Java操作json的通用类

来源：互联网发布：falcon猎鹰手表知乎编辑：程序博客网时间：2024/05/18 03:15

http://blog.csdn.net/cyjchao/article/details/4397894

注：除了依赖com.baiyyy.polabs.util.DateUtil;包相关的方法之外，其他方法都在MyEclipse2015+JDK1.7中验证通过

package com.baiyyy.polabs.util.json;

import java.text.ParseException;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import com.baiyyy.polabs.util.DateUtil;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.JsonConfig;
import net.sf.json.util.CycleDetectionStrategy;

/**
* 处理json的工具类，负责json数据转换成java对象和java对象转换成json
*
* @author yongtree
* @date 2008-11-22 上午10:47:13
* @version 1.0
*/
public class JsonUtil {

/**
* 从一个JSON 对象字符格式中得到一个java对象
*
* @param jsonString
* @param pojoCalss
* @return
*/
public static Object getObject4JsonString(String jsonString, Class pojoCalss) {
Object pojo;
JSONObject jsonObject = JSONObject.fromObject(jsonString);
pojo = JSONObject.toBean(jsonObject, pojoCalss);
return pojo;
}

/**
* 从json HASH表达式中获取一个map，改map支持嵌套功能
*
* @param jsonString
* @return
*/
public static Map getMap4Json(String jsonString) {
JSONObject jsonObject = JSONObject.fromObject(jsonString);
Iterator keyIter = jsonObject.keys();
String key;
Object value;
Map valueMap = new HashMap();

while (keyIter.hasNext()) {
key = (String) keyIter.next();
value = jsonObject.get(key);
valueMap.put(key, value);
}

return valueMap;
}

/**
* 从json数组中得到相应java数组
*
* @param jsonString
* @return
*/
public static Object[] getObjectArray4Json(String jsonString) {
JSONArray jsonArray = JSONArray.fromObject(jsonString);
return jsonArray.toArray();

}

/**
* 从json对象集合表达式中得到一个java对象列表
*
* @param jsonString
* @param pojoClass
* @return
*/
public static List getList4Json(String jsonString, Class pojoClass) {

JSONArray jsonArray = JSONArray.fromObject(jsonString);
JSONObject jsonObject;
Object pojoValue;

List list = new ArrayList();
for (int i = 0; i < jsonArray.size(); i++) {

jsonObject = jsonArray.getJSONObject(i);
pojoValue = JSONObject.toBean(jsonObject, pojoClass);
list.add(pojoValue);

}
return list;

}

/**
* 从json数组中解析出java字符串数组
*
* @param jsonString
* @return
*/
public static String[] getStringArray4Json(String jsonString) {

JSONArray jsonArray = JSONArray.fromObject(jsonString);
String[] stringArray = new String[jsonArray.size()];
for (int i = 0; i < jsonArray.size(); i++) {
stringArray[i] = jsonArray.getString(i);

}

return stringArray;
}

/**
* 从json数组中解析出javaLong型对象数组
*
* @param jsonString
* @return
*/
public static Long[] getLongArray4Json(String jsonString) {

JSONArray jsonArray = JSONArray.fromObject(jsonString);
Long[] longArray = new Long[jsonArray.size()];
for (int i = 0; i < jsonArray.size(); i++) {
longArray[i] = jsonArray.getLong(i);

}
return longArray;
}

/**
* 从json数组中解析出java Integer型对象数组
*
* @param jsonString
* @return
*/
public static Integer[] getIntegerArray4Json(String jsonString) {

JSONArray jsonArray = JSONArray.fromObject(jsonString);
Integer[] integerArray = new Integer[jsonArray.size()];
for (int i = 0; i < jsonArray.size(); i++) {
integerArray[i] = jsonArray.getInt(i);

}
return integerArray;
}

/**
* 从json数组中解析出java Date 型对象数组，使用本方法必须保证
*
* @param jsonString
* @return
* @throws ParseException
*/
public static Date[] getDateArray4Json(String jsonString, String DataFormat)
throws ParseException {

JSONArray jsonArray = JSONArray.fromObject(jsonString);
Date[] dateArray = new Date[jsonArray.size()];
String dateString;
Date date;

for (int i = 0; i < jsonArray.size(); i++) {
dateString = jsonArray.getString(i);
date = DateUtil.parseDate(dateString, DataFormat);
dateArray[i] = date;

}
return dateArray;
}

/**
* 从json数组中解析出java Integer型对象数组
*
* @param jsonString
* @return
*/
public static Double[] getDoubleArray4Json(String jsonString) {

JSONArray jsonArray = JSONArray.fromObject(jsonString);
Double[] doubleArray = new Double[jsonArray.size()];
for (int i = 0; i < jsonArray.size(); i++) {
doubleArray[i] = jsonArray.getDouble(i);

}
return doubleArray;
}

/**
* 将java对象转换成json字符串
*
* @param javaObj
* @return
*/
public static String getJsonString4JavaPOJO(Object javaObj) {

JSONObject json;
json = JSONObject.fromObject(javaObj);
return json.toString();

}

/**
* 将java对象转换成json字符串,并设定日期格式
*
* @param javaObj
* @param dataFormat
* @return
*/
public static String getJsonString4JavaPOJO(Object javaObj,
String dataFormat) {

JSONObject json;
JsonConfig jsonConfig = configJson(dataFormat);
json = JSONObject.fromObject(javaObj, jsonConfig);
return json.toString();

}

/**
* JSON 时间解析器具
*
* @param datePattern
* @return
*/
public static JsonConfig configJson(String datePattern) {
JsonConfig jsonConfig = new JsonConfig();
jsonConfig.setExcludes(new String[] { "" });
jsonConfig.setIgnoreDefaultExcludes(false);
jsonConfig.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);
jsonConfig.registerJsonValueProcessor(Date.class,
new JsonDateValueProcessor(datePattern));

return jsonConfig;
}

/**
* 除去不想生成的字段（特别适合去掉级联的对象）+时间转换
* @param excludes 除去不想生成的字段
* @param datePattern
* @return
*/
public static JsonConfig configJson(String[] excludes, String datePattern) {
JsonConfig jsonConfig = new JsonConfig();
jsonConfig.setExcludes(excludes);
jsonConfig.setIgnoreDefaultExcludes(true);
jsonConfig.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);
jsonConfig.registerJsonValueProcessor(Date.class,
new JsonDateValueProcessor(datePattern));

return jsonConfig;
}

}

package com.baiyyy.polabs.util.json;

import java.text.SimpleDateFormat;
import java.util.Date;

import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonValueProcessor;

/**
*
* @author yongtree
* @date 2008-11-22 上午10:54:19
* @version 1.0
*/
public class JsonDateValueProcessor implements JsonValueProcessor {

private String format = "yyyy-MM-dd HH:mm:ss";

public JsonDateValueProcessor() {

}

public JsonDateValueProcessor(String format) {
this.format = format;
}

public Object processArrayValue(Object value, JsonConfig jsonConfig) {
String[] obj = {};
if (value instanceof Date[]) {
SimpleDateFormat sf = new SimpleDateFormat(format);
Date[] dates = (Date[]) value;
obj = new String[dates.length];
for (int i = 0; i < dates.length; i++) {
obj[i] = sf.format(dates[i]);
}
}
return obj;
}

public Object processObjectValue(String key, Object value, JsonConfig jsonConfig) {
if (value instanceof Date) {
String str = new SimpleDateFormat(format).format((Date) value);
return str;
}
return value == null ? null : value.toString();
}

public String getFormat() {
return format;
}

public void setFormat(String format) {
this.format = format;
}

}

0 0