return msg_type;
        }
    
        public void setMsg_type(String msg_type) {
            this.msg_type = msg_type;
        }
    
        public Map<String, Integer> getControl_command() {
            return control_command;
        }
    
        public void setControl_command(Map<String, Integer> control_command) {
            this.control_command = control_command;
        }
    
        //导出函数
        public static void save(String filename,String json) throws IOException {
            OutputStreamWriter osw=new OutputStreamWriter(new FileOutputStream(filename), StandardCharsets.UTF_8);
            osw.write(json);
            osw.flush();
            osw.close();
        }
    }

# 2.赋值以及转化导出 #

public void class2json()throws IOException {
        MqttJson mqttJson = new MqttJson();
        mqttJson.setDev_ids(String2int(ids));
        mqttJson.setMsg_type("CONTROLCOMMAND");
        Map<String, Integer> contol_comand = new HashMap<String, Integer>(){
            {
                put("stack_flag", 1);
                put("record_log_flag", 1);
            }
        };
        mqttJson.setControl_command(contol_comand);
        String json= JSON.toJSONString(mqttJson);
        mqttJson.save("D://CONTROL_COMMAND.json",json);
    }

# 3.JSON效果 #

{
        "control_command":{"record_log_flag":1,"stack_flag":1},
        "dev_ids":[1,2,3,4,5],
        "msg_type":"CONTROLCOMMAND"
    }

![20210527114429603.png][]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxODU0Mjkx_size_16_color_FFFFFF_t_70]: /images/20221014/906b90097a294140a6183b65ca71db35.png
[20210527114429603.png]: /images/20221014/ff7641d714e2424ba2cc89de83b7f4ab.png