Java实现的JSONUtil工具类与用法示例

时间：2020-10-21 20:59:51|栏目：JAVA代码|点击：次

本文实例讲述了Java实现的JSONUtil工具类与用法。分享给大家供大家参考，具体如下：

import java.util.HashMap;
import java.util.Map;
import com.alibaba.druid.util.StringUtils;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
public class JSONUtils {
  /**
   * Bean对象转JSON
   *
   * @param object
   * @param dataFormatString
   * @return
   */
  public static String beanToJson(Object object, String dataFormatString) {
    if (object != null) {
      if (StringUtils.isEmpty(dataFormatString)) {
        return JSONObject.toJSONString(object);
      }
      return JSON.toJSONStringWithDateFormat(object, dataFormatString);
    } else {
      return null;
    }
  }
  /**
   * Bean对象转JSON
   *
   * @param object
   * @return
   */
  public static String beanToJson(Object object) {
    if (object != null) {
      return JSON.toJSONString(object);
    } else {
      return null;
    }
  }
  /**
   * String转JSON字符串
   *
   * @param key
   * @param value
   * @return
   */
  public static String stringToJsonByFastjson(String key, String value) {
    if (StringUtils.isEmpty(key) || StringUtils.isEmpty(value)) {
      return null;
    }
    Map<String, String> map = new HashMap<String, String>();
    map.put(key, value);
    return beanToJson(map, null);
  }
  /**
   * 将json字符串转换成对象
   *
   * @param json
   * @param clazz
   * @return
   */
  public static Object jsonToBean(String json, Object clazz) {
    if (StringUtils.isEmpty(json) || clazz == null) {
      return null;
    }
    return JSON.parseObject(json, clazz.getClass());
  }
  /**
   * json字符串转map
   *
   * @param json
   * @return
   */
  @SuppressWarnings("unchecked")
  public static Map<String, Object> jsonToMap(String json) {
    if (StringUtils.isEmpty(json)) {
      return null;
    }
    return JSON.parseObject(json, Map.class);
  }
}

测试：

JSON字符串转map

public static void main(String[] args) {
    String jsonStr = "{'userName':'huangbaokang','password':'123456'}";
    Map<String, Object> map = JSONUtils.jsonToMap(jsonStr);
    System.out.println(map.get("userName"));
}

输出：

huangbaokang

JSON字符串转对象：

新建User类

public class User {
  private String userName;
  private String password;
  public String getUserName() {
    return userName;
  }
  public void setUserName(String userName) {
    this.userName = userName;
  }
  public String getPassword() {
    return password;
  }
  public void setPassword(String password) {
    this.password = password;
  }
}
public static void main(String[] args) {
    String jsonStr = "{'userName':'huangbaokang','password':'123456'}";
    User user = (User) JSONUtils.jsonToBean(jsonStr, new User());
    System.out.println("用户名="+user.getUserName()+" 密码="+user.getPassword());
}

测试输出：

输出用户名=huangbaokang 密码=123456

对象转JSON

public static void main(String[] args) {
    User user = new User();
    user.setUserName("huangbaokang");
    user.setPassword("123456");
    String result = JSONUtils.beanToJson(user);
    System.out.println(result);
}

测试输出：