jsonObject的使用

        在项目中难免会用java处理json格式的数据，因此封装了一个JSONUtil工具类。

JSONUtil.java

package com.bijian.json.study;

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

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
	 */
	public static Date[] getDateArray4Json(String jsonString, String DataFormat) {

		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.stringToDate(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 DateJsonValueProcessor(datePattern));
		return jsonConfig;
	}

	/**
	 * @param excludes
	 * @param datePattern
	 * @return
	 */
	public static JsonConfig configJson(String[] excludes,String datePattern) {

		JsonConfig jsonConfig = new JsonConfig();
		jsonConfig.setExcludes(excludes);
		jsonConfig.setIgnoreDefaultExcludes(false);
		jsonConfig.setCycleDetectionStrategy(CycleDetectionStrategy.LENIENT);
		jsonConfig.registerJsonValueProcessor(Date.class,new DateJsonValueProcessor(datePattern));
		return jsonConfig;
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Object obj01 = getObject4JsonString("{'name':'bijian','age':'30','phone':'13899998888'}", TestObject.class);
		System.out.println(obj01);
		
		Object[] obj = getObjectArray4Json("['json','is','easy']");
		for(Object o: obj) {
			System.out.println(o);
		}
		
		Map map = getMap4Json("{'json':'001','is':'002','easy':'003'}");
		System.out.println(map);
	}
}

DateUtil.java

package com.bijian.json.study;

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

public class DateUtil {

	public static Date stringToDate(String dateString, String dataFormat) {

		SimpleDateFormat sdf = new SimpleDateFormat(dataFormat);
		Date date = null;
		try {
			date = sdf.parse(dateString);
		} catch (ParseException e) {
			e.printStackTrace();
		}
		return date;
	}
}

DateJsonValueProcessor.java

package com.bijian.json.study;

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

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

public class DateJsonValueProcessor implements JsonValueProcessor {

	public static final String DEFAULT_DATE_PATTERN = "yyyy-MM-dd";

	private DateFormat dateFormat;

	/**
	 * 构造方法.
	 * 
	 * @param datePattern
	 *            日期格式
	 */
	public DateJsonValueProcessor(String datePattern) {

		if (null == datePattern) {
			dateFormat = new SimpleDateFormat(DEFAULT_DATE_PATTERN);
		}else {
			dateFormat = new SimpleDateFormat(datePattern);
		}
	}

	/*
	 * （非 Javadoc）
	 * 
	 * @see net.sf.json.processors.JsonValueProcessor#processArrayValue(java.
	 * lang.Object, net.sf.json.JsonConfig)
	 */
	public Object processArrayValue(Object arg0, JsonConfig arg1) {

		// TODO 自动生成方法存根
		return process(arg0);
	}

	/*
	 * （非 Javadoc）
	 * 
	 * @see net.sf.json.processors.JsonValueProcessor#processObjectValue(java
	 * .lang.String, java.lang.Object, net.sf.json.JsonConfig)
	 */
	public Object processObjectValue(String arg0, Object arg1, JsonConfig arg2) {
		return process(arg1);
	}

	private Object process(Object value) {
		return dateFormat.format((Date) value);
	}
}

TestObject.java

package com.bijian.json.study;

public class TestObject {

	private String name;
	private int age;
	private String phone;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getAge() {
		return age;
	}
	public void setAge(int age) {
		this.age = age;
	}
	public String getPhone() {
		return phone;
	}
	public void setPhone(String phone) {
		this.phone = phone;
	}
}

JSONUtil.java中的main方法运行结果：

com.bijian.json.study.TestObject@56f631
json
is
easy
{is=002, easy=003, json=001}

 

文章来源：http://blog.163.com/caoyanhua_05/blog/static/63966999200911184219995/