java中String转换成json,json转换成String

前置添加pom

<!-- 配置gson -->
    <dependency>
        <groupId>com.google.code.gson</groupId>
        <artifactId>gson</artifactId>
        <version>2.2.4</version>
    </dependency>

1、json转换成String

import com.google.gson.Gson;

import com.google.gson.GsonBuilder;

class JsonUtil{

public static StringobjectToJsonString(Object obj) {

return createGsonSetDateFormat("yyyy-MM-dd HH:mm:ss").toJson(obj);

}

private static GsoncreateGsonSetDateFormat(String dateFormat) {

return (new GsonBuilder()).setDateFormat(dateFormat).create();

}

}

2、String（json）转换成json

Gson gson = new Gson();
Map<String, Object> map = new HashMap<String, Object>();
map = gson.fromJson(value, map.getClass());
System.out.println(map.toString());
String goodsid=(String) map.get("event");
System.out.println("map的值为:"+goodsid);