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/